Little change to Isaac, but intensification coming; Joyce forms

By: Dr. Jeff Masters , 3:13 PM GMT on August 23, 2012

Share this Blog
49
+

Tropical Storm Isaac is a large and impressive-looking storm on satellite images, but data from the Hurricane Hunters reveal that Isaac remains a minimal-strength tropical storm with 40 mph winds, as it heads westward across the Eastern Caribbean. An Air Force Reserve hurricane hunter aircraft which completed its mission into Isaac at 8 am EDT found top winds at the surface near 40 mph, and highest winds at their 5,000 foot flight level of 47 mph. A NOAA hurricane hunter aircraft flying at 10,000 feet has found top winds of 47 mph at that altitude. The Hurricane Hunters found a broad area of light winds with a central pressure of 1003 mb. The aircraft did not observe an eyewall trying to form, and recent microwave satellite images also show no signs of an eyewall forming. There does not appear to be much in the way of dry air near the core of Isaac, as seen on water vapor satellite loops, which is a big switch from what we've seen previously. Visible satellite loops show that Isaac has a much more symmetric circular cloud pattern, and has developed a Central Dense Overcast (CDO) of high cirrus clouds, the hallmark of an intensifying storm. These clouds have very cold cloud tops, indicating that the updrafts creating them are quite strong. An analysis of upper level winds from the University of Wisconsin CIMSS shows that an upper-level pattern of outflow supportive of significant strengthening has developed this morning, with an upper-level outflow channel now well-established to the north, and a new outflow channel opening to the south. Radar imagery from Puerto Rico shows some weak low-level spiral bands that are slowing intensifying and becoming more organized.


Figure 1. Morning radar image of Isaac taken from the Puerto Rico radar. Isaac's rain bands are weak, but are starting to take on a more spiraling shape.

Intensity forecast for Isaac
Isaac has consistently confounded predictions that it would intensify, but all the potential factors inhibiting intensification seem to have diminished to the point where intensification has to occur. Wind shear is low, 5 - 10 knots, and ocean temperatures are warm, 29°C, and these warm waters extend to great depth, giving the storm a high total heat content to work with. These factors, combined with the favorable upper-level outflow pattern and more symmetric cloud pattern, support intensification, and all of the intensity models except the HWRF model predict intensification of Isaac to a strong tropical storm or Category 1 hurricane by Friday afternoon. The latest 8 am EDT run of the SHIPS model predicts that wind shear will be light to moderate, 5 - 15 knots, for the next five days. The 11 am EDT wind probability forecast from NHC predicted a 34% chance that Isaac will become a hurricane by Friday afternoon, and a 6% chance it will be a Category 2 or stronger hurricane then. By Friday afternoon, Isaac will likely be close enough to Southwest Haiti that the inner core will be disrupted, and the storm will likely be a 45 - 55 mph tropical storm on Saturday and Sunday as it moves over Cuba. Once Isaac pops off the coast of Cuba into the Florida Straits, it will be over very warm waters of 31 - 32°C (88 - 90°F), wind shear will be light to moderate, and the upper-level wind pattern favorable for intensification, with low wind shear due to an upper-level anticyclone over the storm. It will probably take at least 24 hours with the storm's center over water for it to become a hurricane.

Impact of Isaac on the Islands
The south coast of Puerto Rico should see Isaac's heaviest rains and strongest winds beginning near 8 pm EDT tonight, with tropical storm-force winds of 40 - 45 mph potentially affecting the southwest portion of the island. The San Juan airport may be able to stay open during Isaac's passage, but with delays when spiral bands move overhead.

Heavy rains and tropical storm-force winds should arrive on the southern coast of the Dominican Republic late tonight, and the Santo Domingo airport will probably be closed on Friday. Rainfall amounts of 8 - 12 inches will likely affect the Dominican Republic Thursday through Saturday, creating dangerous flash floods and mudslides.

Isaac is potentially a very dangerous storm for Haiti, where 400,000 people still live outside underneath tarps in the wake of the 2010 earthquake. Heavy rains from Isaac will begin on Friday morning in Haiti, and last through Sunday. Rainfall amounts of 8 - 12 inches are possible, which will be capable of causing extreme flooding on the vegetation-denuded slopes of Haiti. It will be a major challenge to keep those Haitians living outside safe, if rainfall amounts of 5 - 10 inches occur.

Impact on Florida, Cuba, Jamaica, and the Bahamas
Florida, Cuba, Jamaica, and the Bahamas are all at risk of receiving flooding rains and high winds from Isaac. The latest set of 00Z (8 pm EDT) and 06Z (2 am EDT) model runs for Isaac are fairly unified for the coming three days, showing a west-northwestward track over Southwest Haiti and into Western Cuba. At the 4 - 5 day forecast period for Sunday and Monday, the models have come into better agreement, and have shifted west some. Our best-performing model, the ECMWF, has now shifted Isaac's path more to the east, but still is the westernmost of the models, predicting a landfall for Isaac near the Alabama/Florida border on Wednesday. While we do still have some models predicting a path up the east coast of Florida, model consensus now favors a path up the west coast of Florida through the Gulf of Mexico. The recent reformation of Isaac's center more to the south supports the idea that Isaac will take a track more to the west through the Gulf of Mexico. Since this now means a final landfall for Isaac in the Florida Panhandle is likely, the storm will probably have an extra day over water, increasing the odds that it will become a Category 2 or stronger hurricane before this final landfall. The NOAA jet is scheduled to fly into the storm this afternoon, to do a large-scale dropsonde mission to aid model forecasts. These missions can improve model forecasts by 10 - 20%, so the model runs that will be available early Friday morning should have increased reliability.

Impact on Tampa, Florida
The Republican National Convention begins on Monday in Tampa, Florida. The latest 11 am EDT wind probability forecast from NHC gives Tampa a 15% chance of receiving tropical storm-force winds and a 1% chance of receiving hurricane-force winds on Monday. The latest model tracks for Isaac suggests that the trough of low pressure pulling the storm to the north will not be strong enough to give Isaac a northeastward component of motion when it crosses Tampa's latitude. Thus, Isaac will have difficulty making a direct hit on Tampa without passing over a considerable amount of land first, making a multi-billion dollar hurricane disaster in Tampa very unlikely. I put the odds of a mass evacuation occurring during the convention at 1%; a limited evacuation of people in the Tampa Bay area living in mobile homes in low-lying areas is probably about 5 - 10 % likely. I have detailed information on Tampa's storm surge vulnerability in a post from last week.


Figure 2. Morning satellite image of Tropical Storm Joyce.

Tropical Storm Joyce forms in the Central Atlantic
The season's tenth named storm of the year, Tropical Storm Joyce, has formed in the Central Atlantic. Joyce's formation on August 23 puts 2012 in a tie for second place with 1995 for earliest formation date of the season's tenth storm. Only 2005 had an earlier appearance of the season's tenth storm, when Tropical Storm Jose formed at 2 pm EDT on August 22. None of the models show that Joyce will be a threat to the Lesser Antilles Islands, but it may be a storm that will affect Bermuda. It is possible that Joyce will complicate the track forecast for Isaac 4 - 5 days from now, when the storms may be close enough together to interact.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 874 - 824

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36Blog Index

No wind shift yet on recon... interesting. Also no sfc winds of even 40 mph yet. Other than that cat 3 wind reading ;)
Member Since: Posts: Comments:
A stream of dry air into Isaac from the NE...

Member Since: August 2, 2010 Posts: 21 Comments: 9807
872. wpb
Quoting GTcooliebai:
Euro 24 hrs. coming in stronger at 999 mb.

thanks for posting
Member Since: Posts: Comments:
000
ABNT20 KNHC 231755
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT THU AUG 23 2012

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM ISAAC...LOCATED ABOUT 165 MILES SOUTH OF SAN JUAN PUERTO
RICO...AND RECENTLY UPGRADED TROPICAL STORM JOYCE...LOCATED ABOUT
1305 MILES EAST OF THE LEEWARD ISLANDS.

SHOWER AND THUNDERSTORM ACTIVITY REMAINS MINIMAL IN ASSOCIATION
WITH A TROPICAL WAVE LOCATED BETWEEN THE WEST COAST OF AFRICA AND
THE CAPE VERDE ISLANDS. ANY DEVELOPMENT OF THIS DISTURBANCE IS
EXPECTED TO BE SLOW TO OCCUR...AND THIS SYSTEM HAS A LOW CHANCE...
10 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48
HOURS AS IT MOVES GENERALLY WESTWARD AT ABOUT 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BROWN


Member Since: October 3, 2010 Posts: 40 Comments: 4129
Quoting ProgressivePulse:
IT SHOULD BE NOTED...THOUGH...THAT NEAR THE 96
HR POINT THE GUIDANCE MODELS ARE SPREAD BETWEEN SOUTHEASTERN
FLORIDA AND WESTERN CUBA...AND AT 120 HR THEY ARE BETWEEN
NORTHEASTERN FLORIDA AND THE CENTRAL GULF OF MEXICO. THUS...
SIGNIFICANT UNCERTAINTY REMAINS ABOUT THE THREAT ISAAC POSES TO
FLORIDA.


If the NHC is uncertain about the track then no one should be calling anyone out on this blog yet about wrong forecasts..What a weekend this will be..
Member Since: Posts: Comments:
Quoting GTcooliebai:
Euro 24 hrs. coming in stronger at 999 mb.



.
Member Since: September 6, 2007 Posts: 0 Comments: 6373
Can someone tell me if Isaac is getting stronger and if it is moving to the northwest, i.e. closer to Puerto Rico? When I look at the floaters it seems like it, but my knowledge of this is fairly limited.TIA.
Member Since: Posts: Comments:
The G-IV is now airborne. Its data is going to be useful, but really, we're not going to have a great sense of Isaac until tomorrow morning. By then, we'll know if it's consolidating and organizing; we'll have vastly better environmental data; and the three-day cone (which is pretty much as far as we can meaningfully forecast, anyway) will give us a sense of landfall. In the interim, we're mostly just waiting.

The readings coming out of the Air Force C-130J on its first pass through the storm show a broad windfield, deepening pressure, and continued disorganization. It seems to be hunting vortices, and may be flying into a second one right now.

I'll confess to a degree of frustration. Clear answers are satisfying. But I'm also fascinated. The models tell us Isaac should strengthen. It's strikingly large for a tropical storm. It's been firing up some serious convection every d-min. And yet it's not behaving the way it's supposed to. And isn't that what makes this interesting?
Member Since: Posts: Comments:
Quoting GTcooliebai:
I expect the blog to go into meltdown mode now and say that's not where the center is.


LOL !
Member Since: Posts: Comments:
Quoting StormTracker2K:


If I had a dollar everytime I was critized eventhough I was right about a forecast.


You'd be broke? ;)
Member Since: September 6, 2007 Posts: 0 Comments: 6373
Center is around 15.8 N
Member Since: August 1, 2011 Posts: 28 Comments: 8007
Quoting VAbeachhurricanes:
Isaac is trolling us...
LOL he sure is
Member Since: August 6, 2011 Posts: 4 Comments: 38252
Just not strengthening... while the cloud pattern has improved, Isaac is still unable to fire convection right over the center... until he does that, he won't strengthen much.
Member Since: Posts: Comments:
Noaa9 is up now!!!
Member Since: Posts: Comments:
deleted
Member Since: Posts: Comments:
Recon seeming to indicate the center is NOT at 16N.
Member Since: Posts: Comments:
Quoting aislinnpaps:


Between Katrina and Rita, three weeks apart, both the coastlines of MS and LA were wiped out.
You are quite correct. There is still significant damage to the area. Many areas from 90 to the railroad tracks are still stripped clean(only the foundation remaining.)
Member Since: Posts: Comments:
Euro 24 hrs. coming in stronger at 999 mb.

Member Since: Posts: Comments:
Quoting floridaboy14:
wnw? sorry not buying it. its moving west on satalite.
it is not going to fight that ridge to the west for very long, it has to start a turn probably friday night into saturday..things are different than when ernesto was coming thru there, nothing was making him turn..this time there is
Member Since: August 6, 2011 Posts: 4 Comments: 38252
LinkGFSLoop

The Florida Keys should have a pretty good idea tomorrow morning when the new model runs come out about what to expect from Isaac. Today's GFS animation (above) shows Isaac pretty much over the Keys once it extracts from Cuba.
Also, here's the official track and intensity from the NHC for the next five days which shows a CAT 1 over the keys on Monday, but check back tomorrow after the new model runs and once Isaac has another day to develop.
Member Since: Posts: Comments:

000
WTNT34 KNHC 231753
TCPAT4

BULLETIN
TROPICAL STORM ISAAC INTERMEDIATE ADVISORY NUMBER 10A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
200 PM AST THU AUG 23 2012

...CENTER OF ISAAC NOW MOVING WEST-NORTHWESTWARD SOUTH OF PUERTO
RICO...


SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...16.0N 66.4W
ABOUT 165 MI...255 KM S OF SAN JUAN PUERTO RICO
ABOUT 275 MI...445 KM SE OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


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

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* SOUTH COAST OF DOMINICAN REPUBLIC FROM ISLA SAONA WESTWARD TO THE
HAITI-DOMINICAN REPUBLIC SOUTHERN BORDER
* HAITI

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* BRITISH VIRGIN ISLANDS
* PUERTO RICO...VIEQUES...CULEBRA...AND THE U.S. VIRGIN ISLANDS
* NORTH COAST OF DOMINICAN REPUBLIC FROM THE HAITI-DOMINICAN
REPUBLIC NORTHERN BORDER EASTWARD TO NORTH OF ISLA SAONA

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* SOUTHEASTERN BAHAMAS INCLUDING THE ACKLINS...CROOKED
ISLAND...LONG CAY...THE INAGUAS...MAYAGUANA...AND THE RAGGED
ISLANDS AND THE TURKS AND CAICOS ISLANDS

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

INTERESTS IN CUBA...JAMAICA...AND ELSEWHERE IN THE BAHAMAS SHOULD
MONITOR THE PROGRESS OF ISAAC.

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 200 PM AST...1800 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 16.0 NORTH...LONGITUDE 66.4 WEST. ISAAC IS NOW
MOVING TOWARD THE WEST-NORTHWEST NEAR 15 MPH...24 KM/H...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE THROUGH SATURDAY. ON THE
FORECAST TRACK...THE CENTER OF ISAAC WILL CONTINUE TO PASS SOUTH OF
PUERTO RICO TODAY...AND BE NEAR THE SOUTH COAST OF THE DOMINICAN
REPUBLIC AND HAITI ON FRIDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/H...WITH HIGHER
GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND
ISAAC COULD BECOME A HURRICANE AS IT NEARS THE DOMINICAN REPUBLIC
AND HAITI. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS
CURRENTLY INVESTIGATING ISAAC.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140 MILES...220 KM
FROM THE CENTER. NOAA BUOY 42060 RECENTLY REPORTED 1-MINUTE MEAN
WINDS OF 40 MPH...65 KM/HR...AND A WIND GUST OF 47 MPH...76 KM/HR.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB...29.62 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE SUBSIDING OVER THE LEEWARD
ISLANDS. TROPICAL STORM CONDITIONS ARE EXPECTED OVER PORTIONS OF
PUERTO RICO AND THE U.S. AND BRITISH VIRGIN ISLANDS THIS AFTERNOON.
HURRICANE CONDITIONS ARE EXPECTED OVER PORTIONS OF THE DOMINICAN
REPUBLIC BY FRIDAY...AND OVER PORTIONS OF HAITI FRIDAY OR FRIDAY
NIGHT. TROPICAL STORM CONDITIONS ARE POSSIBLE OVER THE
SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS BY LATE
FRIDAY.

RAINFALL...TOTAL RAINFALL ACCUMULATIONS OF 8 TO 12 INCHES...
WITH MAXIMUM AMOUNTS OF 20 INCHES...ARE POSSIBLE OVER HISPANIOLA.
THESE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD
SLIDES. TOTAL RAIN ACCUMULATIONS OF 2 TO 4 INCHES...WITH MAXIMUM
AMOUNTS OF 10 INCHES OVER HIGHER TERRAIN...ARE POSSIBLE OVER PUERTO
RICO AND THE VIRGIN ISLANDS. TOTAL RAIN ACCUMULATIONS OF 4 TO 8
INCHES ARE POSSIBLE OVER THE NORTHERN WINDWARD ISLANDS AND THE
LEEWARD ISLANDS.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS
3 TO 5 FEET ABOVE NORMAL TIDE LEVELS IN AREAS OF ONSHORE WINDS ALONG
THE COAST OF HISPANIOLA. A STORM SURGE WILL RAISE WATER LEVELS BY
AS MUCH AS 1 TO 3 FEET ABOVE NORMAL TIDE LEVELS IN THE NORTHERN
LEEWARD ISLANDS...PUERTO RICO...AND THE U.S. AND BRITISH VIRGIN
ISLANDS. NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY
DANGEROUS WAVES.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT THE
WINDWARD ISLANDS...LEEWARD ISLANDS...VIRGIN ISLANDS...AND PUERTO
RICO DURING THE NEXT COUPLE OF DAYS. PLEASE CONSULT PRODUCTS FROM
YOUR LOCAL WEATHER OFFICE FOR MORE INFORMATION.


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

$$
FORECASTER BEVEN
Member Since: Posts: Comments:
Quoting StormTracker2K:


If I had a dollar everytime I was critized eventhough I was right about a forecast.


you would have 1 dollar? lol

j/k, you are one of the good ones on here
Member Since: Posts: Comments:
1004 mb so far at the center... there was a 1002 mb mark though in north side of Isaac, but not a true center.
Member Since: August 1, 2011 Posts: 28 Comments: 8007
Isaac is trolling us...
Member Since: September 6, 2007 Posts: 0 Comments: 6373
Well, the WNW turn that Isaac was predicted to take if it was to traverse Haiti, is now a NW turn.
Member Since: Posts: Comments:
Quoting GTcooliebai:
I expect the blog to go into meltdown mode now and say that's not where the center is.


LOL!! of course
Member Since: Posts: Comments:
Quoting Levi32:
Will be very interesting to see exactly how far north the center is:




Or better yet how far south!!! LOL
Member Since: July 4, 2005 Posts: 204 Comments: 8858
847. Relix
WNW...

Feels so good to win that debate :p
Member Since: Posts: Comments:

000
WTNT44 KNHC 231453
TCDAT4

TROPICAL STORM ISAAC DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1100 AM AST THU AUG 23 2012

THE SATELLITE APPEARANCE OF ISAAC HAS IMPROVED SOMEWHAT THIS
MORNING...WITH MULTIPLE CONVECTIVE BANDS DEVELOPING AROUND THE
CENTER. HOWEVER...REPORTS FROM AIR FORCE RESERVE AND NOAA
HURRICANE HUNTER AIRCRAFT INDICATE THAT THE CENTRAL CORE OF ISAAC
REMAINS POORLY ORGANIZED...WITH MULTIPLE LOW-LEVEL VORTICITY CENTERS
ROTATING AROUND A LARGE AREA OF LIGHT WINDS. IN ADDITION...THE
CENTER IN AIRCRAFT DATA IS NORTH OF THE CENTER SUGGESTED BY THE
SATELLITE IMAGERY. A COMBINATION OF FLIGHT-LEVEL...DROPSONDE...AND
SFMR WINDS SUGGEST THAT THE INITIAL INTENSITY IS NEAR 35 KT.

THE OVERALL CIRCULATION OF ISAAC IS A LITTLE FARTHER SOUTH THAN 12
HR AGO. HOWEVER...IT SEEMS TO HAVE RESUMED A WESTWARD MOTION AT
ABOUT 13 KT. THE TRACK MODEL GUIDANCE IS IN GOOD AGREEMENT THAT
ISAAC SHOULD MOVE WEST-NORTHWESTWARD FOR THE NEXT 36-48 HR...
STEERED BY THE SUBTROPICAL RIDGE TO THE NORTH. AFTER THAT...THE
STORM SHOULD APPROACH A WEAKNESS OR BREAK IN THE RIDGE OVER FLORIDA
AND THE EASTERN GULF OF MEXICO. THE NEW FORECAST TRACK IS SHIFTED A
LITTLE TO THE WEST OF THE PREVIOUS TRACK BASED ON CURRENT POSITION
AND LIES DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE NEAR THE
CONSENSUS MODELS. IT SHOULD BE NOTED...THOUGH...THAT NEAR THE 96
HR POINT THE GUIDANCE MODELS ARE SPREAD BETWEEN SOUTHEASTERN
FLORIDA AND WESTERN CUBA...AND AT 120 HR THEY ARE BETWEEN
NORTHEASTERN FLORIDA AND THE CENTRAL GULF OF MEXICO. THUS...
SIGNIFICANT UNCERTAINTY REMAINS ABOUT THE THREAT ISAAC POSES TO
FLORIDA.

IN THE SHORT TERM...THE STRUCTURE OF ISAAC SUGGESTS THAT ONLY SLOW
STRENGTHENING IS LIKELY. HOWEVER...THE ENVIRONMENTAL CONDITIONS
ARE FAVORABLE FOR RAPID INTENSIFICATION...WHICH COULD OCCUR IF THE
CYCLONE DEVELOPS A WELL-DEFINED INNER CORE. BASED ON THIS...THE
INTENSITY FORECAST CONTINUES TO SHOW HURRICANE STRENGTH BEFORE THE
SYSTEM REACHES HISPANIOLA IN ABOUT 36 HR. AFTER THAT...PASSAGE OVER
HISPANIOLA AND CUBA SHOULD CAUSE SOME WEAKENING...FOLLOWED BY
LITTLE CHANGE OF STRENGTH FROM 48-72 HR. THE INTENSITY FORECAST
SHOWS A LITTLE MORE STRENGTHENING OVER THE GULF OF MEXICO DUE TO
THE FORECAST TRACK BEING A LITTLE FARTHER FROM THE FLORIDA
PENINSULA THAN BEFORE. THE INTENSITY FORECAST IS BASED ON A BLEND
OF THE PREVIOUS FORECAST AND THE SHIPS/LGEM MODELS...AND IT IS WELL
ABOVE THE INTENSITY CONSENSUS.


FORECAST POSITIONS AND MAX WINDS

INIT 23/1500Z 15.6N 65.4W 35 KT 40 MPH
12H 24/0000Z 16.1N 67.4W 40 KT 45 MPH
24H 24/1200Z 16.9N 70.0W 50 KT 60 MPH
36H 25/0000Z 18.0N 72.4W 65 KT 75 MPH
48H 25/1200Z 19.3N 74.6W 55 KT 65 MPH
72H 26/1200Z 22.0N 78.5W 55 KT 65 MPH...INLAND
96H 27/1200Z 24.5N 81.5W 65 KT 75 MPH...OVER WATER
120H 28/1200Z 27.5N 84.5W 75 KT 85 MPH

$$
FORECASTER BEVEN
Member Since: Posts: Comments:
Quoting Relix:
Really? Attacking Levi? That's the kind of stuff that has scared away several great members. Just because you want something to happen doesn't mean you need to attack others. I trust Levi more than 99% of some of the idiots who post here, and I could start naming some but I'll hold off. The guy knows, and he knows more than many of you. Can he be wrong? Absolutely, same as NHC. \

Yes, you want the storm to hit you. No, nothing ever goes according to plan.


I live a whole 5 feet from the Gulf of Mexico--0- Dauphin ISLAND, AL. I have two small children 3 and 5 months... Why would I want a storm to hit me hot shot??? Get your head above your sholders
Member Since: Posts: Comments:
Quoting Levi32:
Will be very interesting to see exactly how far north the center is:



Still at 15
Member Since: Posts: Comments:
Quoting Bluestorm5:
This makes me excited for the future of hurricane tracking...




what website is that i would love to see it too!!
Member Since: Posts: Comments:
Quoting drg0dOwnCountry:
Tourists allowed to stay in Florida Keys for now

Link


Kinda quiet down here this time of year anyway.
Member Since: Posts: Comments:
Quoting trey33:


That would be terrible for Tampa
yes it would trey..we are in for an awful beginning of next week,wind, rain and stormy weather, local mets put the chance at 70%..monday morning it could be 100%
Member Since: August 6, 2011 Posts: 4 Comments: 38252
wnw? sorry not buying it. its moving west on satalite.
Member Since: Posts: Comments:
Quoting VAbeachhurricanes:
My god, Levi's a big boy he can defend himself we don't need this every freaking day here on the blog. Someone criticizing his forecast is not criticizing him as a person.


If I had a dollar everytime I was critized eventhough I was right about a forecast.
Member Since: October 26, 2011 Posts: 0 Comments: 2651
Quoting WDEmobmet:


Understand the situation now regarding your forecast prior to the 12z... And again I am only trying to help please dont take it negatively but my concern is that if you choose to take a path in lets says industrial met. you have to give various options to forecast. I recall you saying that no matter how you slice it it is going to be a florida storm, but in the same sentence you say that there is a lot that can change in 4-5 days. I agree with alerting people but you say that you are alerting them of possible scenarios, however I have seen no mention of a track west of florida which is been a possibility for at least 2 days. So in reality your ultimately denying the possibility of any other track. I have noticed that your cone does stretch on the western side, but becuase alot of people do depend on your forecast and do treat it as gospel they may not get the full pie only a piece. You may ultimately let them down


I spend many breaths in each video stressing the amount of uncertainty in a 4-5 day forecast and the different possibilities that are on the table besides my exact track. If some people don't know how to listen, that's not really my problem.
Member Since: November 24, 2005 Posts: 635 Comments: 26614
WNW now!!!
Member Since: Posts: Comments:
What is the link to the HH on Google Earth
Member Since: Posts: Comments:
Isaac is not IN the east Caribbean, it IS the east Caribbean.
Member Since: Posts: Comments:
Quoting hurricanehanna:
2:00 PM AST Thu Aug 23
Location: 16.0°N 66.4°W
Moving: WNW at 15 mph
Min pressure: 1003 mb
Max sustained: 40 mph
I expect the blog to go into meltdown mode now and say that's not where the center is.
Member Since: Posts: Comments:
IT SHOULD BE NOTED...THOUGH...THAT NEAR THE 96
HR POINT THE GUIDANCE MODELS ARE SPREAD BETWEEN SOUTHEASTERN
FLORIDA AND WESTERN CUBA...AND AT 120 HR THEY ARE BETWEEN
NORTHEASTERN FLORIDA AND THE CENTRAL GULF OF MEXICO. THUS...
SIGNIFICANT UNCERTAINTY REMAINS ABOUT THE THREAT ISAAC POSES TO
FLORIDA.
Member Since: Posts: Comments:
Quoting WDEmobmet:


Understand the situation now regarding your forecast prior to the 12z... And again I am only trying to help please dont take it negatively but my concern is that if you choose to take a path in lets says industrial met. you have to give various options to forecast. I recall you saying that no matter how you slice it it is going to be a florida storm, but in the same sentence you say that there is a lot that can change in 4-5 days. I agree with alerting people but you say that you are alerting them of possible scenarios, however I have seen no mention of a track west of florida which is been a possibility for at least 2 days. So in reality your ultimately denying the possibility of any other track. I have noticed that your cone does stretch on the western side, but becuase alot of people do depend on your forecast and do treat it as gospel they may not get the full pie only a piece. You may ultimately let them down


Basically what I'm reading in your post is that you feel Levi should agree with what the general mets say, or TWC. Levi is a very competant forecaster and is posting 'his' thoughts of the path. Anyone here, and many do, post their thoughts on paths. I really don't think anyone will take what one person says as gospel.
Member Since: August 22, 2009 Posts: 0 Comments: 3115
Quoting Levi32:
Will be very interesting to see exactly how far north the center is:



Yes, it will. Not surprising to find it still 15n, maybe 14.8n - all further south than the official forecast this morning. And, fairly far away from being able to feel the tug of the departing weakness.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
830. MTWX
Quoting moonlightcowboy:


Yeah, we're used to it. LA got all the press. MS was splintered from the beach all the way to Pickwick Lake where it exited the state.


We still had wind gusts over 100 mph here in Columbus with sustained at 70 MPH!! And that is ~250 miles inland!! (I moved up here from Biloxi only 4 months prior to the storm)
Member Since: Posts: Comments:
when does the 12z ECMWF model come out?
Member Since: Posts: Comments:
Tropical Storm ISAAC
...CENTER OF ISAAC NOW MOVING WEST-NORTHWESTWARD SOUTH OF PUERTO RICO...
2:00 PM AST Thu Aug 23
Location: 16.0°N 66.4°W
Moving: WNW at 15 mph
Min pressure: 1003 mb
Max sustained: 40 mph
Member Since: Posts: Comments:
When does the new Euro come out?
Member Since: Posts: Comments:
Quoting NovaScotia33:
Hi guys. Long time lurker from Halifac NS on the east coast of Canada. The mets up here have started discussing a possibility of an eventual tag team hit between Joyce and Isaac depending on timing. What are your thoughts? Thanks guys. I love the knowledge I get from this site. Cheers.


Umm, I am from there too and I'd like to know who you are referring too... there is no model support for that.
Member Since: Posts: Comments:
Location: 16.0°N 66.4°W
Moving: WNW at 15 mph
Min pressure: 1003 mb
Max sustained: 40 mph
Member Since: August 6, 2007 Posts: 0 Comments: 693
2:00 PM AST Thu Aug 23
Location: 16.0°N 66.4°W
Moving: WNW at 15 mph
Min pressure: 1003 mb
Max sustained: 40 mph
Member Since: Posts: Comments:

Viewing: 874 - 824

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.