Tropical Tidbits from the Tundra

Watching for Lee to develop in the gulf; Katia may need to be watched by Bermuda

By: Levi32, 4:49 PM GMT on August 31, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook (also on Twitter)



The biggest threat to land areas right now is the area of disturbed weather in the NW Caribbean and southern Gulf of Mexico as a tropical wave interacts with a frontal boundary. A surface low may be trying to form in its embryonic stages NNW of the Yucatan Channel. This low will be moving NW over the next couple of days, being steered by a high over the southeastern U.S., and will likely try to deepen in the northwest Gulf of Mexico this weekend. Waters are very warm in here, and there is no competition from the eastern Pacific, which means that there is a lot of energy available that this system will be able to hog all to itself. There is some wind shear over the central gulf, associated with an elongated upper trough over the northern gulf, but this will eventually have to shift north or split as the heat surge from the Caribbean muscles its way northwest. I believe we have a good chance of seeing a tropical depression develop in the box from 25N-30N and 90W-95W, likely during this weekend.

This system will be moving northwest for the next 2-3 days, but as an upper shortwave trough which is currently moving into the Pacific Northwest comes across the mid-west in a few days, the Texas ridge will re-strengthen over northern Texas and the 4-corners region, which should block the system's progress before it quite reaches the Texas coast. The shortwave trough may then dig in over the Great Lakes region and exert a northeastward tug on our gulf system, trying to pull it into Louisiana. It may succeed in doing this, and the GFS shows a similar solution by bringing a storm into the Florida Panhandle, but I think this may be overdone due to the typical GFS bias of strengthening troughs too much over the eastern seaboard this season. Chances are that our system will stall out for a while over the NW gulf and then eventually find a way to the north gulf coast, closer to the ECMWF solution.

Overall, what we're hoping for here is a weak Lee to develop and bring Texas some rain. Chances are that even if the storm moves into Louisiana, given its location of development, it is likely to give at least a few showers to coastal Texas anyway. The bad news is that the pattern favors it having to sit down there for a while over very hot water, and that could turn it into a potent system if atmospheric conditions allow. We'll have to monitor it closely, as home-grown development in the western gulf is notorious for meaning business. The central gulf coast all the way down to northern Mexico should keep an eye on this system this weekend and next week.

Tropical Storm Katia continues to chug along WNW. Dry air is present from the north to the west of the system, but she seems to be doing a good job keeping it out of her core. I have no big issues with the NHC forecast here, and Katia should be a major hurricane early next week in the central Atlantic north of the Antilles islands. I feel pretty confident that she will avoid the Antilles due to a weakness in the Bermuda High ahead of Katia which is great news for the islands. While she's still a long way out, I'm leaning towards the idea that she will miss the U.S. and recurve out to sea a bit west of Bermuda. The models are targeting Bermuda strongly today, and although I think they will shift a bit west eventually, Bermuda may need to keep a very close eye on this storm for early next week.

We shall see what happens!

Official NHC Forecast for Tropical Storm Katia:



Tropical Storm Katia Model Track Forecasts:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity Potential (green areas represent upward motion associated with the MJO):






Updated: 4:56 PM GMT on August 31, 2011

Permalink

Mischief in the gulf, possibly becoming Lee and hanging around; Katia chugs on

By: Levi32, 4:35 PM GMT on August 30, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



While we're all focused on Katia out east, we may have home-grown mischief in the Gulf of Mexico starting this weekend that may affect land before Katia is ever a threat. Thus, we will speak of it first, because I always consider the threats to land to be the highest priority. A tropical wave, or what I think is a tropical wave, is moving NW through the NW Caribbean. The NHC doesn't have it analyzed as a tropical wave, but we'll see if they throw it up there once they latch on to its development potential. This wave is moving NW towards a frontal boundary strung out over the Gulf of Mexico. This kind of a situation always argues for trouble, as the interaction between the wave and the front is a classic setup for home-grown mischief. Any development will be slow to occur, and we may not be talking about a concrete low pressure area until this weekend. The GFS and Euro both develop it into Lee eventually, which is evidence enough to watch it closely. Although development will be gradual due to the large area of energy involved, this system should have no competition from the eastern Pacific, because the monsoon trough is very far to the north over central America, so no development will be occurring in the EPAC for a while. This is directly related to how warm the SW Atlantic is, pulling the monsoon trough north and helping itself with development.

The track of any system that develops in the gulf will be northwest initially, as a shortwave trough moving into the Pacific Northwest today will be inducing a slight weakness in the ridge over Texas in 3-4 days, allowing the wave to make an approach to the northwest gulf coast. The ridge will try to hang tough however, and thus a direct move into Texas may be difficult. At this point by Saturday, the system could just scoot west under the ridge into south Texas and northern Mexico, or it could get caught in weak steering currents and sit around a while, because eventually the shortwave will move east and start tugging on the wave from the northeast, trying to bring it northeastward into the Louisiana area. These two tugs in opposite directions could result in our system hanging out for several days before finally going somewhere. This would be bad news if it is developing, as it would have lots of time over the 31C waters of the Gulf of Mexico.

Overall, this could be a wonderful rain event for Texas, so chances are we will be cheering on the development of Lee, but the Gulf is also very hot, and there have been many systems in the past that spun up ridiculously fast near the Texas coast, so we may need to keep an eye on this one if it develops. Again, development will be gradual, so it is of no immediate concern, and the issue will be more pressing this weekend. I do think we have a decent chance to see a storm out of this feature due to the setup.

Tropical Storm Katia continues to move WNW to even NW in the eastern Atlantic, gaining lots of latitude right now. This is good news for the northern Antilles Islands, though they may still need to keep a wary eye on her as she comes westward. The models already made a shift west, closer to my idea of where she'll be in 5-6 days. We'll see if that continues. My gut feeling is that her most likely path is up and out between Cape Hatteras and Bermuda, but as described yesterday, there is room in this pattern to get her farther west than that and threaten the United States. It's too far out to say for sure whether we are safe from Katia. She'll likely be a major hurricane by next week. We have lots of time to watch this storm, and she is no immediate threat to any land areas.

We shall see what happens!

Official NHC Forecast for Tropical Storm Katia:



Tropical Storm Katia Model Track Forecasts:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity Potential (green areas represent upward motion associated with the MJO):






Updated: 4:39 PM GMT on August 30, 2011

Permalink

TD 12 may or may not be an issue down the road; Texas may get rain 1st week of Sept.

By: Levi32, 5:03 PM GMT on August 29, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Tropical Storm Jose is gone, and that's all I have to say about that.

We will be watching the western Gulf of Mexico during the 3-10 day period for potential mischief, as an old frontal boundary over the northern gulf, along with a piece of mid-level energy, may try to amplify into an area of low pressure as time goes on. The models are all hinting at some kind of low pressure to develop and generate precipitation over the northwestern gulf. The great news about this is that, regardless of whether we get home-grown tropical mischief out of it, it has a good chance to bring some rain to Texas. The pattern is such that whenever a transient trough weakens the Texas ridge temporarily, the trough-split piece will try to move north into Texas, but then potentially get blocked as the ridge builds in again, forcing it back south towards the gulf. This could result in an area of disturbed weather remaining in the western gulf and Texas area for several days, which is great for rainfall potential if it pans out. We will have to monitor this area during the first week of September.

Tropical Depression #12 has formed SSW of the Cape Verde Islands. This will be moving WNW and will be named Katia, eventually becoming a hurricane, and perhaps a major. The models are likely too far north right off the bat with this system, as they almost always are with Cape Verde developments, especially in years like this. The GFS Day 8 forecast is already far too aggressive with the east coast trough, and its ensembles have a better solution. The ECMWF ensembles have also broken faith with the operational, showing what would be Katia 5-10 degrees farther south by Day 10. I show in the video how the pattern is still a very dangerous one, with ridging being dominant over southern Canada, tending to block recurves east of the U.S. if storms come in far enough south. The question here is whether this is going to be one of those rapidly-developing Cape Verde storms where it is inevitable that she turns out before reaching North America, or whether development will be gradual and the ridge will hold her far enough south to be a problem later. Right now I have a bet with the models that instead of being at 22N, 58W in 6-7 days like the consensus has her, I think she will be near 20N, 62W in about 6 days. This is still north of the Caribbean islands, and with the Azores high so far north it will be hard to allow TD 12 to affect the Caribbean, but the northeastern islands may have to keep an eye on her depending on how much latitude she gains in the coming days. For now, she's nearly a week out and not much of a concern yet.

Overall, with the system so far out right now, there are a few different possibilities, as always, and although it is very hard to get a rapidly-developing Cape Verde system all the way west to the United States, it is still a possibility in this dangerous pattern that we have been warning about for the peak of the hurricane season. We will be monitoring this storm closely as she develops. She is taking the place of the "Katrina" name on this year's list. Let's hope she isn't as fierce.

We shall see what happens!

Official NHC Forecast for Tropical Depression #12:



Tropical Depression #12 Model Track Forecasts:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity Potential (green areas represent upward motion associated with the MJO):






Permalink

Irene inland over New England; Watching for the next big storm from the east

By: Levi32, 3:40 PM GMT on August 28, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Irene is moving inland over New England and has been downgraded to a tropical storm of 60mph winds. The NHC didn't keep her at minimal hurricane intensity at landfall in western Long Island like they were forecasting before, but we will see if any wind reports come in to overturn that, as her pressure is still very low at 966mb. Damage reports are coming in and will continue today. Flooding seems to be the biggest issue, both from storm surge and from extremely heavy rainfall. Hopefully it ends up not being as bad and as costly as it could have been. This will definitely be a storm remember on the list of great storms that ran up the eastern seaboard. Interior New England and Maine still have to deal with the full force of Irene today and tonight, so hopefully people stay safe up there.

It will take quite a while to get over Irene in the northeast, and she will be talked about for a while, but we can now start finally moving on to new threats from the tropics. It is the peak of the hurricane season, and it's not going to let up after Irene.

Tropical Storm Jose has developed southwest of Bermuda, a complete waste of a name, and that really is true this time. The thing's already dead, and Bermuda probably won't even know it is there, although they are under a tropical storm warning.

A new tropical wave in the eastern Atlantic is forecasted to develop by all of the major models, and will likely become Katia. The ECMWF consistently develops the wave into a major hurricane in the southwest Atlantic in 10 days, with the most recent run putting it at 25N, 70W, a little too close to the U.S. for comfort, although it is already moving northwest by that time. The pattern for the next two weeks will consist of anomalous ridging over southeast Canada and the northern U.S., with the mean break between the Texas ridge and the Bermuda High sitting over the southeastern U.S. again, just as it did with Irene. This is the classic peak of the season pattern that we warned about, and it is capable of bringing storms into the Caribbean islands and U.S. if they come from far enough south. With our new wave, if it develops quickly and strengthens into a hurricane, it would be pretty hard to get it as far west as the islands or the U.S. before recurving, but it is a very long way out right now, and the pattern supports threats to the coast, so we will keep a close eye on it. Bermuda may have to eventually worry about it, but it is no cause for distress yet.

We shall see what happens!

Official NHC Forecast for Tropical Storm Irene:



Official NHC Public Advisory for Tropical Storm Irene:

000
WTNT34 KNHC 281457
TCPAT4

BULLETIN
TROPICAL STORM IRENE ADVISORY NUMBER 33
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 AM EDT SUN AUG 28 2011

...CENTER OF IRENE INLAND OVER SOUTHEASTERN NEW YORK STATE...
SOUTHERN NEW ENGLAND...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...41.4N 73.7W
ABOUT 10 MI...20 KM W OF DANBURY CONNECTICUT
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 26 MPH...43 KM/H
MINIMUM CENTRAL PRESSURE...966 MB...28.53 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE HURRICANE WARNING FROM CHINCOTEAGUE VIRGINIA TO SAGAMORE BEACH
MASSACHUSETTS IS CHANGED TO A TROPICAL STORM WARNING. ALL WARNINGS
HAVE BEEN DISCONTINUED ALONG THE ATLANTIC COAST SOUTH OF
CHINCOTEAGUE AND FOR CHESAPEAKE BAY SOUTH OF NORTH BEACH.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* CHINCOTEAGUE VIRGINIA NORTHWARD TO EASTPORT MAINE...
INCLUDING CHESAPEAKE BAY NORTH OF NORTH BEACH...DELAWARE BAY...NEW
YORK CITY...LONG ISLAND...LONG ISLAND SOUND...COASTAL CONNECTICUT
AND RHODE ISLAND...BLOCK ISLAND...MARTHAS VINEYARD AND NANTUCKET
* UNITED STATES/CANADA BORDER NORTHEASTWARD TO FORT LAWRENCE
INCLUDING GRAND MANAN
* SOUTH COAST OF NOVA SCOTIA FROM FORT LAWRENCE TO PORTERS LAKE

INTERESTS ELSEWHERE IN EASTERN CANADA SHOULD MONITOR THE PROGRESS OF
IRENE.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF TROPICAL STORM IRENE WAS
LOCATED NEAR LATITUDE 41.4 NORTH...LONGITUDE 73.7 WEST. IRENE IS
MOVING TOWARD THE NORTH-NORTHEAST NEAR 26 MPH...43 KM/H...AND THIS
MOTION WITH A LITTLE FASTER FORWARD SPEED IS EXPECTED OVER THE NEXT
DAY OR SO. ON THE FORECAST TRACK...THE CENTER OF IRENE WILL MOVE
OVER NORTHERN NEW ENGLAND LATER TODAY AND OVER EASTERN CANADA
TONIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/H...WITH HIGHER
GUSTS. IRENE IS FORECAST TO WEAKEN AND BECOME A POST-TROPICAL
CYCLONE BY TONIGHT.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 320 MILES...520 KM
FROM THE CENTER. A WEATHERFLOW STATION ON FIRE ISLAND RECENTLY
REPORTED SUSTAINED WINDS OF 50 MPH...80 KM/H...WITH A GUST TO 63
MPH...101 KM/H.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 966 MB...28.53 INCHES.
CENTRAL PARK IN NEW YORK CITY REPORTED 966.5 MB...28.54 AS THE
CENTER PASSED THIS MORNING.


HAZARDS AFFECTING LAND
----------------------
STORM SURGE...AN EXTREMELY DANGEROUS STORM SURGE WILL RAISE WATER
LEVELS BY AS MUCH AS 4 TO 8 FEET ABOVE GROUND LEVEL FROM WESTERN
PORTIONS OF LONG ISLAND ISLAND SOUND EASTWARD ALONG THE SOUTHERN
COASTS OF CONNECTICUT...RHODE ISLAND...AND MASSACHUSETTS. THE
HIGHEST SURGES WILL OCCUR NEAR THE UPPER PARTS OF BAYS AND INLETS.
NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE...
DESTRUCTIVE...AND LIFE-THREATENING WAVES. HIGHER THAN NORMAL
ASTRONOMICAL TIDES ARE OCCURRING THIS WEEKEND. COASTAL AND RIVER
FLOODING WILL BE HIGHEST IN AREAS WHERE THE PEAK SURGE OCCURS
AROUND THE TIME OF HIGH TIDE. STORM TIDE AND SURGE VALUES ARE VERY
LOCATION-SPECIFIC...AND USERS ARE URGED TO CONSULT PRODUCTS ISSUED
BY THEIR LOCAL NATIONAL WEATHER SERVICE OFFICES. WATER LEVELS
ALONG THE NEW JERSEY AND DELAWARE COAST INCLUDING DELAWARE BAY WILL
SUBSIDE TODAY.

RAINFALL...IRENE IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 4 TO 8 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF 12 INCHES...
FROM NORTHEASTERN PENNSYLVANIA AND NORTHERN NEW JERSEY NORTHWARD
INTO NEW YORK STATE AND INTERIOR NEW ENGLAND. THESE RAINS...
COMBINED WITH HEAVY RAINS OVER THE PAST FEW WEEKS...COULD
CAUSE WIDESPREAD FLOODING...LIFE-THREATENING FLASH FLOODS...AND
SIGNIFICANT UPROOTING OF TREES DUE TO RAIN-SOFTENED GROUNDS.

WIND...TROPICAL STORM FORCE WINDS WILL SPREAD NORTHWARD INTO
NORTHERN NEW ENGLAND AND ATLANTIC CANADA TODAY. WINDS AFFECTING
THE UPPER FLOORS OF HIGH-RISE BUILDINGS COULD BE SIGNIFICANTLY
STRONGER THAN THOSE NEAR GROUND LEVEL.

TORNADOES...ISOLATED TORNADOES ARE POSSIBLE OVER SOUTHERN NEW
ENGLAND THIS AFTERNOON.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM EDT.
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER PASCH/BLAKE

Invest 92L Model Track Forecasts:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity Potential (green areas represent upward motion associated with the MJO):






Updated: 4:05 PM GMT on August 28, 2011

Permalink

Irene leaving North Carolina flooded - continuing up the mid-Atlantic coast

By: Levi32, 2:34 PM GMT on August 27, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook

Special Saturday Evening Update as of 10pm EDT for Hurricane Irene:

I apologize for the echoing and for my rather unorganized presentation in tonight's video. I am getting very tired, as I have had very little sleep during Irene's landfall.



Hurricane Irene remains a Cat 1 hurricane with 80mph sustained winds. Irene has exited northeast North Carolina, and now sits over the water east of Maryland. After filling up with precipitation earlier, a small eye feature has reappeared, though this is not really a sign of intensification. Waters are a lot colder up here outside of the Gulf Stream, and Irene is in a stage where she should very slowly weaken as she moves into New England. A buoy just off the coast of North Carolina measured a pressure of 950.6mb with 60kt winds, later confirmed by recon. This is the same pressure that Irene had 30 hours ago north of the Bahamas, and it is absolutely insane that after all she has been through with losing her eye and then spending 10 hours over land, that she should still be maintaining the same intensity without weakening. By all appearances on satellite and radar, she should be weakening, but she is not. The maximum winds I can find so far reported on land were at Cedar Island, North Carolina, which reported sustained winds of 90mph with a gust to 115mph earlier this afternoon. This was an isolated event, and peak winds elsewhere have been along the lines of sustained 80mph and gusts near 100mph.

Irene's pressure is characteristic of a strong Cat 3, and if she still had an eye, we would likely see at least Cat 2 winds with this storm, and thus North Carolina got off very very lucky. The low pressure means that all of that energy is just spread out over a very large area, and Irene has a swatch of maximum winds that is over 100 miles wide. It's like having a gigantic but weak eyewall. This is bad for many people because we're talking about over 18 hours of sustained tropical storm force winds for most folks up the eastern seaboard, with several hours of hurricane force gusts.

Rainfall has exceeded 10 inches in many places in North Carolina and Virginia, and amounts of over 5 inches estimated by radar extend all the way up into New Jersey already. The ground was already saturated, and flash floods and river flooding will be one of Irene's biggest problems for the northeast U.S. during the next 36 hours. Storm surges of 4-8ft into the area from Virginia Beach all the way to Cape Cod will also be damaging, and with 25ft waves being reported offshore on top of the surge, the ocean may breach the Long Island seawall, especially since the surge will arrive near high tide. Water damage may be the worst that Irene has to offer, but wind damage could still be substantial in the big cities, especially New York, as tall city buildings will reach up into higher winds off the ground and experience high stresses.

Overall, this IS a historic storm, and most of New England's historic storms have been absolutely no stronger than Irene. Remember that. She will weaken only slowly, and with a central pressure of 951mb, she will likely remain at hurricane strength before hitting western Long Island tomorrow morning. Please be safe everyone! I will have another update tomorrow morning.

We shall see what happens!

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~

Saturday Morning Update:




Hurricane Irene made landfall near Cape Lookout, North Carolina at 7:30am EDT this morning. Irene did not strengthen yesterday due to dry air issues eating her core, and the lack of an eyewall meant that the strongest winds possible in this storm did not get a chance to develop, despite the fact that Irene's central pressure of 952mb supports a strong Cat 3. Her winds in reality are of Category 1 nature, and thus North Carolina is getting off very lucky today. We could have very easily had a major hurricane making landfall this morning. However, it is far from over. 10 inches of rain have already fallen in places according to radar estimates out of Morehead City, and the large circulation of Irene means that tropical storm force winds will be over the region for some time. Irene will be moving up the coast of the mid-Atlantic states and will be extraordinarily slow to weaken. Her extremely low pressure and large size means that it will take a ton of air to finally fill her up to the point where she will only be a tropical storm. The NHC has her as a hurricane all the way up to Connecticut, and I agree with this forecast. A strong jetstream north of New England will be baroclinically influencing the area and helping pressures to remain low, and this storm will be a big deal all the way up the coast.

The storm surge and rainfall will likely be bigger issues than the wind with Irene, but her wind field is so large that many areas will get prolonged exposure to 60mph or higher winds and gusts all along the eastern seaboard, and that can cause some stresses and damage more than if we were dealing with a smaller storm. The size of Irene also means she is carrying a storm surge typical of a Cat 3 instead of a Cat 1. Again, Irene is acting like a Cat 3 in every way except for her sustained winds, and the only reason those aren't Cat 3 strength is because she has had no eyewall since yesterday. Rainfall will be 6-10 inches with isolated higher amounts in a swath all the way up the coast of the mid-Atlantic and up into interior New England. The heaviest rains will be in the NW quadrant of the storm due to baroclinic influences, similar in many ways to a nor'easter in terms of the precipitation maximums. This will cause inland flooding issues along with the coastal flooding that is sure to be caused by the storm surge of 4-8ft from Virginia to Cape Cod.

We hope and pray that folks in North Carolina are alright and that property damages are not too bad. They have gone through this before and will hopefully pull through again. Farther up the coast, this is not the case, and folks are not used to hurricanes in their back yard. New York is taking this storm very seriously for a good reason. Hopefully damages will be less than expected, but this is going to be a very bad storm for New England and the mid-Atlantic today and tomorrow.

I may have another update this evening.

We shall see what happens!

Official NHC Forecast for Hurricane Irene:



Official NHC Public Advisory for Hurricane Irene:

000
WTNT34 KNHC 280053
TCPAT4

BULLETIN
HURRICANE IRENE INTERMEDIATE ADVISORY NUMBER 30B
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
900 PM EDT SAT AUG 27 2011

...IRENE LASHING THE VIRGINIA TIDEWATER REGION AND SOUTHERN DELMARVA
PENINSULA WITH HEAVY RAINS AND HURRICANE-FORCE WIND GUSTS...


SUMMARY OF 900 PM EDT...0100 UTC...INFORMATION
----------------------------------------------
LOCATION...36.9N 75.6W
ABOUT 100 MI...160 KM SSW OF OCEAN CITY MARYLAND
ABOUT 285 MI...460 KM SSW OF NEW YORK CITY
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...951 MB...28.08 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE HURRICANE WARNING HAS BEEN DISCONTINUED SOUTH OF CAPE LOOKOUT
NORTH CAROLINA.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* CAPE LOOKOUT NORTH CAROLINA NORTHWARD TO SAGAMORE BEACH
MASSACHUSETTS...INCLUDING THE PAMLICO...ALBEMARLE...AND CURRITUCK
SOUNDS...DELAWARE BAY...CHESAPEAKE BAY SOUTH OF DRUM POINT...NEW
YORK CITY...LONG ISLAND...LONG ISLAND SOUND...COASTAL CONNECTICUT
AND RHODE ISLAND...BLOCK ISLAND...MARTHAS VINEYARD AND NANTUCKET

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* CHESAPEAKE BAY FROM DRUM POINT NORTHWARD AND THE TIDAL POTOMAC
* NORTH OF SAGAMORE BEACH TO EASTPORT MAINE
* UNITED STATES/CANADA BORDER NORTHEASTWARD TO FORT LAWRENCE
INCLUDING GRAND MANAN
* SOUTH COAST OF NOVA SCOTIA FROM FORT LAWRENCE TO PORTERS LAKE

INTERESTS ELSEWHERE IN EASTERN CANADA SHOULD MONITOR THE PROGRESS OF
IRENE.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 900 PM EDT...0100 UTC...THE CENTER OF HURRICANE IRENE WAS LOCATED
NEAR LATITUDE 36.9 NORTH...LONGITUDE 75.6 WEST. IRENE IS MOVING
TOWARD THE NORTH-NORTHEAST NEAR 16 MPH...26 KM/H...AND THIS MOTION
ACCOMPANIED BY A GRADUAL INCREASE IN FORWARD SPEED IS EXPECTED
DURING THE NEXT DAY OR SO. ON THE FORECAST TRACK...THE CENTER OF
IRENE WILL MOVE NEAR OR OVER THE MID-ATLANTIC COAST TONIGHT...AND
MOVE OVER SOUTHERN NEW ENGLAND ON SUNDAY. IRENE IS FORECAST TO MOVE
INTO EASTERN CANADA SUNDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 80 MPH...130 KM/H...WITH HIGHER
GUSTS. IRENE IS FORECAST TO REMAIN A HURRICANE AS IT MOVES NEAR OR
OVER THE MID-ATLANTIC COAST AND APPROACHES NEW ENGLAND. THE
HURRICANE IS FORECAST TO WEAKEN AFTER LANDFALL IN NEW ENGLAND AND
BECOME A POST-TROPICAL CYCLONE SUNDAY NIGHT OR EARLY MONDAY.

IRENE IS A LARGE TROPICAL CYCLONE. HURRICANE-FORCE WINDS EXTEND
OUTWARD UP TO 85 MILES...140 KM...FROM THE CENTER...AND
TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 290 MILES...465 KM.
A WIND GUST TO 76 MPH WAS RECENTLY REPORTED AT THE WILLIAMSBURG-
JAMESTOWN VIRGINIA AIRPORT. TROPICAL STORM CONDITIONS WILL
GRADUALLY SPREAD NORTHWARD INTO NORTHERN PORTIONS OF THE DELMARVA
PENINSULA AND SOUTHERN NEW JERSEY.

A STORM SURGE HEIGHT OF ABOUT 5 FEET HAS BEEN OBSERVED AT OREGON
INLET NORTH CAROLINA...AND A STORM SURGE HEIGHT OF ABOUT 4 FEET
HAS OCCURRED THUS FAR AT THE MOUTH OF THE CHESAPEAKE BAY. THE
PRELIMINARY WATER LEVEL AT THE CHESAPEAKE BAY BRIDGE TUNNEL HAS
RECENTLY PEAKED NEAR THE RECORD LEVEL THAT WAS ESTABLISHED DURING
HURRICANE ISABEL IN 2003.

RAINFALL AMOUNTS OF 10 TO 14 INCHES HAVE ALREADY OCCURRED OVER A
LARGE PORTION OF EASTERN NORTH CAROLINA AND EXTREME SOUTHEASTERN
VIRGINIA...WITH THE HIGHEST AMOUNT OF 14.00 INCHES REPORTED AT
BUNYAN NORTH CAROLINA THUS FAR.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 951 MB...28.08 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL-STORM-FORCE WINDS WILL CONTINUE SPREAD NORTHWARD
ALONG THE MID-ATLANTIC COAST THIS EVENING WITH HURRICANE CONDITIONS
EXPECTED TONIGHT. TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH
SOUTHERN NEW ENGLAND LATE THIS EVENING WITH HURRICANE CONDITIONS
EXPECTED BY SUNDAY MORNING. WINDS AFFECTING THE UPPER FLOORS OF
HIGH-RISE BUILDINGS WILL BE SIGNIFICANTLY STRONGER THAN THOSE NEAR
GROUND-LEVEL.

STORM SURGE...AN EXTREMELY DANGEROUS STORM TIDE WILL RAISE WATER
LEVELS BY AS MUCH AS 5 TO 9 FEET ABOVE GROUND LEVEL IN THE
HURRICANE WARNING AREA IN NORTH CAROLINA...INCLUDING THE ALBEMARLE
AND PAMLICO SOUNDS. STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH
AS 4 TO 8 FEET ABOVE GROUND LEVEL WITHIN THE HURRICANE WARNING AREA
FROM THE NORTH CAROLINA/VIRGINIA BORDER NORTHWARD TO CAPE COD
INCLUDING SOUTHERN PORTIONS OF THE CHESAPEAKE BAY AND ITS
TRIBUTARIES. NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY
LARGE...DESTRUCTIVE...AND LIFE-THREATENING WAVES. HIGHER THAN
NORMAL ASTRONOMICAL TIDES ARE OCCURRING THIS WEEKEND. COASTAL AND
RIVER FLOODING WILL BE HIGHEST IN AREAS WHERE THE PEAK SURGE OCCURS
AROUND THE TIME OF HIGH TIDE. STORM TIDE AND SURGE VALUES ARE VERY
LOCATION-SPECIFIC...AND USERS ARE URGED TO CONSULT PRODUCTS ISSUED
BY THEIR LOCAL NATIONAL WEATHER SERVICE OFFICES.

RAINFALL...IRENE IS EXPECTED TO PRODUCE RAINFALL ACCUMULATIONS OF
6 TO 12 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF 20 INCHES...FROM
EASTERN NORTH CAROLINA NORTHWARD THROUGH THE MID-ATLANTIC STATES
INTO EASTERN NEW YORK AND INTERIOR NEW ENGLAND. THESE RAINS...
COMBINED WITH HEAVY RAINS OVER THE PAST FEW WEEKS...COULD CAUSE
WIDESPREAD FLOODING...LIFE-THREATENING FLASH FLOODS...AND
SIGNIFICANT UPROOTING OF TREES DUE TO RAIN-SOFTENED GROUNDS.

SURF...LARGE SWELLS GENERATED BY IRENE ARE AFFECTING MUCH OF THE
EAST COAST OF THE UNITED STATES. THESE SWELLS WILL CAUSE
LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS.

TORNADOES...ISOLATED TORNADOES ARE POSSIBLE ALONG THE COAST OF
MARYLAND...DELAWARE...AND NEW JERSEY THROUGH TONIGHT.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 PM EDT.

$$
FORECASTER STEWART/BERG


Norfolk, VA Radar Loop:



Dover AFB, Delaware Radar Loop:



Hurricane Storm Irene Visible/IR2 Floater:



Hurricane Irene Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity Potential (green areas represent upward motion associated with the MJO):






Updated: 2:22 AM GMT on August 28, 2011

Permalink

Irene remains very powerful - moving towards North Carolina

By: Levi32, 1:03 PM GMT on August 26, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Hurricane Irene continues to move towards the United States this morning. After staying rock solid at 943mb all night, the pressure just this last hour rose to 947mb, a significant rise in a 1 hour period, indicating some weakening taking place. We may see some more rises in the pressure to above 950mb before it levels off again. The SW quad of the storm almost doesn't exist, and the core is fully open there, including the eyewall, which never got to fully close off after the eyewall replacement cycle tried to complete yesterday. Dry air entrainment off of North America is very evident into the west and south sides of the circulation, something that we talked about would try to weaken Irene as she moved towards North Carolina. Outflow remains beautiful everywhere but the southwest quad, with a 90kt outflow jet east of the storm, absolutely amazing to see.

The NHC downgraded Irene to a Cat 2 storm, despite a pressure in the 940s, which normally supports nearly a Cat 4. This is due to Irene's very large size, spreading out the pressure gradient. The NHC forecasts Irene to strengthen back into a Cat 3 before landfall in North Carolina. I actually agree, because my forecast was for a Cat 4 yesterday and today and then weakening to a low Cat 3 before landfall. Irene hasn't given me the Cat 4 winds, but she has actually given me the pressure during her strengthening yesterday. Her core can't look much worse with the dry air, and thus there's really only room for improvement. Tightening of the core may occur before landfall, and the GFDL and HWRF 06z runs actually foretold the weakening during today that is starting now with the recent pressure rise. I show this in the video. They then restrengthen the core at landfall back into a Cat 3 wind field after weakening the winds to Cat 1 strength. This is interesting, and very possible, especially since the global models agree on deepening before landfall in North Carolina. For that reason, I still forecast a Cat 3 Irene when she hits the outer banks.

The track philosophy remains identical. A shortwave is leaving the northeast, about to be followed by another one over southern Canada which will be the last in the series, and will be the one to fully recurve her. This recurve will occur just over the outer banks of North Carolina, and then up just east of the New Jersey coast, and into Long Island. I've had this track since Wednesday, and in general it agrees with the latest NHC forecast. We've ceased the large shifts now, and only minor adjustments of a couple dozen miles will occur before final landfall in New England or the mid-Atlantic. The immense size of the storm means that the exact location of the eye only really affects the storm surge, which should be bad regardless in the Long Island area. Irene should be weakening below Cat 2 status by the time she makes it to Long Island, but Cat 1 winds can do a lot of damage, especially with rain-soaked ground not holding their trees very well. The storm surge will be that of a Cat 3 regardless of how weak Irene is by the time she moves into New England. Even without the wind and surge, over 10 inches of rain is expected to fall in New Jersey and up through the entire mid-Atlantic and New England, on top of an already record month of rain. This will cause massive flooding issues on top of everything else. Hopefully everyone is prepared for this potentially historic event, which is no exaggeration.

We shall see what happens!


Official NHC Forecast for Hurricane Irene:



Official NHC Public Advisory for Hurricane Irene:

000
WTNT34 KNHC 261156
TCPAT4

BULLETIN
HURRICANE IRENE INTERMEDIATE ADVISORY NUMBER 24A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
800 AM EDT FRI AUG 26 2011

...IRENE TAKING AIM AT THE EAST COAST OF THE UNITED STATES...


SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...30.0N 77.3W
ABOUT 375 MI...600 KM SSW OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...945 MB...27.91 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

NONE

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* THE GRAND BAHAMA AND THE ABACO ISLANDS
* LITTLE RIVER INLET NORTH CAROLINA NORTHWARD TO SANDY HOOK NEW
JERSEY...INCLUDING THE PAMLICO...ALBEMARLE...AND CURRITUCK
SOUNDS...DELAWARE BAY...AND CHESAPEAKE BAY SOUTH OF SMITH POINT.

A HURRICANE WATCH IS IN EFFECT FOR...
* NORTH OF SANDY HOOK NEW JERSEY TO THE MOUTH OF THE MERRIMACK RIVER
MASSACHUSETTS...INCLUDING NEW YORK CITY...LONG ISLAND...LONG ISLAND
SOUND...BLOCK ISLAND...BOSTON...MARTHAS VINEYARD AND NANTUCKET.

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* NORTH OF EDISTO BEACH SOUTH CAROLINA TO LITTLE RIVER INLET
* CHESAPEAKE BAY FROM SMITH POINT NORTHWARD AND THE TIDAL POTOMAC

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA. A WARNING IS TYPICALLY ISSUED
36 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF
TROPICAL-STORM-FORCE WINDS...CONDITIONS THAT MAKE OUTSIDE
PREPARATIONS DIFFICULT OR DANGEROUS. PREPARATIONS TO PROTECT LIFE
AND PROPERTY SHOULD BE RUSHED TO COMPLETION.

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA. A WATCH IS TYPICALLY ISSUED 48 HOURS
BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-FORCE
WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR
DANGEROUS.

INTERESTS ELSEWHERE IN NEW ENGLAND SHOULD MONITOR THE PROGRESS OF
IRENE.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 AM EDT...1200 UTC...THE CENTER OF HURRICANE IRENE WAS LOCATED
NEAR LATITUDE 30.0 NORTH...LONGITUDE 77.3 WEST. IRENE IS MOVING
TOWARD THE NORTH NEAR 14 MPH...22 KM/H...AND THIS MOTION IS
EXPECTED TO CONTINUE DURING THE NEXT 24 HOURS. A GRADUAL TURN
TOWARD THE NORTH-NORTHEAST SHOULD BEGIN THEREAFTER. ON THE
FORECAST TRACK...THE CORE OF THE HURRICANE WILL PASS WELL OFF THE
COAST OF NORTHEASTERN FLORIDA TODAY...APPROACH THE COAST OF NORTH
CAROLINA TONIGHT...AND PASS NEAR OR OVER THE NORTH CAROLINA COAST
SATURDAY. THE HURRICANE IS FORECAST TO MOVE NEAR OR OVER THE
MID-ATLANTIC COAST SATURDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 110 MPH...175 KM/H...WITH
HIGHER GUSTS. IRENE IS A CATEGORY TWO HURRICANE ON THE
SAFFIR-SIMPSON HURRICANE WIND SCALE. SOME RE-INTENSIFICATION IS
POSSIBLE TODAY...AND IRENE IS EXPECTED TO BE NEAR THE THRESHOLD
BETWEEN CATEGORY TWO AND THREE AS IT REACHES THE NORTH CAROLINA
COAST.

IRENE IS A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS EXTEND
OUTWARD UP TO 90 MILES...150 KM...FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 290 MILES...465 KM.

THE MINIMUM CENTRAL PRESSURE ESTIMATED FROM HURRICANE HUNTER
AIRCRAFT DATA IS 945 MB...27.91 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...WINDS WILL SUBSIDE OVER THE NORTHWESTERN BAHAMAS THIS
MORNING. TROPICAL STORM FORCE WINDS ARE EXPECTED WITHIN THE
SOUTHERN PORTION OF THE WARNING AREA ALONG THE UNITED STATES EAST
COAST BY LATE TODAY. HURRICANE FORCE WINDS ARE EXPECTED TO FIRST
REACH THE HURRICANE WARNING AREA TONIGHT OR SATURDAY MORNING...AND
THEN SPREAD NORTHWARD IN THE WARNING AREA THROUGH SATURDAY NIGHT.

STORM SURGE...AN EXTREMELY DANGEROUS STORM SURGE WILL RAISE WATER
LEVELS BY AS MUCH AS 6 TO 11 FEET ABOVE GROUND LEVEL IN THE
HURRICANE WARNING AREA IN NORTH CAROLINA...INCLUDING THE ALBEMARLE
AND PAMLICO SOUNDS. STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH
AS 4 TO 8 FEET ABOVE GROUND LEVEL OVER SOUTHERN POTIONS OF THE
CHESAPEAKE BAY...INCLUDING TRIBUTARIES...AND THE EASTERN SHORE OF
THE DELMARVA PENINSULA. STORM SURGE WILL RAISE WATER LEVELS BY AS
MUCH AS 3 TO 6 FEET ABOVE GROUND LEVEL ALONG THE JERSEY SHORE.
NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE...
DESTRUCTIVE...AND LIFE-THREATENING WAVES.

RAINFALL...IRENE IS EXPECTED TO PRODUCE RAINFALL ACCUMULATIONS OF
6 TO 10 INCHES...WITH ISOLATED MAXIMUM AMOUNTS OF 15 INCHES...FROM
EASTERN NORTH CAROLINA INTO SOUTHEASTERN VIRGINA...EASTERN
MARYLAND... DELAWARE...EASTERN PENNSYLVANIA...NEW JERSEY...
SOUTHEASTERN NEW YORK...LONG ISLAND...WESTERN CONNECTICUT...AND
WESTERN MASSACHUSETTS THROUGH MONDAY MORNING. THESE RAINS COULD
CAUSE WIDESPREAD FLOODING AND LIFE-THREATENING FLASH FLOODS.

SURF...LARGE SWELLS GENERATED BY IRENE ARE AFFECTING PORTIONS
OF THE COAST OF THE SOUTHEASTERN UNITED STATES. THESE SWELLS WILL
CAUSE LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 AM EDT.

$$
FORECASTER BROWN


Morehead City, NC Radar Loop:



Hurricane Storm Irene Visible/IR2 Floater:



Hurricane Irene Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity Potential (green areas represent upward motion associated with the MJO):






Updated: 1:22 PM GMT on August 26, 2011

Permalink

Irene likely to hit North Carolina as a major hurricane and slam the NE U.S.

By: Levi32, 4:09 PM GMT on August 25, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Hurricane Irene remains a Category 3, and is absolutely pummeling the Bahamas right now, with the eyewall now moving over Abaco Island. According to the NHC, Nassau had an unofficial report of a wind gust to 100mph overnight. They may have avoided the main eyewall, but the northwestern Bahamas are getting nailed. Irene's eye is not as apparent on visible satellite imagery as it was yesterday, and is clouded over. Irene was going through an Eye-Wall Replacement Cycle (EWRC) last night, but this morning there is no double eyewall structure according to the recon planes. It is hard to tell whether the EWRC completed, or whether the outer eyewall disintegrated and the old one has taken over again. Either way, a single eyewall structure should again allow Irene to strengthen and the eye to clear out a bit more later today and tonight. The NHC has backed off on her peak intensity, keeping her only as high as 125mph, but I still think a low Cat 4 is likely to be her peak. Irene is likely to be a Category 3 at landfall in North Carolina, near the outer banks, and mandatory evacuations have already gotten underway there. The ECMWF has consistently put Irene into the 920-930mb range at landfall in NC, which is concerning, and thus the possibility of Irene even being a Cat 4 at landfall cannot be ruled out, though I suspect the Euro is a bit overdone here. However, it is only the 2nd time I have ever seen the ECMWF show an Atlantic hurricane this strong, and the last time was last year with Hurricane Igor, which fell just shy of Category 5.

My track from yesterday, after having to shift east, seems to look good today, as the models have come back west towards me this time. The reasoning for the track hugging the coast is explained in the video. In short, the shortwave recurving Irene will be pretty far north over Canada, and high heights east of New England will steer Irene north. This overall pattern has been setup for a very long time as one that should bring a storm into the eastern seaboard if one formed, and we are seeing that manifested now in a storm that could go down as one of the great east coast hurricanes of our time. It's not every day that the NHC has a Category 2 hurricane over southeast Maryland, as the 11am forecast does this morning. Hurricane force winds will be impacting Atlantic City, New Jersey and New York City along this path, with tropical storm force winds extending out to Washington D.C., Baltimore, Philadelphia, and Boston. Dozens of millions of people live in these areas, and thus even a weakening storm will wreak havoc. The global models have been very bullish at maintaining the storm's intensity as it moves up the coast, despite significantly colder water temperatures off of Long Island. Some of this has to do with the storm's size, but also the overall environment and how it's phasing with the jetstream, which favors the storm maintaining hurricane intensity for an abnormally long time.

Overall, Irene is a potentially historic storm for the eastern seaboard of the U.S., and as the Bahamas get their final lashing from the storm today, folks here should be preparing for this angry lady as she prepares to ride right up the population centers of the mid-Atlantic states and New England.

We shall see what happens!



Official NHC Forecast for Hurricane Irene:



Official NHC Public Advisory for Hurricane Irene:

000
WTNT34 KNHC 251454
TCPAT4

BULLETIN
HURRICANE IRENE ADVISORY NUMBER 21
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 AM EDT THU AUG 25 2011

...DANGEROUS HURRICANE IRENE TURNS NORTH-NORTHWESTWARD...CORE
APPROACHING ABACO ISLAND...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...25.9N 76.8W
ABOUT 75 MI...115 KM NNE OF NASSAU
ABOUT 645 MI...1040 KM S OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...NNW OR 335 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...951 MB...28.08 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

NONE

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* THE CENTRAL AND NORTHWESTERN BAHAMAS

A HURRICANE WATCH IS IN EFFECT FOR...
* NORTH OF SURF CITY NORTH CAROLINA TO THE NORTH CAROLINA-VIRGINIA
BORDER INCLUDING THE PAMLICO...ALBEMARLE...AND CURRITUCK SOUNDS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* NORTH OF EDISTO BEACH SOUTH CAROLINA TO SURF CITY NORTH CAROLINA

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA. A WATCH IS TYPICALLY ISSUED 48 HOURS
BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-FORCE
WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR
DANGEROUS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

WARNINGS WILL LIKELY BE REQUIRED FOR PORTIONS OF THE WATCH AREA
LATER TODAY. THE HURRICANE WATCH WILL ALSO LIKELY NEED TO BE
EXTENDED NORTHWARD ALONG THE MID-ATLANTIC COAST LATER TODAY.
INTERESTS ELSEWHERE IN THE MID-ATLANTIC STATES AND NEW ENGLAND
SHOULD MONITOR THE PROGRESS OF IRENE.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF HURRICANE IRENE WAS
LOCATED NEAR LATITUDE 25.9 NORTH...LONGITUDE 76.8 WEST. IRENE IS
MOVING TOWARD THE NORTH-NORTHWEST NEAR 13 MPH...20 KM/H. THIS
MOTION IS EXPECTED TO CONTINUE THROUGH TONIGHT WITH A TURN TOWARD
THE NORTH BY EARLY FRIDAY. ON THE FORECAST TRACK...THE CORE OF THE
HURRICANE WILL CONTINUE TO MOVE OVER THE NORTHWESTERN BAHAMAS
TODAY...AND PASS WELL OFFSHORE OF THE EAST COAST OF CENTRAL AND
NORTH FLORIDA TONIGHT AND EARLY FRIDAY. THE HURRICANE IS FORECAST
TO APPROACH THE COAST OF NORTH CAROLINA ON SATURDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 115 MPH...185 KM/H...WITH HIGHER
GUSTS. IRENE IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME STRENGTHENING IS POSSIBLE TODAY AND
TONIGHT.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 290
MILES...465 KM.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT WAS 951 MB...28.08 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...HURRICANE FORCE WINDS ARE CURRENTLY SPREADING OVER THE
NORTHWESTERN BAHAMAS. HURRICANE OR TROPICAL STORM FORCE WINDS ARE
STILL OCCURRING OVER PORTIONS OF THE CENTRAL BAHAMAS...BUT SHOULD
BEGIN TO DIMINISH LATER TODAY. TROPICAL STORM FORCE WINDS ARE
POSSIBLE WITHIN THE WATCH AREA ALONG THE COAST OF NORTH AND SOUTH
CAROLINA BY LATE FRIDAY.

STORM SURGE...IN AREAS OF ONSHORE WINDS NEAR THE CENTER OF IRENE...
AN EXTREMELY DANGEROUS STORM SURGE WILL RAISE WATER LEVELS BY AS
MUCH AS 7 TO 11 FEET ABOVE NORMAL TIDE LEVELS OVER THE CENTRAL AND
NORTHWEST BAHAMAS. WATER LEVELS WILL GRADUALLY SUBSIDE OVER THE
SOUTHEASTERN BAHAMAS THROUGH TONIGHT. NEAR THE COAST...THE SURGE
WILL BE ACCOMPANIED BY LARGE AND DANGEROUS WAVES.

RAINFALL...IRENE IS EXPECTED TO PRODUCE RAINFALL ACCUMULATIONS OF 6
TO 12 INCHES OVER THE BAHAMAS.

SURF...SWELLS GENERATED BY IRENE ARE AFFECTING PORTIONS OF THE COAST
OF THE SOUTHEASTERN UNITED STATES. THESE SWELLS WILL CAUSE
LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS. PLEASE CONSULT
PRODUCTS FROM YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM EDT.
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BROWN


Hurricane Storm Irene Visible/IR2 Floater:



Hurricane Irene Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

Irene slamming the Bahamas, may scrap the outer banks, possibly to hit New England

By: Levi32, 3:59 PM GMT on August 24, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Irene is now a major hurricane, roaring through the southeastern Bahamas. We talked about the potential for a major hurricane to be threatening this area, and here it is. The eye has started to clear out, and although recon is still reporting a periodically open eyewall, the storm is strengthening, with a central pressure down to 957mb. The eye is moving directly over Acklins Island right now, and folks down in the Bahamas are getting pounded by Irene's worst. The track will be taking Irene just east of Nassau, the capital, which holds 70% of the Bahamas' total population. Folks there should be prepared for the possibility of at least a glancing hit from Irene's eye, which could bring a couple categories of hurricane force winds to that city, depending on how close she passes to the island.

My intensity forecast for Irene remains the same as yesterday. She should reach a peak of a low Cat 4, which is now reflected by the latest NHC forecast. A weakening to a low-end Cat 3 or high Cat 2 should occur as she brushes the outer banks of North Carolina, due to dry air entrainment and some shearing from an upper trough west of her. After that, we could see a Category 1 or even a Category 2 approaching New England as Irene continues NNE. The NHC has Irene still at Cat 2 intensity east of Delaware Bay. This would be a very bad disaster for New England if this intensity and track come true. Folks up there are not used to hurricanes, but should be making some preparations.

The track forecast philosophy really hasn't changed, though the track continues to inch eastward. This is good news, as we could now be talking about Irene largely sparing North Carolina, but they are not out of the woods yet, especially the outer banks. Folks along the NC coastline should not keep their eyes off of this storm until they see it physically passing east of them. Preparations need to be completed soon for this storm. Some models now take Irene east of Cape Cod as well, avoiding New England, but the consensus is still over eastern Long Island and into the Boston area. This is one of the most densely populated regions in the country, and even a Cat 1 up here would be devastating. There is hope that the model trends eastward will continue, hopefully putting Irene down in history as a massive false alarm, but right now the models are ceasing the large shifts, and New England is right in the bullseye right now.

The reason the track has had to shift east is explained in the video. The upper pattern over eastern Canada has seen more low pressure than anticipated by forecasters and the models, including myself, sending a series of shortwaves across New England to attack the Bermuda High, weakening it enough to allow Irene to move more northeasterly. However, way back when Irene was over the northern lesser Antilles, I was talking about a track into South Carolina, so the shift to just off of Cape Hatteras from a 7-day forecast back on Sunday isn't really that bad. However, it could make all the difference in the world. As I have said, small shifts in the track lead to big jumps up or down the coast.

Overall, we have a very dangerous storm currently slamming the Bahamas with her full fury, and the outer banks of North Carolina may not escape her wrath either. She will pass near the outer banks on Saturday, and then continue on to New England, which may also have to deal with a hurricane, a weakening one, but strong enough to be a potential disaster for that region, and folks should be making preparations. We will hope and pray for a track east of everybody, which would be a miracle indeed, but for now, some of the largest populations centers in the United States are in the path of this major hurricane.

We shall see what happens!

Official NHC Forecast for Hurricane Irene:



Official NHC Public Advisory for Hurricane Irene:

000
WTNT34 KNHC 241442
TCPAT4

BULLETIN
HURRICANE IRENE ADVISORY NUMBER 17
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 AM EDT WED AUG 24 2011

...IRENE TURNS NORTHWESTWARD...EYE MOVING OVER CROOKED AND ACKLINS
ISLANDS...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...22.4N 73.9W
ABOUT 100 MI...160 KM SE OF LONG ISLAND BAHAMAS
ABOUT 285 MI...460 KM SE OF NASSAU
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...956 MB...28.23 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

NONE

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* THE SOUTHEASTERN...CENTRAL...AND NORTHWESTERN BAHAMAS

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE TURKS AND CAICOS ISLANDS

INTERESTS IN EASTERN NORTH CAROLINA AND THE MID-ATLANTIC STATES
SHOULD MONITOR THE PROGRESS OF IRENE.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF HURRICANE IRENE WAS
LOCATED NEAR LATITUDE 22.4 NORTH...LONGITUDE 73.9 WEST. IRENE IS
MOVING TOWARD THE NORTHWEST NEAR 12 MPH...19 KM/H...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE THROUGH TONIGHT. A TURN
TOWARD THE NORTH-NORTHWEST AND THEN NORTH ARE EXPECTED THURSDAY
AND THURSDAY NIGHT. ON THE FORECAST TRACK...THE CORE OF IRENE
WILL MOVE ACROSS THE SOUTHEASTERN AND CENTRAL BAHAMAS THROUGH
TONIGHT AND OVER THE NORTHWESTERN BAHAMAS ON THURSDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 115 MPH...185 KM/H...WITH HIGHER
GUSTS. IRENE IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME ADDITIONAL STRENGTHENING IS FORECAST
DURING THE DAY OR SO AND IRENE COULD BECOME A CATEGORY FOUR
HURRICANE BY THURSDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 50 MILES...85 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205
MILES...335 KM.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY RECONNAISSANCE
AIRCRAFT WAS 956 MB...28.23 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...HURRICANE CONDITIONS ARE OCCURRING OVER PORTIONS OF THE
SOUTHEASTERN BAHAMAS. TROPICAL STORM CONDITIONS ARE EXPECTED TO
BEGIN OVER THE CENTRAL BAHAMAS WITHIN THE NEXT FEW HOURS...WITH
HURRICANE CONDITIONS EXPECTED BY TONIGHT. TROPICAL STORM
CONDITIONS ARE EXPECTED IN THE NORTHWESTERN BAHAMAS BY LATE
TONIGHT...WITH HURRICANE CONDITIONS EXPECTED ON THURSDAY.

STORM SURGE...IN AREAS OF ONSHORE WINDS NEAR THE CENTER OF
IRENE...AN EXTREMELY DANGEROUS STORM SURGE WILL RAISE WATER LEVELS
BY AS MUCH AS 7 TO 11 FEET ABOVE NORMAL TIDE LEVELS OVER THE
BAHAMAS. A STORM SURGE OF 5 TO 8 FEET ABOVE NORMAL TIDE LEVELS IS
ALSO POSSIBLE IN AREAS OF ONSHORE WINDS OVER THE TURKS AND CAICOS
ISLANDS. NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE
AND DANGEROUS WAVES.

RAINFALL...IRENE IS EXPECTED TO PRODUCE ADDITIONAL RAINFALL
ACCUMULATIONS OF 1 TO 3 INCHES ACROSS HISPANIOLA WITH ISOLATED
MAXIMUM STORM TOTAL AMOUNTS OF 15 INCHES POSSIBLE. THESE RAINS
COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS
OF STEEP TERRAIN. RAINFALL ACCUMULATIONS OF 6 TO 12 INCHES ARE
EXPECTED IN THE BAHAMAS...AND THE TURKS AND CAICOS ISLANDS.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM EDT.
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BROWN



Hurricane Storm Irene Visible/IR2 Floater:



Hurricane Irene Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 4:02 PM GMT on August 24, 2011

Permalink

Irene to nail the Bahamas with her full fury - Eastern seaboard is likely next

By: Levi32, 4:20 PM GMT on August 23, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Hurricane Irene has not strengthened since yesterday, and remains a low-end Category 2 hurricane. As I mentioned yesterday morning, Irene will likely struggle to significantly intensify until she is well clear of Hispaniola. Inflow around her southeast side is coming into the eyewall right off the mountains of the Dominican Republic, which is drying out the air as it enters the storm. An eye is trying to show itself vaguely in visible imagery, but the dry air intrusions into the core off of Hispaniola are clearly inhibiting it right now. As a result, Irene is lopsided off to the east. This is aided by some dry air that remains west of the storm as well. Irene will eventually become more symmetric as she strengthens to peak intensity over the northwestern Bahamas, but will likely never attain perfect symmetry, as storms moving northward towards the eastern seaboard often don't. The Bahamas may get Irene's full fury at her peak intensity, which I still think could be as high as a low-end Category 4 of 135-140mph. Hopefully folks there are either leaving or hunkering down in a place that they know is safe in a storm like this. Structures down there are generally built very well.

Some good news for the U.S. is that Irene is likely to weaken some before her potential landfall in the Carolinas. I cannot find a storm that was strengthening or even maintaining intensity at landfall in North Carolina if it was already a major near the Bahamas. It doesn't really happen, with the reason being that a storm coming up close to Florida starts pulling dry air off the continent for quite a while before it reaches the North Carolina coast, which weakens the storm. The nature of such a northward track also implies that an upper trough is usually nearby, enhancing the dry air and shearing the storm as well. If Irene makes it to a high Cat 3 or low Cat 4 in the Bahamas, I would expect a low-end Cat 3 or high Cat 2 at a potential North Carolina landfall.

The track philosophy remains similar to what it has been. The break between the Texas and Atlantic ridges should draw Irene up the eastern seaboard, likely now to be a North Carolina landfall. My track has shifted a little bit up the coast from upper South Carolina to North Carolina, just northeast of Wilmington. We have had this general idea set up for a while now, and most of the Meteorology has been done with the track of this storm. We are now in that time where fine details rule the world, and those painfully small details will be what determines where this storm goes now. This is where our computer models start becoming more heavily relied on, even by me. At some point before landfall, the models become very bunched up and rarely mess up the track very badly. We are still 4 days from a potential landfall, and thus there is still quite a bit of room for error, so don't think that the track is locked down just yet. Florida looks like they will avoid a direct hit here, but the track could take Irene within 150 miles of the coast, which could still spread tropical storm conditions over the eastern parts of Florida. Folks from South Carolina northward should be preparing for a strong hurricane, possibly a major, to be affecting their areas by early this weekend.

If Irene hits North Carolina as forecasted, then she would likely move up into the New England area, which would take her impacts into the main population centers of the northeast. Folks have to realize that even a weakening Cat 1 is a big deal in this region, and we could be in for significant damages up towards the big cities. Folks up that way should be watching this carefully as well.

Some models are trying now to take Irene out to sea east of the U.S. altogether. This is obviously something to hope and pray for, and can't be ruled out, but I still think it's a bit too much to ask for a storm riding up the length of the Bahamas in this pattern to miss the U.S. completely. Again, 4 days allows lots of things to change still, and the track is not set in stone.

I can't stress enough that people should be reviewing their evacuation plans along the east coast and have a plan ready to be set in motion soon, as this could be a major event that could take away lives and property.

We shall see what happens!

Official NHC Forecast for Hurricane Irene:



Official NHC Public Advisory for Hurricane Irene:

000
WTNT34 KNHC 231450
TCPAT4

BULLETIN
HURRICANE IRENE ADVISORY NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 AM EDT TUE AUG 23 2011

...IRENE APPROACHING THE TURKS AND CAICOS ISLANDS...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...20.5N 71.0W
ABOUT 70 MI...110 KM S OF GRAND TURK ISLAND
ABOUT 50 MI...85 KM NNW OF PUERTO PLATA DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...100 MPH...160 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...980 MB...28.94 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE GOVERNMENT OF THE BAHAMAS HAS CHANGED THE HURRICANE WATCH FOR
THE NORTHWESTERN BAHAMAS TO A HURRICANE WARNING.

THE GOVERNMENT OF THE DOMINICAN REPUBLIC HAS CHANGED THE HURRICANE
WARNING ALONG THE NORTH COAST OF THE DOMINICAN REPUBLIC TO A
TROPICAL STORM WARNING.

THE TROPICAL STORM WARNING FOR HAITI SOUTH OF LE MOLE ST.
NICHOLAS HAS BEEN DISCONTINUED.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* TURKS AND CAICOS ISLANDS
* THE SOUTHEASTERN...CENTRAL...AND NORTHWESTERN BAHAMAS

A HURRICANE WATCH IS IN EFFECT FOR...
* NORTH COAST OF HAITI FROM LE MOLE ST. NICHOLAS EASTWARD TO THE
DOMINICAN REPUBLIC BORDER

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* NORTH COAST OF THE DOMINICAN REPUBLIC FROM CABO ENGANO WESTWARD TO
THE HAITI BORDER
* NORTH COAST OF HAITI FROM LE MOLE ST. NICHOLAS EASTWARD TO THE
DOMINICAN REPUBLIC BORDER

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF HURRICANE IRENE WAS
LOCATED BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT NEAR
LATITUDE 20.5 NORTH...LONGITUDE 71.0 WEST. IRENE IS MOVING TOWARD
THE WEST-NORTHWEST NEAR 12 MPH...19 KM/H. THIS GENERAL MOTION IS
EXPECTED TO CONTINUE THROUGH TONIGHT...FOLLOWED BY A TURN TOWARD
THE NORTHWEST ON WEDNESDAY. ON THE FORECAST TRACK...THE CORE OF
IRENE WILL MOVE NEAR OR OVER THE TURKS AND CAICOS ISLANDS AND THE
SOUTHEASTERN BAHAMAS TONIGHT...BE NEAR THE CENTRAL BAHAMAS EARLY
WEDNESDAY...AND NEAR OR OVER THE NORTHWESTERN BAHAMAS ON THURSDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 100 MPH...160 KM/H...WITH HIGHER
GUSTS. IRENE IS A CATEGORY TWO HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. STRENGTHENING IS FORECAST DURING THE NEXT
48 HOURS...AND IRENE COULD BECOME A MAJOR HURRICANE BY WEDNESDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 50 MILES...85 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205
MILES...335 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 980 MB...28.94 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS WILL CONTINUE OVER NORTHERN
PORTIONS OF THE DOMINICAN REPUBLIC THROUGH THIS AFTERNOON. TROPICAL
STORM CONDITIONS ARE SPREADING OVER THE SOUTHEASTERN BAHAMAS AND
THE TURKS AND CAICOS ISLANDS WITH HURRICANE CONDITIONS EXPECTED
BY THIS AFTERNOON AND EVENING. TROPICAL STORM CONDITIONS ARE
FORECAST TO REACH THE CENTRAL BAHAMAS LATE TONIGHT WITH HURRICANE
CONDITIONS EXPECTED BY WEDNESDAY. TROPICAL STORM CONDITIONS ARE
EXPECTED IN THE NORTHWESTERN BAHAMAS BY LATE WEDNESDAY...WITH
HURRICANE CONDITIONS EXPECTED BY THURSDAY.

STORM SURGE...AN EXTREMELY DANGEROUS STORM SURGE WILL RAISE WATER
LEVELS BY AS MUCH AS 9 TO 13 FEET ABOVE NORMAL TIDE LEVELS OVER THE
BAHAMAS AND THE TURKS AND CAICOS ISLANDS...NEAR AND TO THE NORTH OF
THE CENTER OF IRENE. A STORM SURGE WILL ALSO RAISE WATER LEVELS BY
AS MUCH AS 2 TO 4 FEET ABOVE NORMAL TIDE LEVELS ALONG THE NORTH
COAST OF HAITI AND THE ENTIRE COAST OF THE DOMINICAN REPUBLIC. NEAR
THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS
WAVES.

RAINFALL...IRENE IS EXPECTED TO PRODUCE ADDITIONAL RAINFALL
ACCUMULATIONS OF 1 TO 3 INCHES ACROSS PUERTO RICO. RAINFALL
AMOUNTS OF 4 TO 8 INCHES ARE EXPECTED OVER NORTHERN HISPANIOLA...
WITH ISOLATED MAXIMUM AMOUNTS OF UP TO 15 INCHES POSSIBLE OVER
HIGHER TERRAIN. THESE RAINS COULD CAUSE LIFE-THREATENING FLASH
FLOODS AND MUDSLIDES IN AREAS OF STEEP TERRAIN. RAINFALL
ACCUMULATIONS OF 5 TO 10 INCHES ARE EXPECTED IN THE SOUTHEASTERN
AND CENTRAL BAHAMAS...AND THE TURKS AND CAICOS ISLANDS.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM EDT.
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BROWN/BLAKE



Hurricane Storm Irene Visible/IR2 Floater:



Hurricane Irene Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 4:21 PM GMT on August 23, 2011

Permalink

Irene to threaten the Bahamas and Southeast U.S. as a major hurricane

By: Levi32, 4:10 PM GMT on August 22, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Irene is now a Cat 1 hurricane, the first of the 2011 Atlantic Hurricane Season. She roared through Puerto Rico last night, knocking the main radar tower offline and a couple of weather stations as well. Irene has an eye now with an eyewall that is still open to the south, and core convection could be stronger, but she is strengthening steadily again. As mentioned yesterday, Irene's track has had to shift northward, and will now take her very close to the northern Dominican Republic, possibly offshore and avoiding a direct pass over the tall mountains there. This is good news for Hispaniola, but bad news for the Bahamas and the United States, as it will allow significant strengthening to occur with minimal disruption to Irene's core after passing Hispaniola. Some disruption will still occur as air sinks down the mountain slopes into the storm's eye, which will serve to dry out the inflow, but the interaction should not result in significant weakening. Irene is likely to be a major hurricane once she gets through the Bahamas over the very warm water there, under a favorable upper-level environment, and folks need to take this storm seriously. The NHC 11am EDT forecast now has Irene up to Cat 3 as well.

The track forecast philosophy for Irene remains mostly the same. A trough is currently nearing maximum amplification over the northeastern U.S., and will be lifting out quickly tomorrow and Wednesday. This will allow Irene to start moving northwest through the Bahamas, but as the trough leaves, the ridge building in from the east will force her to remain on a northwest track for a while, taking a close pass to Florida. The weakness between the Texas ridge and the Bermuda ridge will remain in place over the southeast U.S. coast, allowing Irene to move directly into it towards a landfall somewhere between Florida and Cape Hatteras. My track still takes Irene into South Carolina, but folks should be advised that only small nudges west or east in the forecast track can lead to great shifts up and down the SE US coastline and cause the landfall to occur in different states. Thus, everyone in the area should be ready and preparing for this storm. We are still 5 days away from a potential landfall, so there is room for things to change. That also gives the storm lots of time to strengthen, as we mentioned above. Although the forecast models generally keep the storm east of Florida right now, the fact that it will be a strong hurricane means that a pass close by could still give tropical storm or hurricane conditions to portions of the Florida coastline, and thus residents there should still be closely watching Irene as well. A select few of the models now suggest that Irene could slip east of North Carolina and out to sea, but I believe this to be an overdone solution at this time given the upper air pattern that we are currently dealing with. Regardless, such a solution is of course something to hope and root for.

The northeast U.S. may have to watch Irene as well, as the track may take her northeast after making landfall and bring strong winds and heavy rain to the populated cities of New England. This could be a classic east coast storm that moves up the entire seaboard, resulting in heavy damages.

Overall, Irene is a storm to take seriously, and it is a real likelyhood that she will be a major hurricane as she approaches the southeast United States. This is the real deal. Impacts could be felt in Florida as soon as 3 days from now, but we have about 5 days until a potential landfall if it occurs north of Florida, so folks have a lot of time to prepare, but they should begin right now. It's never too early to do so. Have your hurricane plans ready to go in case of an evacuation. The Bahamas are next to get a direct hit from Irene, and folks there are hopefully already ready for this. Rain bands will be affecting the southeastern Bahamas as soon as this evening.

We shall see what happens!

Official NHC Forecast for Hurricane Irene:



Official NHC Public Advisory for Hurricane Irene:

000
WTNT34 KNHC 221503
TCPAT4

BULLETIN
HURRICANE IRENE ADVISORY NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 AM AST MON AUG 22 2011

...IRENE FORECAST TO PASS JUST TO THE NORTH OF HISPANIOLA...

SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.2N 67.5W
ABOUT 105 MI...170 KM WNW OF SAN JUAN PUERTO RICO
ABOUT 70 MI...115 KM NE OF PUNTA CANA DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...988 MB...29.18 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A HURRICANE WARNING FOR THE
TURKS AND CAICOS ISLANDS AND THE SOUTHEASTERN BAHAMAS.

THE TROPICAL STORM WARNING FOR THE BRITISH AND U.S VIRGIN ISLANDS
HAS BEEN DISCONTINUED.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* NORTH COAST OF THE DOMINICAN REPUBLIC FROM THE HAITI BORDER
EASTWARD TO CABO ENGANO
* SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS

A HURRICANE WATCH IS IN EFFECT FOR...
* NORTH COAST OF HAITI FROM LE MOLE ST. NICHOLAS EASTWARD TO THE
DOMINICAN REPUBLIC BORDER
* CENTRAL BAHAMAS

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* PUERTO RICO...VIEQUES AND CULEBRA
* SOUTH COAST OF THE DOMINICAN REPUBLIC FROM SOUTH OF CABO ENGANO
WESTWARD TO THE HAITI BORDER
* ALL OF HAITI

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM AST...1500 UTC...THE CENTER OF HURRICANE IRENE WAS
LOCATED NEAR LATITUDE 19.2 NORTH...LONGITUDE 67.5 WEST. IRENE IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 13 MPH...20 KM/H...AND THIS
MOTION IS EXPECTED TO CONTINUE DURING THE NEXT 24 TO 48 HOURS. ON
THIS TRACK THE CORE OF IRENE SHOULD BE PASSING JUST TO THE NORTH OF
HISPANIOLA LATER TODAY AND EARLY TUESDAY AND REACH THE TURKS AND
CAICOS ISLANDS AND THE SOUTHEASTERN BAHAMAS LATE TUESDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 80 MPH...130
KM/H...WITH HIGHER GUSTS. IRENE IS A CATEGORY ONE HURRICANE ON THE
SAFFIR-SIMPSON HURRICANE SCALE. STRENGTHENING IS FORECAST DURING
THE NEXT FEW DAYS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185
MILES...295 KM TO THE NORTHEAST OF THE CENTER.

MINIMUM CENTRAL PRESSURE ESTIMATED FROM A RECONNAISSANCE PLANE WAS
988 MB...29.18 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS SHOULD GRADUALLY DECREASE IN PUERTO
RICO THIS MORNING. TROPICAL STORM CONDITIONS WILL REACH THE
NORTHERN PORTION OF DOMINICAN REPUBLIC BY THIS AFTERNOON. HURRICANE
CONDITIONS ARE POSSIBLE OVER THE NORTHERN PORTIONS OF THE DOMINICAN
REPUBLIC LATER TODAY. THE HIGHEST WINDS ARE LIKELY TO OCCUR OVER
AREAS OF ELEVATED TERRAIN. HURRICANE CONDITIONS ARE EXPECTED TO
REACH THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS
TUESDAY...AND ARE POSSIBLE IN THE CENTRAL BAHAMAS BY LATE TUESDAY.

RAINFALL...IRENE IS EXPECTED TO PRODUCE ADDITIONAL RAINFALL
ACCUMULATIONS OF 2 TO 4 INCHES ACROSS PUERTO RICO...THE VIRGIN
ISLANDS. RAINFALL AMOUNTS OF 3 TO 6 INCHES ARE EXPECTED OVER
NORTHERN HISPANIOLA...WITH ISOLATED AMOUNTS OF UP TO 10 INCHES
POSSIBLE OVER HIGHER TERRAIN. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS OF STEEP
TERRAIN. RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES ARE POSSIBLE THE
SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 2
TO 4 FEET ABOVE NORMAL TIDE LEVELS ALONG THE ENTIRE COAST OF THE
DOMINICAN REPUBLIC. STORM SURGE WILL ALSO RAISE WATER LEVELS BY AS
MUCH AS 4 TO 6 FEET ABOVE NORMAL TIDE LEVELS OVER THE SOUTHEASTERN
BAHAMAS AND TURKS AND CAICOS. NEAR THE COAST...THE SURGE WILL BE
ACCOMPANIED BY LARGE AND DANGEROUS WAVES. ELEVATED WATERS LEVELS
WILL GRADUALLY SUBSIDE TODAY IN PUERTO RICO AND THE VIRGIN ISLANDS.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM AST.
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER AVILA



Hurricane Storm Irene Visible/IR2 Floater:



Hurricane Irene Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

Irene to hit Puerto Rico directly, coming in farther north, may hit Carolinas instead

By: Levi32, 4:54 PM GMT on August 21, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Tropical Storm Irene developed a bit quicker than expected yesterday. Organization has been slow overnight due to the large nature of the system. The core convection is not that strong this morning, as some mid-level dry air is infiltrating the system at the moment, shown by the sounding out of San Juan at 12z. Irene's mid-level center is apparent on satellite imagery, with recon insisting that the surface center is farther south. While the pressure center is there, southerly winds are being found directly north of it, indicating that the surface center is about to reform beneath the mid-level one and become vertically stacked, at which point it will be better able to strengthen.

The storm is now north of where the models and NHC had it, and may move more directly over Puerto Rico, fulfilling their tropical storm warning to the fullest. This is bad news for everyone, as Irene may now avoid the bulk of Hispaniola and only scrape the northern portion. If Irene becomes stacked and mixes out the dry air, and if Puerto Rico doesn't significantly negatively impact the core, then the Dominican Republic could be dealing with a minimal hurricane by the time it nears the coast.

Down the road this is bad news for the United States, as less interaction means more time over water, and Irene could have a decent amount of time to strengthen before threatening the United States. What makes it worse is that the track may now take her east of Florida, and up into the Carolinas instead, giving her even more time over the warm waters of the Gulf Stream. The eastern Gulf of Mexico is taken out of the equation now, and this is a threat to east Florida up through Georgia and the Carolinas. The steering pattern is gone over again in the video, describing how the ridge building back in as the trough exits should result in a straight north or NNW track into the coast, with no giant trough trying to recurve the storm rapidly. This won't be a fast-mover coming in, and we could potentially be talking about a major hurricane threatening the southeast U.S. coastline in 4-5 days. This is not meant to frighten or alarm anybody, but folks should make sure that their hurricane plans are ready to execute in case their area is targeted. This is a real storm that has the look of a peak of the season hurricane that could get pretty strong if conditions are as favorable as they look right now in the Bahamas area. Folks from Puerto Rico and Hispaniola should already be prepared for this, and the Bahamas are next to feel the effects.

We shall see what happens!

Official NHC Forecast for Tropical Storm Irene:



Official NHC Public Advisory for Tropical Storm Irene:

000
WTNT34 KNHC 211456
TCPAT4

BULLETIN
TROPICAL STORM IRENE ADVISORY NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011
1100 AM AST SUN AUG 21 2011

...IRENE EXPECTED TO STRENGTHEN AND PASS NEAR PUERTO RICO TONIGHT...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.0N 63.2W
ABOUT 235 MI...375 KM ESE OF PONCE PUERTO RICO
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 20 MPH...32 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

THE TROPICAL STORM WARNING FOR PUERTO RICO...VIEQUES...AND CULEBRA
IS CHANGED TO A HURRICANE WARNING.

A HURRICANE WATCH HAS BEEN ISSUED FOR THE U.S. VIRGIN ISLANDS.

THE GOVERNMENT OF THE DOMINICAN REPUBLIC HAS CHANGED THE TROPICAL
STORM WARNING TO A HURRICANE WARNING FOR THE NORTH COAST OF THE
DOMINICAN REPUBLIC FROM CABO ENGANO TO CABO FRANCES VIEJO.

THE TROPICAL STORM WATCH FOR HAITI IS CHANGED TO A TROPICAL STORM
WARNING.

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A TROPICAL STORM WATCH FOR
THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* PUERTO RICO...VIEQUES...AND CULEBRA
* THE DOMINICAN REPUBLIC FROM THE SOUTHERN BORDER WITH HAITI TO CABO
FRANCES VIEJO ON THE NORTH COAST

A HURRICANE WATCH IS IN EFFECT FOR...
* U.S. VIRGIN ISLANDS

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* U.S. VIRGIN ISLANDS
* SABA...ST. EUSTATIUS...ST. MAARTEN...ST. MARTIN...AND ST.
BARTHELEMY
* ANTIGUA...BARBUDA...ST. KITTS...NEVIS...ANGUILLA...MONTSERRAT
* BRITISH VIRGIN ISLANDS
* NORTHERN COAST OF THE DOMINICAN REPUBLIC FROM THE HAITI BORDER
EASTWARD TO CABO FRANCES VIEJO
* HAITI

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL
WEATHER SERVICE FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO
YOUR AREA OUTSIDE THE UNITED STATES...PLEASE MONITOR PRODUCTS
ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL STORM IRENE WAS
LOCATED NEAR LATITUDE 17.0 NORTH...LONGITUDE 63.2 WEST. IRENE IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 20 MPH...32 KM/H...AND THIS
MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS WITH A
GRADUAL DECREASE IN FORWARD SPEED. ON THE FORECAST TRACK...IRENE
WILL PASS NEAR PUERTO RICO TONIGHT OR EARLY MONDAY AND APPROACH THE
DOMINICAN REPUBLIC ON MONDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/H...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT DAY OR
SO...AND IRENE COULD BECOME A HURRICANE ON MONDAY.

TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 150 MILES...240
KM...MAINLY TO THE NORTH OF THE CENTER.

AN AIR FORCE HURRICANE HUNTER AIRCRAFT REPORTED A MINIMUM CENTRAL
PRESSURE OF 1007 MB...29.74 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED IN THE LEEWARD ISLANDS
TODAY. TROPICAL STORM CONDITIONS ARE EXPECTED TO BEGIN THIS
AFTERNOON IN THE VIRGIN ISLANDS AND PUERTO RICO...AND IN THE
DOMINICAN REPUBLIC EARLY MONDAY. HURRICANE CONDITIONS ARE
EXPECTED OVER PUERTO RICO...VIEQUES...AND CULEBRA TONIGHT...AND OVER
THE DOMINICAN REPUBLIC ON MONDAY.

RAINFALL...IRENE IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 4 TO 7 INCHES IN THE LEEWARD ISLANDS...PUERTO RICO AND THE
VIRGIN ISLANDS...WITH ISOLATED MAXIMUM AMOUNTS OF UP TO 10 INCHES.
TOTAL RAINFALL ACCUMULATIONS OF 6 TO 10 INCHES ARE POSSIBLE ACROSS
THE DOMINICAN REPUBLIC AND HAITI...WITH ISOLATED MAXIMUM AMOUNTS OF
20 INCHES POSSIBLE. THESE RAINS COULD CAUSE LIFE-THREATENING FLASH
FLOODS AND MUD SLIDES IN AREAS OF STEEP TERRAIN.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 3
TO 5 FEET ABOVE NORMAL TIDE LEVELS ALONG THE COAST OF THE DOMINICAN
REPUBLIC IN THE HURRICANE WARNING AREA. A STORM SURGE OF 1 TO 3
FEET ABOVE NORMAL TIDE LEVELS IS EXPECTED ALONG THE COAST OF PUERTO
RICO...AS WELL AS IN THE TROPICAL STORM WARNING AREA. NEAR THE
COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS WAVES.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM AST.
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER PASCH


San Juan, Puerto Rico Radar Loop:



Tropical Storm Irene Visible/IR2 Floater:



Tropical Storm Irene Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 5:27 PM GMT on August 21, 2011

Permalink

Harvey nearing landfall as a moderate tropical storm; 97L likely to be a big problem

By: Levi32, 4:09 PM GMT on August 20, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Tropical Storm Harvey still has a pressure of 999mb, with no change in strength since yesterday afternoon. Proximity to land and lack of vertical stacking of the center has kept the storm under hurricane intensity, as outlined yesterday, and the landfall forecast of up to 60mph looks good, as Harvey should not significantly change in strength before moving into Belize later today. This will be mainly a rainfall event for them, though folks should still stay safe even though it is only a tropical storm, as 60mph sustained winds are still dangerous. Harvey will dissipate over central America after moving inland.

Invest 97L is going to be a big-ticket item next week. Thunderstorm activity is increasing in coverage over a broad area of low pressure east of the lesser Antilles islands this morning. The system is not quite as broad and elongated as it was yesterday, but it is still very large, and if there is any kind of a circulation center, it's way down to the south near 12N where some weak westerlies are being seen on visible satellite imagery. The surface center that finally winds up could develop anywhere between this area and 15N, and this will be very important for the future track. A center forming farther south could result in 97L tracking south of the major Caribbean islands, eventually landing in the eastern Gulf of Mexico with lots of time over water. A center forming farther north could take the track directly over the Greater Antilles or just north of them, resulting in a weaker intensity but directly affecting more people.

For now, my track will be based off of the main center eventually forming where low-level vorticity and convergence are greatest, which is currently near 14N, 56W, moving WNW. The main steering feature over the next 4 days will be a trough currently diving out of northern Canada, and will be digging in over New England in 48-72 hours. On Tuesday, this trough will reach maximum amplification near 75W before butting up against the big west Atlantic ridge, at which point it will lift out in a hurry. This positions the weakness in the ridge along 75W, meaning that 97L should gain a bit of latitude and move more NW than WNW for a short time near Hispaniola, possibly enough to take the system across the island and then just north of it. As the upper trough leaves, the ridge builds in strongly from the east, which would push 97L back to a WNW track into the Bahamas and southeast Florida, as the weakness in the ridge retrogrades westward into the eastern Gulf of Mexico. The storm would then curve north into this weakness somewhere along the length of Florida or just a hair on either side of the peninsula.

This track would knock down the system in strength due to interaction with Hispaniola, but it would have some time over water between there and Florida to strengthen into a potent system. The global models constantly strengthen this storm regardless of how much land it runs into. Even the GFS and ECMWF, which take it directly over Hispaniola AND the length of Cuba, still strengthen it as time goes on. These two models actually show the storm being stronger inland over Florida and Georgia than it is when it makes landfall. This says a lot about how favorable conditions are in that area of the world, and this is reason to be concerned, even if Hispaniola and/or Cuba take the brunt of the storm first for the United States.

Overall, there is still a lot of uncertainty on the exact track due to the fact that we don't have a defined center for 97L yet, and thus the intensity forecast has uncertainty as well due to potential land interaction, or lack thereof. What IS certain is that this storm is going to directly impact the Greater Antilles, and then the southeast United States, with Florida being at greatest risk. We could easily be dealing with a hurricane eventually, again depending on land interaction. The lesser Antilles will only be impacted by gusty winds and showers today. Puerto Rico could still get a close pass from this system, though it should pass by to the south, and thus they should be prepared for possible tropical storm conditions, as should Hispaniola. Jamaica, Cuba, and the Bahamas should all be preparing for a tropical cyclone as well. If 97L were to slip south of Hispaniola instead of over it, Cuba would likely have to deal with a hurricane. Florida, despite having Caribbean island guards, may get a potent system from 97L, and should also be getting ready for a tropical cyclone in 4-5 days, possibly a hurricane.

We shall see what happens!


Official NHC Forecast for Tropical Storm Harvey:



Official NHC Public Advisory for Tropical Storm Harvey:

000
WTNT33 KNHC 201453
TCPAT3

BULLETIN
TROPICAL STORM HARVEY ADVISORY NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082011
1000 AM CDT SAT AUG 20 2011

...HARVEY MOVING WESTWARD TOWARD BELIZE WITH LITTLE CHANGE IN
STRENGTH...


SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.8N 87.6W
ABOUT 65 MI...100 KM SE OF BELIZE CITY
ABOUT 70 MI...110 KM ENE OF MONKEY RIVER TOWN BELIZE
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF HONDURAS HAS DISCONTINUED THE TROPICAL STORM
WARNING FOR THE BAY ISLANDS AND FOR THE NORTHERN COAST OF HONDURAS
EAST OF PUNTA SAL.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE COAST OF HONDURAS FROM PUNTA SAL WESTWARD
* THE COAST OF GUATEMALA
* THE COAST OF BELIZE

HURRICANE CONDITIONS ARE POSSIBLE ALONG A PORTION OF THE COAST OF
BELIZE LATER TODAY.

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN
THE NEXT 24 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1000 AM CDT...1500 UTC...THE CENTER OF TROPICAL STORM HARVEY WAS
LOCATED NEAR LATITUDE 16.8 NORTH...LONGITUDE 87.6 WEST. HARVEY IS
MOVING TOWARD THE WEST NEAR 12 MPH...19 KM/H...AND THIS MOTION IS
EXPECTED TO CONTINUE FOR THE NEXT DAY OR TWO. ON THE FORECAST
TRACK...THE CENTER OF HARVEY WILL MOVE INLAND OVER BELIZE THIS
AFTERNOON...THEN MOVE INTO NORTHERN GUATEMALA TONIGHT.

REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/H...WITH
HIGHER GUSTS. SOME STRENGTHENING IS POSSIBLE TODAY...AND HARVEY
COULD BECOME A HURRICANE BEFORE LANDFALL IN BELIZE. STEADY
WEAKENING IS FORECAST AFTER LANDFALL.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 45 MILES...75 KM
MAINLY TO THE NORTH OF THE CENTER.

THE MINIMUM CENTRAL PRESSURE ESTIMATED FROM THE HURRICANE HUNTER
AIRCRAFT DATA IS 998 MB...29.47 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL-STORM-FORCE WINDS ARE EXPECTED ALONG THE NORTHERN
COAST OF HONDURAS IN THE WARNING AREA THROUGH THIS AFTERNOON.
TROPICAL-STORM-FORCE WINDS ARE ALSO EXPECTED ALONG THE COASTS OF
GUATEMALA AND BELIZE BY THIS AFTERNOON. HURRICANE-FORCE WINDS ARE
POSSIBLE ALONG A PORTION OF THE COAST OF BELIZE THIS AFTERNOON.

RAINFALL...HARVEY IS EXPECTED TO PRODUCE TOTAL RAINFALL
ACCUMULATIONS OF 3 TO 6 INCHES ACROSS HONDURAS...GUATEMALA...
BELIZE...AND THE YUCATAN PENINSULA OF MEXICO...WITH POSSIBLE
ISOLATED MAXIMUM AMOUNTS OF 10 INCHES. THESE RAINS COULD PRODUCE
LIFE-THREATENING FLASH FLOODS AND MUDSLIDES...ESPECIALLY OVER
HIGHER TERRAIN.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 2
TO 4 FEET ABOVE NORMAL TIDE LEVELS ALONG THE COAST NEAR AND TO THE
NORTH OF WHERE HARVEY MAKES LANDFALL. NEAR THE COAST...THE SURGE
WILL BE ACCOMPANIED BY LARGE AND DAMAGING WAVES.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...100 PM CDT.
NEXT COMPLETE ADVISORY...400 PM CDT.

$$
FORECASTER BEVEN



Tropical Storm Harvey Visible/IR2 Floater:



Invest 97L Visible/IR2 Floater:



Invest 97L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

TD 8 to strengthen more before hitting Belize; 97L to affect the U.S. eventually

By: Levi32, 3:30 PM GMT on August 19, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Tropical Depression #8 is just offshore of Honduras, moving westward along the coast. The recon that went in shortly ago found the center to be northeast of where the NHC had it, and TD 8 could stay several dozen miles offshore of Honduras for the next couple of days, bringing it instead into Belize. Because of this, some additional strengthening may occur, and we could see a moderate tropical storm of 50-60mph strength before landfall in Belize. The environment around TD 8 is the most favorable that it has had so far. Two upper lows to the west are backing away, allowing air to expand over the storm, which helps to lower surface pressures. The western Caribbean has also moistened up a lot over the last couple of days, aided by the fact that the MJO is back over our basin. This should still be mainly a rain even for Honduras and Belize, but Belize should be aware that winds with this may be a bit stronger than they expected as it comes ashore in about 36 hours.

Invest 97L is the next big story that will be on people's minds in a big way next week. This wave passed a buoy last night that showed pressures down to 1007mb, and it has a broad but well-defined circulation. There is dry air still wrapped up with it, but thunderstorms are continuing to fire in the NW quadrant of the circulation, and as this feature comes west, it is moving over warmer water today which will help it mix out the dry air over time. Due to its size and the dry air, development should be slow and gradual, probably not amounting to much in the leeward Antilles, but it may look more like a storm by the time it reaches the Hispaniola/PR area.

97L should cross the leewards near Martinique or Dominica, and I believe it will pass south of Puerto Rico, as opposed to directly over it. That doesn't mean that PR shouldn't expect tropical storm conditions, as if this develops south of them, its size means that conditions will still deteriorate a lot there. There are two main possibilities I see for the long-term track. The first is that 97L moves near Hispaniola and then gets drawn north of the island, then forced to move through the Bahamas towards Florida, perhaps riding up the east coast. The other possibility is that it slips just south of Hispaniola and Cuba, eventually moving into the eastern Gulf of Mexico. The entire U.S. coast from the Mississippi River delta to the Carolinas could still see direct effects from this system, and I'm not yet sure which of these path possibilities it will take. We need to see how fast it tries to develop near the eastern Caribbean, as a slow developer will tend to stay south, while a quick ramp-up could mean it gets drawn north of the Caribbean.

The video explains how the pattern favors a U.S. landfall almost no matter what, probably with Caribbean island impacts before that. The pattern also shows us that a landfall in the western gulf is unlikely, despite the need for rain there, and this storm looks like a storm for the Mississippi River delta eastward. If it's a gulf storm, it should be the central-eastern gulf.

We shall see what happens!

Official NHC Forecast for TD #8:



Official NHC Public Advisory for TD #8:

000
WTNT33 KNHC 191450
TCPAT3

BULLETIN
TROPICAL DEPRESSION EIGHT ADVISORY NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082011
1100 AM EDT FRI AUG 19 2011

...HURRICANE HUNTER AIRCRAFT FINDS DEPRESSION JUST BELOW
TROPICAL-STORM STRENGTH...TROPICAL STORM WARNING ISSUED...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.1N 83.7W
ABOUT 195 MI...310 KM E OF ISLA ROATAN HONDURAS
ABOUT 315 MI...505 KM ESE OF BELIZE CITY
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF HONDURAS HAS ISSUED A TROPICAL STORM WARNING FOR
THE BAY ISLANDS OF HONDURAS.

THE GOVERNMENT OF BELIZE HAS ISSUED A TROPICAL STORM WATCH FOR THE
COAST OF BELIZE FROM DANGRIGA TOWN SOUTHWARD TO THE BELIZE/GUATEMALA
BORDER. A TROPICAL STORM WARNING WILL LIKELY BE ISSUED FOR THIS
AREA LATER TODAY.

THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WATCH FOR THE
SOUTHEASTERN COAST OF THE YUCATAN PENINSULA FROM PUNTA GRUESA
SOUTHWARD TO CHETUMAL.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE BAY ISLANDS OF HONDURAS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* THE COAST OF HONDURAS
* THE COAST OF GUATEMALA
* THE COAST OF BELIZE FROM DANGRIGA TOWN SOUTHWARD TO THE BELIZE/
GUATEMALA BORDER
* THE SOUTHEASTERN COAST OF THE YUCATAN PENINSULA FROM PUNTA GRUESA
SOUTHWARD TO CHETUMAL

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE AT ANY TIME WITHIN THE
NEXT 48 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF TROPICAL DEPRESSION EIGHT
WAS LOCATED NEAR LATITUDE 16.1 NORTH...LONGITUDE 83.7 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST NEAR 10 MPH...17 KM/H. A
GENERAL WESTWARD TO WEST-NORTHWESTWARD MOTION IS EXPECTED DURING
THE NEXT COUPLE OF DAYS. ON THE FORECAST TRACK...THE CENTER OF THE
DEPRESSION WILL PASS NEAR THE BAY ISLANDS OF HONDURAS TONIGHT AND
MOVE ACROSS THE COAST OF BELIZE SATURDAY OR SATURDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS. SATELLITE IMAGERY AND REPORTS FROM AN AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT INDICATE THAT THE DEPRESSION IS GETTING
BETTER ORGANIZED...AND IT IS EXPECTED TO BECOME A TROPICAL STORM
LATER TODAY.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY THE HURRICANE HUNTER
AIRCRAFT IS 1005 MB...29.68 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL-STORM-FORCE WINDS ARE EXPECTED OVER THE BAY ISLANDS
OF HONDURAS TONIGHT...AND OVER THE COAST OF BELIZE SATURDAY OR
SATURDAY NIGHT. TROPICAL-STORM-FORCE WINDS ARE POSSIBLE ALONG THE
NORTHERN COAST OF HONDURAS TODAY AND TONIGHT...ALONG THE NORTHERN
COAST OF GUATEMALA ON SATURDAY...AND ALONG THE SOUTHEASTERN COAST
OF THE YUCATAN PENINSULA OF MEXICO SATURDAY OR SATURDAY NIGHT.

RAINFALL...THE DEPRESSION IS EXPECTED TO PRODUCE TOTAL RAINFALL
ACCUMULATIONS OF 3 TO 5 INCHES ACROSS HONDURAS...GUATEMALA...AND
BELIZE...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 8 INCHES. THESE
RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES...
ESPECIALLY OVER HIGHER TERRAIN.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM EDT.
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BEVEN


Tropical Depression #8 Visible/IR2 Floater:



Tropical Depression #8 Track Forecast Models:



Invest 97L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 3:50 PM GMT on August 19, 2011

Permalink

93L poised to develop, could strengthen if it remains over water; Watching 97L

By: Levi32, 5:03 PM GMT on August 18, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Invest 93L is our first concern this morning, as it is threatening land right now. After showing no signs of a surface circulation yesterday, despite a vigorous mid-level circulation, 93L is showing signs of working that circulation down to the surface this morning, and looks poised to become a tropical depression or storm. A recon plane will soon be investigating the system to see whether this is classifiable yet. I do believe this will get classified sometime today, and may get named Harvey fairly quickly. The overall environment around 93L is much more conducive for strengthening than it was a couple of days ago, with much of the dry air around the system getting mixed out. The system is also moving slower than it was, illustrating how the trade winds are piling up in the Caribbean as they put on the breaks, forcing air to rise, which supports thunderstorm activity. 93L is a very small system, and thus strengthening could occur rapidly as long as it is over water.

The track of 93L will be generally westward, very close to the northern coast of Honduras. Depending on where the recon plane finds the surface center, this track could take it just inland over Honduras, or just north of the coastline over the water, which would then mean a landfall in Belize, with double the time over water that it would have otherwise. 50 miles could make a huge difference here with this storm. Due to 93L's small size, if the center moves onto Honduras even by a few miles, the system will likely dissipate quickly, but if it is even a few miles offshore, it could strengthen a bit. It is possible that we could see a moderate-strong tropical storm if it makes landfall in Belize instead of Honduras. Either way, rainfall will probably be the primary issue with this storm, but we could see some hefty winds if it slips just north of Honduras and remains over the water, so folks in the area should keep a close eye on this. It is very easy for small systems like 93L to sneak up on people who aren't expecting a stronger system.

Our next feature that will be a big story next week is invest 97L, the tropical wave that we have been talking about in the central-eastern Atlantic. This wave remains broad and void of widespread thunderstorm activity, but will likely start to ramp up a bit after it passes 50W and enters warmer waters. The models are in near unanimous consensus that this will develop near the northeast Caribbean islands and be a threat to the land areas of the southwest Atlantic during all of next week.

The track of this system should remain westerly until it passes 50W, at which point a more northerly component should be added to the motion, due to a mid-level inverted trough northwest of 97L that will be weakening the western periphery of the Bermuda high. This should bring 97L close to the northeastern Caribbean islands. The track thereafter should bring 97L close to North America, but the details of that track are still largely unknown until we actually see this system develop. Much will depend on how fast 97L strengthens on approach to the Caribbean, and whether it interacts with some of the bigger islands like Hispaniola, which would keep it weaker and farther west.

Overall, we are still a few days away from 97L significantly affecting anybody, and we still have time to watch it. If it does develop, it is likely to impact land in the southwest Atlantic basin, possibly many land masses. The pattern, which I describe in detail in today's video, is one that we have been discussing for some time would be a dangerous one during this late part of August, and we may have a storm ready to take advantage. Hopefully folks are fully prepared in case we have a hurricane baring down on land areas in 5-7 days.

We shall see what happens!

Invest 93L Visible/IR2 Floater:



Invest 93L Track Forecast Models:



Invest 97L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

93L taking a more southerly track than expected; Still watching the African wave

By: Levi32, 4:08 PM GMT on August 17, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Invest 93L remains our primary concern today, as its location in the Caribbean means it is guaranteed to hit land. 93L looks the best of its life so far, with a concentrated area of moderate convection over a well-defined mid-level circulation, though it has not yet worked its way down to the surface. The system looks pretty nice for having just gone through the central Caribbean where tropical waves are usually torn up by strong trade winds. Pressures are still not really falling though, as a buoy in the midst of 93L's circulation is only finding pressures of 1012mb, with no significant falls since yesterday. There is also still some dry air west of the circulation which may be somewhat of a hindering factor.

The biggest change this morning is in the steering currents in the western Caribbean. The flow yesterday looked to be just north of west, which I said would take 93L towards the eastern coast of the Yucatan. This flow has since bent more southward, and is now aiming WSW towards Nicaragua and Honduras. As a result, the models have all shifted south towards this region, and I must shift as well, as the steering flow is very well-established and undeniable on satellite imagery. If 93L were to rapidly strengthen during the next 24 hours, it would be able to follow the deeper-layer steering and remain on a more WNW track, passing north of Honduras and hitting Belize instead. However, rapid strengthening is not immediately likely, and 93L may run into land before reaching the area that could have promoted more rapid intensification. This is good news in a sense, as the Caribbean won't have to deal with a stronger system, but Honduras and Nicaragua may get a rare hit from what could be a tropical depression or weak tropical storm by the time 93L gets there. Belize may still be affected as well if 93L rides through Honduras and affects that entire region of central America as it moves inland. With only about 36 hours before landfall, rain is likely to be the main issue with the system.

The next system to watch closely is a well-defined African wave, now WSW of the Cape Verde Islands. This is another one of those broad, well-defined circulations that lacks thunderstorm activity, similar to the waves that spawned Don and Emily. Again, just like with those systems, the dry Saharan Desert air to the north will inhibit development in the short term, but this helps to direct the wave farther west, and once it gets past 50W, the SSTs warm up considerably, and that is when we may see some development begin. The global models are actually in impressive agreement on the general track and development schedule of this system. The UKMET has been very consistent, while the ECMWF and GFS have been jumping around a little bit on intensity. The models take the wave in the general direction of the northeast Caribbean, and eventually into the Bahamas, where it finally threatens the southeast United States. We are still talking about a wave that is 6-10 days away from significantly affecting land, and thus a lot of details cannot be known yet. However, as we have been discussing over the past several days, the overall pattern is a dangerous one that could easily bring a storm into the Caribbean islands and/or the SE U.S. coast. Thus, we should keep a close eye on this system, though it is not an immediate threat for the moment.

We shall see what happens!

Invest 93L Visible/IR2 Floater:



Invest 93L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

93L could threaten the Yucatan as a storm; African wave may be trouble down the road

By: Levi32, 4:37 PM GMT on August 16, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Invest 93L continues to fire thunderstorms in the eastern Caribbean this morning. It actually looks decent given that it is embedded in the "dead zone" of fast trade winds in the central-eastern Caribbean, which generally doesn't allow development of undeveloped systems, and 93L should be no exception here. There is no sign of a surface circulation, and pressures are riding rather high at 1012-1013mb. However, once farther west in the western Caribbean, the trade winds slow down, allowing air to pile up and rise, and thus 93L may have a chance to develop over all of that warm water. The ECMWF for a couple runs in a row now has started to develop 93L just before reaching the Yucatan Peninsula, and having support from this model, which has been conservative all year, means that this should be watched. The Texas ridge should keep 93L on a mainly westward or WNW track towards the Yucatan, and although there is a weakness in the ridge over Florida and the eastern Gulf of Mexico, 93L would have to rapidly develop into a strong hurricane to significantly feel the effects of this weakness and move northward. Therefore, a track straight into the Yucatan seems likely here, with a possible double-hit on Mexico when 93L crosses the Bay of Campeche. Interests along the eastern Yucatan coasts of Mexico and Belize should monitor this system to see if it develops in a couple of days.

A new African wave is exhibiting a defined area of low pressure just southwest of the Cape Verde Islands, and will be our next feature to watch as it journeys westward. Dry Saharan air is wrapping into this feature, but so far all of this dry air has actually been forcing these waves to develop farther west and become more threatening to land areas, due to the fact that storms that wait to develop tend to track farther west before recurving. The models are all hyped up about this system, with even the ECMWF showing its first hurricane of the season passing near the northeastern Caribbean in 6-8 days. It is a long way out to be talking about the potential track of this system if it does indeed develop, but the pattern that we have been discussing for weeks now is taking shape for the peak of the hurricane season, and a storm passing near the NE Caribbean islands could be not only a threat to them, but a threat to the United States as well down the road. We will obviously know more as more time passes, but there is concern about this pattern, and with the MJO bringing upward motion back to the Atlantic right as this peak period begins, we may be in for several threats to the U.S. and Caribbean areas during the coming weeks.

We shall see what happens!

Invest 93L Visible/IR2 Floater:



Invest 93L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 4:39 PM GMT on August 16, 2011

Permalink

Gert moving out to sea; Ex-93L flares up again as expected; New African wave to watch

By: Levi32, 4:30 PM GMT on August 15, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Tropical Storm Gert has made it up to a 60mph tropical storm, and is passing east of Bermuda today, bringing only a passing shower to them. Gert may strengthen a tad more before becoming extratropical, but as expected, is not really a dangerous storm, and is not affecting land.

Finally our long parade of weak invests and storms is over, or is it? There is a batch of convection flaring up just east of the lesser Antilles this morning, associated with a tropical wave. This is former invest 93L, which looked completely dead a couple of days ago. Remember what I said though, that this would have to be watched as it hit warmer water west of 50W as it approaches the lesser Antilles, and on through the Caribbean as well. Air is piling up in the region near the periphery of the Azores High, forcing the air to rise and create the thunderstorms that we are seeing. This has no real circulation with it and is a long way from developing, but it is easy to see my concern that despite no model support, this may have to be monitored as it gets into the Caribbean. The central-eastern Caribbean will not be friendly to ex-93L, as it normally isn't to most systems due to strong trade winds there. There is also very dry air in that region out ahead of the system. However, once into the western Caribbean, conditions may be more favorable, especially with the MJO coming back into that area of the world over the next several days, and thus ex-93L should be watched for potential mischief.

Another system coming onto the scene is a strong, well-defined tropical wave just exiting western Africa. This has dry Saharan air wrapping into it, like most strong waves that come off of the continent, but may be an issue farther west. Most of the models agree that this wave will at least be an amplified feature that will try to develop west of 50W. The ECMWF is even periodically showing this, which means a lot given that the Euro has not shown major development all season long. It will be something to keep an eye on later this week and next week.

We are just now entering the most active portion of the Atlantic hurricane season (August 15th-October 15th). We have been lucky so far with a bunch of tiny, weak systems, many of non-tropical origin, but we may not be so lucky during this peak of the season, from which the deepest and strongest tropical threats come. Hopefully everyone is prepared.

We shall see what happens!

Tropical Storm Gert Visible/IR2 Floater:



Invest 93L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 4:37 PM GMT on August 15, 2011

Permalink

Franklin develops; Reasons to keep watching 93L

By: Levi32, 5:26 PM GMT on August 13, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook

*Notice* 8-14-11: I may or may not get a video out today. Internet is down for a few hours at the dorms. The bottom line is that TD 7 may become Gert, but shouldn't significantly strengthen and is not a dangerous concern for Bermuda. Former 93L looks more alive than yesterday, and is a clear feature headed for the Caribbean. Models have dropped it, but it may still have to be monitored for the reasons outlined yesterday.



Invest 95L ended up being classified as TD #6 yesterday by the NHC, and then Franklin later on. This system does deserve the name, as it is clearly warm-core, though it is debatable whether it is still attached to the frontal boundary, in which case it would be some kind of subtropical hybrid. Either way, it would be named Franklin, and thus this is a deserved name. We have 6 named storms now, and 3 of them have been from fronts, which is interesting. Such features do not really represent the level of tropical activity in the Atlantic, but we do have them anyway.

Invest 94L and 92L may make passes close to Bermuda as they curve out to sea, and shouldn't be a significant threat to anyone, as the environment does not support significant strengthening. 94L has a circulation today, so if it pops some more convection, we may get another tropical depression. Who knows lol. It is the daughter of Emily, so persistence is to be expected from that system.

Invest 93L looks the worst of all of the systems out there today, and is barely noticeable approaching 40W. However, the system is still a clear perturbation in the flow near the monsoon trough, and is embedded in a deceptively deep layer of moisture along the monsoon trough. This could allow it to remain a defined-enough entity that we may hear more from it later. As we have been discussing, immediate development of this was never expected, and that it may wait several days before doing much. Once it gets into the warmer waters east of the lesser Antilles, we may see it try to flare up a little bit. Due to its weak state now, it looks like it will run into the Caribbean, which changes the ball game because right off the bat it means that land areas are threatened. The ocean heat content is sky high in this region, and thus it is worth keeping an eye on this if it remains defined as it enters the Caribbean. The GFS winds this up into a hurricane in the western Caribbean in 8 days.

The future track of this is still something that requires us to look 8-10 days down the road, and thus we can't know a lot of details right now. However, there are some key features showing up in the pattern. The models are in general agreement on a very strong trough over the Gulf of Alaska in 6-8 days, which argues for a pumping of the heights (ridging) over western Canada. This would tend to draw the Texas ridge west of where it has been, closer to the rockies. In turn, the weakness over the eastern seaboard between this ridge and the Atlantic ridge would shift west as well, more over the eastern gulf coast. If a storm were to come in from the east, north of the Caribbean, it wouldn't make it into the Gulf of Mexico. However, if we get a storm in the Caribbean during this time, possibly from 93L, it would tend to curve up into the gulf, something we have not seen a real chance for all season. We had Don, but we all knew that would be a weakling, and wasn't really a big deal. However, if we get a deep tropical system coming out of the Caribbean under favorable conditions, it wouldn't take much to get it to become a hurricane, and that area of the world including the gulf, Florida, the Bahamas, the Yucatan, and the Caribbean islands may have to keep a close eye on 93L if it tries to flare up in the Caribbean. For now, it is not an immediate concern, and it may never develop, but chances are it will try to sneak up on us in several days, and if it does, it may be an issue.

We shall see what happens!

Tropical Storm Franklin Visible/IR2 Floater:



Invest 93L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 3:35 PM GMT on August 14, 2011

Permalink

Four Invests - Only one may be a significant threat down the road

By: Levi32, 4:44 PM GMT on August 12, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



We have quite the train of invests out in the Atlantic today. We now have four active invests, 92L-95L. Invest 95L is along a frontal boundary just NW of Bermuda, likely baroclinically influenced, and although it has a circulation developing, probably won't deserve classification, but that will be up to the NHC. It is no threat to land.

94L is the piece that split off from Emily, and is now northeast of the Antilles, trying to come down around the Bermuda High and cause mischief a second time. Coming down around the SE flank of an upper ridge is very difficult to do, and most systems attempting that don't survive, so I still have doubts that 94L will develop significantly, but it is worth keeping a wary eye on in case it tries to pull off another performance. The ghost of Emily is very persistent, after all.

Invest 92L is southeast of 94L, and is a lot farther north than it was yesterday, now near 18N as the northern portion of the wave split off from it due to dry air and elongation. Dry air is still plaguing this system, though it is starting to move into warmer waters today. This may still have a chance at developing, but even if it does, it shouldn't get too strong. A ridge building in to its northeast should keep it moving WNW to NW for a little while, eventually recurving near the Bermuda Area, so those folks should keep an eye on this feature in case it develops.

Invest 93L is southeast of 92L, and has lost most of its convection from yesterday. As I mentioned, we shouldn't really get too excited about it immediately developing, as some models had it doing. It still lacks circulation, and it is still embedded in the monsoon trough, which does protect it from dry air, but also impedes the focusing of surface convergence (piling up of air) near the system. The fact that 93L is remaining weak is almost not good news, as it means that it could sneak farther west before gaining latitude. Thus, the Caribbean islands may need to watch 93L in case it tries to develop near their area and come into the northeast Caribbean.

The 0z ECMWF and 6z GFS actually take 93L through the entire Caribbean and into the Yucatan Peninsula in 10 days. I find these solutions to be a bit premature and perhaps too far south, but we will see how future runs treat the system. The steering features in the forecast remain the same. A sharp trough off the eastern seaboard during the next 4 days should recurve 92L, but will lift out quickly as most troughs have done in the western Atlantic so far this season. Once it lifts out, ridging develops over southeastern Canada, but the weakness between the Texas ridge and Atlantic ridge still remains over the eastern seaboard. This results in yet another fragile pattern that is capable of recurving some storms, like 92L, but can also bring storms to the coast if they come in far enough south, as 93L might. This persistent weakness over the east is why I think the model runs bringing 93L into the Yucatan may be a bit too far south, but if 93L remains as weak as it is now for the next 6-7 days, such runs illustrate the potential danger for it to get right into all of those land areas in the Caribbean region. The pattern supports mischief close to land, and thus we should keep a close eye on 93L in case it develops. The eastern Caribbean islands will have to watch this system first, though it is not much of a worry right now unless it starts to wind up before getting there. It may never develop either, but with the MJO coming back to our basin as it chugs westward, and with the time of year that we are in, chances are it will try to wind up down the road and threaten somebody.

We shall see what happens!

Invest 92L Visible/IR2 Floater:



Invest 92L Track Forecast Models:



Invest 93L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

92L more likely to recurve east of the U.S.; Jury still out on 93L

By: Levi32, 3:20 PM GMT on August 11, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



We are continuing to watch our two invests in the eastern Atlantic, the only real features of interest in the Atlantic right now. 92L has lost the closed circulation that it had yesterday, and is now a bit more broad and elongated. It is a negatively-tilted tropical wave that is wrapping in dry air from the west, which will continue to be a problem in the near term. Later on after hitting warmer waters west of 50W, we may hear some more from 92L.

Just behind 92L is 93L, still embedded in the monsoon trough, and firing some convection. Persistence of this convection will be key to forecasting its potential development. Right now I see little circulation with 93L, and we need to wait a little bit before declaring it to be a guaranteed development, despite some of the models jumping all over it. It may take its time developing, perhaps not as long as 92L, but it shouldn't be immediate.

The track of these two entities again falls in an interesting and dynamic pattern. A strong trough over the eastern seaboard and western Atlantic will be in place in 5-6 days when 92L is forecasted to arrive on the scene. This trough will be trying to lift out fast, but given the current timing forecasted by the models, 92L looks like it will make it there too early to miss the trough, and should get caught up in it and recurve east of the U.S., a possible threat to only Bermuda. If the timing is off by a bit, 92L may get farther west than that, but at this time I believe recurvature east of the U.S. is more likely. Any changes to this philosophy will be highlighted immediately.

93L is a few degrees farther south than 92L, and thus should track farther west with smaller latitude gains before reaching 60W. The northeast Caribbean may have to monitor this system if it stays far enough south. In the long-term, the trough that recurves 92L will be lifting out, causing a more zonal (flat) flow to develop over southeast Canada, with a weakness over the eastern seaboard between the Texas ridge and the Atlantic ridge. Such a pattern could try to direct 93L up the eastern seaboard with a possible landfall if it is a storm at that time. It is still a very long way out, but the pattern could support a threat to the coast, and thus this setup should be monitored closely if 93L develops.

We shall see what happens!

Invest 92L Visible/IR2 Floater:



Invest 92L Track Forecast Models:



Invest 93L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 3:37 PM GMT on August 11, 2011

Permalink

1-2 Punch Coming from the Eastern Atlantic

By: Levi32, 3:01 PM GMT on August 10, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



The tropical Atlantic remains mostly quiet today, though it will not remain that way for long. Invest 92L has developed into a well-defined area of low pressure in the eastern Atlantic near 13N, 30W. It is already a closed low, and thus could become a tropical depression as soon as it gains sufficient thunderstorm activity. Dry air getting entrained from the west will hold this system down for a while, inhibi ting significant development. However, after the system gets to 50W in a few days, the water warms by 1-2 degrees Celsius, and that is when we could see 92L try to take off as it mixes out some of that dry air. A tropical wave behind 92L is just leaving Africa and is also developed by some of the models, and this one should be watched carefully as well. A 1-2 punch is about to come across the Atlantic.

The long-term track of 92L will as always depend a lot on timing, but the models favor a trough over the eastern seaboard that should recurve 92L before reaching the United States. However, 92L will be moving towards the trough near the time when it starts to lift out, which is the same story we had with pre-Don and Emily. As with all of the troughs this year that have tried to dig into the western Atlantic, this one will be lifting out very fast, and even a small delay in 92L's westward progress could cause the ridge to build in from its east and get it closer to the eastern seaboard. The ECMWF from last night shows this well, getting 92L within 150 miles of the U.S. coast in 8-9 days. A very similar situation is what brought Hurricane Bertha to shore in July 1996. She developed farther south, though.

This is all part of a pattern that is showing up on the ensembles, where blocking ridging is developing over southeastern Canada during the 8-15 day period. This is a prime signature of a pattern that can bring storms towards the United States. 92L may get there too early and be forced to recurve, but the one behind it may be more of a threat, as it is tracking farther south, and will be coming in after the trough has lifted out of the western Atlantic. The models will likely trend too far north and east with both of these systems initially, as they have done with everything else so far this season. For these reasons, both of these features should be watched carefully next week. A 1-2 punch is coming, and both of them could be storms that have at least some potential of threatening someone down the road.

We shall see what happens!

Invest 92L Visible/IR2 Floater:



Invest 92L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

Atlantic quiet for now - A look at Texas Drought Analogs

By: Levi32, 1:19 PM GMT on August 08, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



The tropical Atlantic is fairly quiet today. We do have a bit of a downward MJO pulse bringing sinking motion and dry air, which is keeping activity low for the moment. We are watching a potent tropical wave south of the Cape Verde Islands which will be coming westward, and the GFS was previously developing this wave, though it has since backed off. Regardless, the wave should be watched in case it can get rid of the dry air around it once it gets farther west. More strong tropical waves behind it will also have to be watched as they come off. The wave train is starting to heat up a lot as we head towards Cape Verde season.

In today's video I show analogs to Texas' big drought that is currently ongoing, and how the hurricane seasons compare. It turns out that the Texas drought analogs are just one more piece to the puzzle that favors potential hurricane impacts on the U.S. east coast and Caribbean islands this year. Hopefully folks are prepared for whatever this season brings us.

We shall see what happens!

Invest 92L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

Emily dissipates over Haiti - little threat to Bahamas/Florida; Watching for Franklin

By: Levi32, 1:35 PM GMT on August 05, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



We are now watching the remnants of what was Tropical Storm Emily, now north of eastern Cuba. The area of greatest cyclonic turning is right there where Emily probably would have been on its way towards the northern Bahamas had it remained a storm. Emily was ripped apart by the mountains of Hispaniola. We knew that full dissipation of the low-level center was very possible during this crossing, and I had mentioned it several times. The forecast assumed that regeneration would occur for the sake of illustrating what the potential impacts could be in the Bahamas and south Florida, but fortunately we won't have to deal with that. Florida could have used the rain, but oh well. Regeneration of Emily is still possible, though if it occurs, it will likely wait until after she is already starting to turn out to sea, and the Bahamas and perhaps southern Florida can expect a few showers, but that's about it. The area will be watched closely, as it is the equivalent of having a very strong tropical wave moving through.

Next comes Franklin, and he may be of Cape Verde origin, as the GFS has been hinting at developing a wave currently over western Africa during the next several days as it comes out over the Atlantic and travels westward. The ECMWF also hints at mischief in the eastern Atlantic, but later than the GFS, perhaps showing the next wave in line over central Africa. It is August, and the Cape Verde season is almost upon us. We will be watching the wave train closely, as the steering pattern supports it coming pretty far west, and the GFS has been taking these waves into the Caribbean and Bahamas areas in the long-range. We will be watching closely for the possibility of Franklin developing from one of these waves over the next week or two.

In today's video I talk a little bit about this summer's heat wave and how the orientation of the axis of greatest heat plays a role in the hurricane season, and how this year compares to seasons that saw many hurricane landfalls here in the United States.

We shall see what happens!

Tropical Storm Emily Visible/IR2 Floater (Click for loop):



Tropical Storm Emily Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

Emily still weak but better organized - dumping heavy rains on Hispaniola

By: Levi32, 1:39 PM GMT on August 04, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Emily continues to churn away in the Caribbean just south of Hispaniola, and is slightly better organized than last night. The recon recently found a pressure of 1006mb, no lower than last night, but the surface center is now located underneath the deep thunderstorms, something that Emily has been struggling to accomplish ever since she formed. This indicates that wind shear is lessening over the storm, and that Emily is now becoming more vertically stacked, which could allow some gradual deepening to begin before she interacts with Haiti and eastern Cuba later tonight and tomorrow. If Emily survives crossing the mountainous regions of Haiti's southwestern Peninsula and eastern Cuba, the upper-level environment should improve over the Bahamas, as an upper low over the western Caribbean, which split off from the trough over the western Atlantic, will be backing away and allowing Emily's upper ridge to expand more over her, allowing her to "breathe" better. Dry air will still be an issue for Emily as subsidence continues off of the SE US coast, associated with a ridge over the Carolinas. Emily's ridge will have to merge with this ridge over time, something that Don failed to do in the Gulf of Mexico, and was thus sheared until landfall. Emily could have better luck with this task, and although the upper environment will not be perfect, it will likely be the best of her lifetime, and thus gradual strengthening is possible in the Bahamas if she is still intact by that point. We will have a better idea of Emily's intensity near Florida and the northern Bahamas after we see how she deals with Haiti's mountains, but given the small amount of time that she will have before reaching her closest pass to Florida (or a landfall), a hurricane is probably unlikely.

Emily's track philosophy remains the same as it has been all week. An upper trough over the western Atlantic is currently lifting out to the northeast, leaving a trailing weakness behind between the southern U.S. ridge and the Atlantic ridge. Emily is moving very slowly at the moment due to weak steering currents as she nears this weakness. Unfortunately, flooding is becoming a bigger problem in Hispaniola as Emily remains parked south of them, continuing to poor rain into Haiti and the Dominican Republic, which routinely experience loss of life from the flooding that tropical systems cause. We hope and pray that damages are minimal here with Emily, but the heavy rain is long from over. Emily should move WNW to NW into the weakness today, crossing over the SW peninsula of Haiti and eastern Cuba, eventually making it into the Bahamas area by tomorrow afternoon. As the trough over the western Atlantic continues to lift out, the Atlantic ridge will start building in to the northeast of Emily, closing the weakness and nudging her path back to the left for a time. This should take Emily very close to south Florida, and my track has Emily within 100 miles of the coastline, if not a landfall. After today, we will know more about the fine detail of whether this will actually make landfall or skirt the Florida coast just offshore. The 06z GFS ensembles from this morning illustrate the kind of track that I expect here. After passing close to Florida or making a landfall, acceleration to the north and the northeast is expected as Emily finds the weakness between the two ridges and gets pulled into the westerlies. The other southeast U.S. states should keep an eye on Emily, but again, the pattern favors the storm curving quickly away from shore, impacting only Florida.

Overall, we have a still weak storm currently moving slowly, with some uncertainty in her future intensity until we see how she deals with the mountains of Haiti and eastern Cuba. The track should take this very close to Florida, with the Bahamas having to deal with her first. The time allotted before a potential landfall shouldn't allow a whole ton of strengthening, but some intensification is possible if Emily remains intact in the Bahamas. Please heed the warnings of the NHC and your local NWS office as this storm approaches. If a landfall in Florida is deemed by the NHC to be likely, watches may go up for south Florida later tonight.

We shall see what happens!

Official NHC Forecast Track for Emily:



Official NHC Public Advisory for Emily:

000
WTNT35 KNHC 041139
TCPAT5

BULLETIN
TROPICAL STORM EMILY INTERMEDIATE ADVISORY NUMBER 11A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052011
800 AM EDT THU AUG 04 2011

...EMILY MEANDERING JUST SOUTH OF HISPANIOLA...HEAVY RAINS SHOULD
CONTINUE...


SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...17.1N 71.8W
ABOUT 40 MI...65 KM SSW OF ISLA BEATA DOMINICAN REPUBLIC
ABOUT 105 MI...170 KM SSE OF PORT AU PRINCE HAITI
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE SOUTHERN COAST OF THE DOMINICAN REPUBLIC FROM CABO ENGANO
WESTWARD TO THE SOUTHERN BORDER WITH HAITI
* THE NORTHERN COAST OF THE DOMINICAN REPUBLIC FROM CABO FRANCIS
VIEJO WESTWARD TO THE NORTHERN BORDER WITH HAITI
* HAITI
* SOUTHEASTERN AND CENTRAL BAHAMAS...AND TURKS AND CAICOS ISLANDS
* GUANTANAMO AND HOLGUIN PROVINCES IN EASTERN CUBA

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* NORTHWESTERN BAHAMAS

INTERESTS ELSEWHERE IN EAST-CENTRAL CUBA AND IN SOUTH FLORIDA SHOULD
MONITOR THE PROGRESS OF EMILY.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 AM EDT...1200 UTC...THE CENTER OF TROPICAL STORM EMILY WAS
LOCATED BY AN AIR FORCE RECONNAISSANCE PLANE NEAR LATITUDE 17.1
NORTH...LONGITUDE 71.8 WEST. EMILY HAS BEEN MEANDERING DURING THE
PAST FEW HOURS BUT IS EXPECTED TO RESUME A WEST-NORTHWEST TRACK
NEAR 7 MPH...11 KM/H...THIS MORNING. A TURN TOWARD THE NORTHWEST
WITH AN INCREASE IN FORWARD SPEED IS EXPECTED DURING THE NEXT DAY
OR SO. ON THIS TRACK...THE CENTER OF EMILY WILL MOVE ACROSS THE
SOUTHWESTERN PENINSULA OF HAITI LATER TODAY AND MOVE OVER EXTREME
EASTERN CUBA TONIGHT OR EARLY FRIDAY.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 50 MPH...85 KM/H...WITH HIGHER
GUSTS. SOME WEAKENING IS POSSIBLE DURING THE NEXT 24 TO 36 HOURS AS
EMILY INTERACTS WITH THE HIGH TERRAIN OF HAITI AND EASTERN CUBA.
SOME RE-STRENGTHENING IS POSSIBLE WHEN THE CYCLONE MOVES OVER THE
BAHAMAS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115 MILES...185 KM
MAINLY TO THE NORTH AND EAST OF THE CENTER.

THE MINIMUM CENTRAL PRESSURE RECENTLY REPORTED BY AN AIR FORCE
RECONNAISSANCE PLANE WAS 1005 MB...29.68 INCHES.


HAZARDS AFFECTING LAND
----------------------
RAINFALL...EMILY IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS
OF 6 TO 12 INCHES WITH ISOLATED AMOUNTS OF 20 INCHES POSSIBLE
OVER THE DOMINICAN REPUBLIC AND HAITI. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. TOTAL RAIN
ACCUMULATIONS OF 2 TO 4 INCHES ARE EXPECTED IN THE SOUTHEASTERN AND
CENTRAL BAHAMAS...AND THE TURKS AND CAICOS ISLANDS. EMILY IS
EXPECTED TO PRODUCE ADDITIONAL RAIN ACCUMULATIONS OF 1 TO 2 INCHES
IN PUERTO RICO.

WIND...TROPICAL STORM CONDITIONS ARE LIKELY OCCURRING OVER PORTIONS
OF THE DOMINICAN REPUBLIC...PRIMARILY ALONG THE SOUTHERN
COAST...AND WILL LIKELY SPREAD OVER HAITI TODAY. TROPICAL STORM
CONDITIONS ARE EXPECTED TO REACH EXTREME EASTERN CUBA...THE
SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS TONIGHT...AND
THE CENTRAL BAHAMAS ON FRIDAY. TROPICAL STORM CONDITIONS ARE
POSSIBLE IN THE NORTHWESTERN BAHAMAS EARLY SATURDAY.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY 1 TO 3 FEET
ABOVE NORMAL TIDE LEVELS IN THE TROPICAL STORM WARNING AREA. NEAR
THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS
WAVES.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 AM EDT.

$$
FORECASTER AVILA


Tropical Storm Emily Visible/IR2 Floater (Click for loop):



Tropical Storm Emily Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 2:20 PM GMT on August 04, 2011

Permalink

Emily weaker and moving farther west, may have a higher chance of impacting Florida

By: Levi32, 3:28 PM GMT on August 03, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Tropical Storm Emily continues to struggle with organization over the eastern Caribbean. Deep convection has been firing for 60 hours straight now, but always east of the low-level center, which has now become fully exposed to the west of the convective activity due to dry air to the northwest of the storm and westerly wind shear. The center is probably the most well-defined that it has ever been, but as long as it is sheared and decoupled from the mid-level part of the storm, it will remain weak. No significant strengthening is likely before Emily begins crossing the Caribbean islands.

The big question this morning is when Emily will finally make her turn northwestward. The storm, now weaker than it was forecasted to be near Hispaniola, and with an exposed surface center, is continuing to move westward, despite the forecast for it to be turning towards the Dominican Republic right now. Given its present movement, it may very well miss the DR altogether, and may try to curve up over Haiti and eastern Cuba instead. This is only logical given the weaker state of the system and the fact that it is decoupled from the mid-level circulation. Thus, the forecast must be adjusted westward. Emily should eventually make the turn due to the trough over the Bahamas, and once she does, she will likely have to move over the tall mountains of Haiti or eastern Cuba, or both. A naked surface swirl moving over these mountains would literally disappear, making it entirely up to the mid-level circulation to get across to the north of these islands and regenerate the low-level center. This may or may not happen, and Emily could very well die after attempting such a crossing. For now, we will assume that she will eventually try to regenerate on the other side under slightly more favorable conditions.

The track after getting north of the Caribbean should bend back towards the WNW as the upper trough lifts out, allowing ridging to build back in to the northeast of the cyclone, taking her near the northern Bahamas and southeast Florida. Yesterday I had the track within 200 miles of the Florida coast, but that may come even closer if Emily curves up a lot farther west than forecast, and Florida could have a higher chance of seeing a landfall from this system. Southeast Florida and the northern Bahamas remain the most likely land areas to be affected by Emily after she moves north of the Caribbean, as the flow aloft does not support a sweeping curve that could affect the Carolinas as Emily recurves out. Although the other SE US states should monitor the situation, a landfall north of Florida is unlikely.

The intensity north of the Caribbean, assuming Emily survives, should consist of gradual regeneration and strengthening as Emily moves northwest over the Bahamas. With the tail-end of the west Atlantic trough splitting off and retrograding westward over the Gulf of Mexico, the area should be ventilated, and Emily's upper anticyclone should be allowed to expand over the Bahamas with time. The big negative still in play will be the upper ridge over the Carolinas, which will bring subsidence and dry air off the southeast U.S. coastline, impeding Emily's intensification. Eventually the Carolinas high and Emily's high will integrate with each other, but dry air will remain a problem even as shear relaxes. Intensification into a hurricane before moving into the northern Bahamas or southern Florida is unlikely. Her eventual intensity on the way out to sea will be determined by how she fares after crossing the Caribbean islands and whether she moves over Florida.

Overall, we have a weaker system this morning that is trying to move farther west, and may have a higher chance of impacting Florida before recurving out later this weekend. The Bahamas are still the most likely to see Emily's effects before anyone else north of the Caribbean. Hispaniola and eastern Cuba may have to deal with heavy rains and the flooding that usually comes with them.

We shall see what happens!


Official NHC Forecast Track for Emily:



Official NHC Public Advisory for Emily:

000
WTNT35 KNHC 031449
TCPAT5

BULLETIN
TROPICAL STORM EMILY ADVISORY NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052011
1100 AM AST WED AUG 03 2011

...EMILY BECOMING DISORGANIZED WHILE MOVING WESTWARD...STILL
EXPECTED TO DUMP HEAVY RAINS OVER HISPANIOLA...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...16.7N 69.7W
ABOUT 125 MI...200 KM S OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF CUBA HAS ISSUED A TROPICAL STORM WARNING FOR
THE PROVINCES OF GUANTANAMO AND HOLGUIN IN EASTERN CUBA.

THE TROPICAL STORM WARNING FOR PUERTO RICO...VIEQUES AND CULEBRA HAS
BEEN DISCONTINUED.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE DOMINICAN REPUBLIC
* HAITI
* SOUTHEAST BAHAMAS AND TURKS AND CAICOS ISLANDS
* GUANTANAMO AND HOLGUIN PROVINCES IN EASTERN CUBA

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* CENTRAL BAHAMAS

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL
WEATHER SERVICE FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO
YOUR AREA OUTSIDE THE UNITED STATES...PLEASE MONITOR PRODUCTS
ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL STORM EMILY WAS
LOCATED NEAR LATITUDE 16.7 NORTH...LONGITUDE 69.7 WEST. EMILY IS
MOVING TOWARD THE WEST NEAR 14 MPH...22 KM/H. A TURN TO THE
NORTHWEST IS EXPECTED LATER TODAY. ON THE FORECAST TRACK...THE
CENTER OF EMILY WILL MOVE ACROSS WESTERN HISPANIOLA LATE TODAY AND
TONIGHT AND INTO THE SOUTHEASTERN BAHAMAS AND TURKS AND CAICOS
ISLANDS ON THURSDAY.

MAXIMUM SUSTAINED WINDS ARE 50 MPH...85 KM/H...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST TODAY BEFORE THE
CENTER REACHES THE WESTERN PORTION OF HISPANIOLA...FOLLOWED BY
WEAKENING AS THE CENTER MOVES OVER THE HIGH TERRAIN. SOME
RE-STRENGTHENING IS POSSIBLE AFTER THE CENTER MOVES AWAY FROM
HISPANIOLA.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115 MILES...185 KM
TO THE NORTH AND EAST OF THE THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS SHOULD BEGIN TO SPREAD INTO
PORTIONS OF THE DOMINICAN REPUBLIC AND HAITI LATER TODAY AND
TONIGHT. TROPICAL STORM CONDITIONS ARE EXPECTED TO SPREAD OVER
EXTREME EASTERN CUBA...THE SOUTHEAST BAHAMAS AND THE TURKS AND
CAICOS ISLANDS ON THURSDAY. TROPICAL STORM CONDITIONS ARE POSSIBLE
IN THE CENTRAL BAHAMAS THURSDAY NIGHT.

RAINFALL...EMILY IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS
OF 6 TO 10 INCHES IN PUERTO RICO WITH ISOLATED AMOUNTS OF 12 INCHES.
RAINFALL ACCUMULATIONS OF 6-12 INCHES WITH ISOLATED AMOUNTS OF 20
INCHES ARE POSSIBLE OVER THE DOMINICAN REPUBLIC AND HAITI. THESE
RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.
TOTAL RAIN ACCUMULATIONS OF 2 TO 4 INCHES ARE EXPECTED IN THE
SOUTHEAST BAHAMAS AND TURKS AND CAICOS.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY 1 TO 2 FEET
ABOVE NORMAL TIDE LEVELS IN THE TROPICAL STORM WARNING AREA. NEAR
THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS
WAVES.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM AST.
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER AVILA


Tropical Storm Emily Visible/IR2 Floater (Click for loop):



Tropical Storm Emily Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 3:29 PM GMT on August 03, 2011

Permalink

Emily struggling to organize - will likely hit the Dominican Republic first

By: Levi32, 1:49 PM GMT on August 02, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Tropical Storm Emily has developed, and is now west of the Antilles islands in the eastern Caribbean. Emily is a 40mph tropical storm, with fairly unimpressive winds coming in from this morning's recon. A pressure of 1007mb was found, indicating no real strengthening since yesterday. The center remains ill-defined both in recon reports and Antilles Radar. Convection continues to fire in strong bursts near and east of the center, but dry air wrapping into the storm seems to be preventing intensification for the moment, and this will continue to be a problem over the next couple days. An upper trough oriented zonally (west to east) north of the Caribbean is also limiting Emily's outflow and moderately shearing her north side, which should also limit intensification. A plus for Emily is that the center is located farther east than the NHC thought, meaning that Emily is moving slower than expected, which might help her to strengthen gradually.

A strong trough is digging into the western Atlantic right now, which should induce Emily to make a northward turn today and tomorrow, bringing the storm likely into the Dominican Republic. A moderate tropical storm of 50-60mph is possible before Emily makes landfall there in about 36 hours. The biggest issue with Emily's forecast will be whether she survives the crossing of Hispaniola, and how strong she may get if she regenerates on the other side. The nearly 10000-ft tall mountains on the island can completely destroy tropical cyclones. They also extract deadly rains from even the weakest of systems, threatening the population there. Weaker systems have more potential to strengthen after making the crossing, if they survive, so if Emily makes it, some strengthening may be likely on the other side.

The track after Hispaniola will partially depend on Emily's strength as well, so there is a large degree of uncertainty here, as it is nearly impossible to predict how any particular tropical cyclone will react to the crossing of Hispaniola. The trough that will bring Emily north of the Caribbean will be lifting out during the 3-4 day period, allowing the Atlantic ridge to try to build in to the north of Emily. This should result in a slight nudge back to the WNW, allowing Emily to move near the Bahamas and get pretty close to Florida. Eventually, with a WNW flow aloft coming off of the eastern seaboard, a shortwave will likely take Emily on a sharp turn northeastward and out to sea. Whether Emily makes landfall over southeastern Florida before this turn occurs is something that simply cannot be guaranteed at this point, and it will likely be pretty close, which is all I can say for now. Florida should be on the watch for this system. The other southeast U.S. states should watch as well, but the pattern would make it extremely difficult for Emily to make landfall anywhere but south Florida, so I doubt that we will see a threat for a strike anywhere else. This is a particularly difficult system to forecast, so folks all along the potential path should be preparing, even if the forecast track doesn't aim right at you right now.

We shall see what happens!

Official NHC Forecast Track for Emily:



Official NHC Public Advisory for Emily:

000
WTNT35 KNHC 021151
TCPAT5

BULLETIN
TROPICAL STORM EMILY INTERMEDIATE ADVISORY NUMBER 3A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052011
800 AM AST TUE AUG 02 2011

...AIR FORCE PLANE FINDS EMILY STILL POORLY ORGANIZED...

SUMMARY OF 800 AM AST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...15.3N 63.7W
ABOUT 265 MI...425 KM SE OF SAN JUAN PUERTO RICO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF ANTIGUA AND BARBUDA HAS DISCONTINUED THE TROPICAL
STORM WATCH FOR ANTIGUA...MONTSERRAT...ST. KITTS...AND NEVIS.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* GUADELOUPE...DESIRADE...LES SAINTES...AND MARIE GALANTE
* PUERTO RICO...VIEQUES AND CULEBRA
* THE DOMINICAN REPUBLIC

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* U.S. VIRGIN ISLANDS
* HAITI

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
DATA FROM A RECONNAISSANCE PLANE INDICATE THAT EMILY WAS A LITTLE
BIT TO THE SOUTHEAST THAN PREVIOUSLY ESTIMATED. AT 800 AM AST...
1200 UTC...THE CENTER OF TROPICAL STORM EMILY WAS LOCATED NEAR
LATITUDE 15.3 NORTH...LONGITUDE 63.7 WEST. EMILY HAS SLOWED DOWN
AND IS NOW MOVING TOWARD THE WEST NEAR 14 MPH...22 KM/H. A TURN
TOWARD THE WEST-NORTHWEST WITH A GRADUAL DECREASE IN FORWARD SPEED
IS EXPECTED DURING THE NEXT 48 HOURS. ON THE FORECAST TRACK...THE
CENTER OF EMILY WILL MOVE ACROSS THE NORTHEASTERN CARIBBEAN SEA
TODAY...AND APPROACH HISPANIOLA TONIGHT AND WEDNESDAY.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 40 MPH...65 KM/H...WITH HIGHER
GUSTS. SOME SLOW STRENGTHENING IS POSSIBLE OVER THE NEXT DAY OR SO
BEFORE EMILY INTERACTS WITH LAND.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM
FROM THE CENTER.

MINIMUM CENTRAL PRESSURE REPORTED BY THE AIR FORCE RECONNAISSANCE
AIRCRAFT WAS 1007 MB...29.74 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE LIKELY OCCURRING OVER PORTIONS
OF THE WARNING AREA IN THE LEEWARD ISLANDS. TROPICAL STORM
CONDITIONS ARE EXPECTED IN PUERTO RICO...CULEBRA...AND VIEQUES
LATER TODAY...AND IN THE DOMINICAN REPUBLIC BY TONIGHT. TROPICAL
STORM CONDITIONS ARE POSSIBLE IN THE U.S. VIRGIN ISLANDS LATER THIS
MORNING...AND IN HAITI BY WEDNESDAY.

RAINFALL...EMILY IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS
OF 2 TO 4 INCHES IN THE NORTHERN WINDWARD ISLANDS AND LEEWARD
ISLANDS. TOTAL RAIN ACCUMULATIONS OF 4 TO 6 INCHES ARE EXPECTED IN
PUERTO RICO AND THE DOMINICAN REPUBLIC WITH ISOLATED MAXIMUM
AMOUNTS OF 10 INCHES POSSIBLE. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES IN AREAS OF
MOUNTAINOUS TERRAIN.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY 1 TO 2 FEET
ABOVE NORMAL TIDE LEVELS IN THE TROPICAL STORM WARNING AREA. NEAR
THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS
WAVES.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 AM AST.

$$
FORECASTER AVILA/BERG

Invest 91L Visible/IR2 Floater (Click for loop):



Invest 91L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Updated: 1:50 PM GMT on August 02, 2011

Permalink

91L struggling to develop - Could be a threat to Florida after the Caribbean/Bahamas

By: Levi32, 1:50 PM GMT on August 01, 2011

Please note that these tidbits do NOT reflect the official forecasts of the National Hurricane Center, and should not be taken as such. While tropical cyclones exist in the Atlantic, the official NHC forecasts will be posted in the lower part of this blog. Please refer to those when making decisions, and heed the advisories and evacuation statements of your local National Weather Service Office.

If you can, playing the video in HD makes it much easier to see things. The video will play in low quality by default. If HD quality isn't available, then it will be in a few minutes. Let me know if you have problems with the video, and please feel free to ask me any questions regarding what I talk about in these tidbits, or about the weather in general. You can post in either of my blogs or on Youtube. I will do my best to answer. Thanks for stopping by!

Find me on Youtube          Find me on Facebook



Invest 91L continues to play with our minds today. After looking pretty healthy when the weekend began, the system became very complicated yesterday, and then after looking better last night, has revealed more complexity this morning. Recon data shows that no closed circulation has developed yet, and pressures are higher than they were in the area. A broad circulation of low pressure exists southwest of the main convective area. This is the secondary western circulation that had developed yesterday, and has now detached from the tropical wave that kept going westward and passed over Puerto Rico last night. The old main circulation is mainly mid-level, and is associated with the convective blob east of Martinique. A finger of low pressure extends up towards this blob, but again, there is no closed circulation at this time. Some shearing is also now going on from the south of 91L, due to a mass of convection associated with the ITCZ north of South America. This shear from the south may be holding 91L's convection a bit north of the low center. The shear should gradually relax over the next couple of days as 91L moves westward away from the active ITCZ in the central Atlantic.

Invest 91L should eventually develop a consolidated circulation and become a tropical depression or storm, but at this point it's anybody's guess as to when that will be. This system has decided to be very strange. The NHC is fairly confused by it as well, since they have had the system at 90%-100% chance for development for over 2 days now.

The good news for the islands and Puerto Rico is that since this system is struggling to develop, the Lesser Antilles islands won't be dealing with a strong tropical cyclone, and Puerto Rico might be spared, as a weaker system is more likely to track to the south of the island, and hit Hispaniola instead. By no means should PR residents let their guard down, as things can still change, especially when we have no defined center yet with 91L. However, it is appearing more likely, given the weaker state of 91L, that Hispaniola will get the hit instead. This is not great news, because even if 91L is still an invest at that point, even a tropical disturbance can be very deadly there, as the tall mountains extract copious amounts of heavy rain. These mountains would also knock down 91L considerably and weaken it as it heavily disrupts its circulation.

Looking at the long-term track, we are continuing to monitor the possibility of this system affecting Florida down the road. We have been talking for a couple of days now about how the pattern could easily support a track that approaches or moves over south Florida before recurving out sharply to the northeast. The reason for this is that a trough moving over the eastern United States will be moving over the western Atlantic to bring 91L north of the Caribbean islands, but will then be leaving fairly quickly, allowing the Atlantic ridge to build back in north of 91L. This will result in a WNW track, likely over the Bahamas, possibly right into south Florida. Again, the pattern with a NW jetstream cutting across the eastern U.S. does not favor a sweeping recurve that strikes Cape Hatteras, and although the other southeast U.S. states should keep a close eye on this, Florida would be the most likely to get the hit in this pattern. The Texas ridge would block a significant move into the Gulf of Mexico, and thus a shortwave would have to come down and take 91L sharply northeast out to sea after moving over Florida, possibly pretty slowly under weak steering currents, which would catch them up on some rainfall if the situation turned out that way.

Overall, we have a struggling system that will spare the lesser Antilles a hit from a tropical cyclone, but Hispaniola may still have to deal with one in 2-3 days. Puerto Rico is still in the mix as well, and shouldn't let their guard down, but a weaker system has a greater chance to avoid them. Florida has a greater chance to be affected down the road, although I still want to see how 91L looks near Hispaniola/PR before making a call there. The models have continuously shifted west, as we figured they would have to in this kind of a pattern. Florida should monitor the progress of this system.

We shall see what happens!

Invest 91L Visible/IR2 Floater (Click for loop):



Invest 91L Track Forecast Models:



Caribbean/East Pacific Visible/IR2 Satellite (click image for loop):



Central Atlantic Visible/IR2 Satellite (click image for loop):



Atlantic Tropical Surface Analysis:



200mb Vertical Velocity (green areas represent upward motion associated with the MJO):






Permalink

About Levi32

Levi Cowan has been tracking tropical systems since 2002, and is currently working on his bachelor's degree in physics at UAF.

Local Weather

Light Rain
54 °F
Light Rain

Levi32's Recent Photos

Hurricane Mitch

Recommended Links

Personal Weather Stations

MesoWest NERRS METEOROLOGICAL SITE AT KAC AK US
Fritz Creek, AK
Elevation: 32 ft
Temperature: 55.0 °F
Dew Point: 52.0 °F
Humidity: 91%
Wind: 4.0 mph from the NE
Wind Gust: 5.0 mph
Updated: 12:30 AM AKDT on August 27, 2014
Overlooking Peterson Bay
Homer, AK
Elevation: 27 ft
Temperature: 158.0 °F
Dew Point: 0.0 °F
Humidity: 0%
Wind: Calm
Wind Gust: 0.0 mph
Updated: 1:38 AM AKDT on August 27, 2014
RAWS HOMER AK US
Homer, AK
Elevation: 854 ft
Temperature: 49.0 °F
Dew Point: 48.0 °F
Humidity: 95%
Wind: 3.0 mph from the West
Wind Gust: 4.0 mph
Updated: 12:54 AM AKDT on August 27, 2014

About Personal Weather Stations