Tropical Tidbits from the Tundra

First tropical depression of the south Pacific season

By: Levi32, 12:08 AM GMT on November 27, 2010

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South Pacific and Coral Sea Visible/IR Satellite:



South Pacific Surface Analysis:



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





Updated: 9:54 PM GMT on February 08, 2011

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"Epoch" rain event for interior Alaska, as well as a potent ice threat

By: Levi32, 5:18 PM GMT on November 22, 2010

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MIDDLE TANANA VALLEY-
INCLUDING...FAIRBANKS...FORT WAINWRIGHT...EIELSON AFB...ESTER...
NORTH POLE...MOOSE CREEK...TWO RIVERS...FOX...CHATANIKA...
CHENA HOT SPRINGS...SOURDOUGH CAMP
606 AM AKST MON NOV 22 2010

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM AKST
TUESDAY FOR FREEZING RAIN...

A WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM AKST TUESDAY.

AN EXTREMELY WARM AND MOIST AIR MASS...MOVING AROUND A LARGE HIGH
PRESSURE SYSTEM OVER THE NORTH PACIFIC...WILL BRING PERIODS OF
RAIN THROUGH TUESDAY. EVEN THOUGH TEMPERATURES WILL BE SLIGHTLY
ABOVE FREEZING IN MANY AREAS...RAIN WILL RAPIDLY FREEZE ON
EXPOSED SURFACES. DRIVING CONDITIONS WILL BECOME EXTREMELY
DANGEROUS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING MEANS SIGNIFICANT WINTER WEATHER HAZARDS
ARE EXPECTED. THIS WILL MAKE TRAVEL AND OUTDOOR ACTIVITY VERY
HAZARDOUS.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
630 AM AKST MON NOV 22 2010

AKZ101-111-145-11230000-

...SIGNIFICANT ICE ACCUMULATION AROUND SOUTHCENTRAL ALASKA...

WIDESPREAD FREEZING RAIN IS FALLING AROUND SOUTHCENTRAL ALASKA THIS
MORNING. TEMPERATURES AT THE SURFACE REMAIN BELOW FREEZING WHILE
TEMPERATURES ALOFT REMAIN MUCH WARMER. RAIN THAT IS FALLING IS
FREEZING ON CONTACT AND CAUSING HAZARDOUS DRIVING CONDITIONS.

PRECIPITATION WILL TAPER OFF FROM THE SOUTH THIS MORNING IN ANCHORAGE
AND LATER THIS AFTERNOON ACROSS THE MATANUSKA VALLEY. THE SUSITNA
VALLEY WILL SEE A MUCH LONGER SUSTAINED PERIOD OF PRECIPITATION
THROUGH TUESDAY.

TEMPERATURES WILL GRADUALLY WARM LATER TONIGHT AS THE NEXT BATCH OF
MOISTURE ARRIVES ACROSS SOUTHCENTRAL ALASKA. THE POTENTIAL FOR
ANOTHER SIGNIFICANT FREEZING RAIN EVENT IS POSSIBLE AGAIN TONIGHT
THROUGH TUESDAY MORNING.



Fairbanks, AK Radar Loop:



Alaska IR Satellite (click for loop):



Alaska Warnings and Advisories (click on map for specific zones):



Alaska Surface Analysis:



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






Updated: 5:23 PM GMT on November 22, 2010

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A glance at the 2010-2011 winter for North America, including Alaska

By: Levi32, 5:36 PM GMT on November 18, 2010

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The video today touches on the winter forecast for North America, giving emphasis to Alaska which gets ignored a lot :)

This is a "torpid" tidbit instead of a tropical tidbit. Most of the Atlantic tropical things have been removed from the blog now that we are shutting down the Atlantic for the winter, but southern hemisphere tropical events, especially the ones threatening land such as Australia, will likely get covered if they are significant.

We shall see what happens!


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






Updated: 5:37 PM GMT on November 18, 2010

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Atlantic Hurricane Season 2010 pretty much over; Tropical focus shifts elsewhere

By: Levi32, 5:48 PM GMT on November 17, 2010

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The Atlantic Hurricane Season of 2010 is pretty much over now, with the official end only a couple weeks away. We had an area to watch in the western Caribbean but conditions are too dry right now to allow development. Upward motion will be returning to the central Atlantic and eastern Caribbean over the next couple of weeks, but at this point any further developments are more unlikely than likely.

My forecast for this year of 18 named storms verified pretty well, as we ended with 19. What did not turn out was the forecasted impact on the United States, which ended up lower than almost every forecast out there. We had the congregation of tracks on either side of where the focus seemed most likely to be, and it is a statistical miracle that the U.S. saw so little impact in a season this active. The main areas that got slammed were Bermuda and Central America, which definitely had the worst of this season.

In terms of the tropics, our focus will now have to shift down to the southern hemisphere during their summer season. Looking at SSTs around the globe, the main focus of heat available for redistribution via tropical cyclones is now being found in the vicinity of Australia and south of the Maritime Continent. The ECMWF forecast for January-February-March follows the logical approach and shows very low sea-level pressures and high precipitation around Australia during their tropical season, and although the south Pacific and Indian Ocean seasons are not typically that active compared to the rest of the ocean basins, Australia may have to watch for tropical impacts this year.

We also have a lot of winter to look forward to here in the northern hemisphere, and I may touch on that a few times as things unfold up here.

On another note, for any who are interested in reading it, I am posting a pdf of my first research paper that I have written for my English class here at UAF. My teacher allowed me to pursue whatever subject I desired, and so naturally I chose Meteorology. I have a great English teacher, but unfortunately she's not a Meteorologist, and thus I am afraid cannot give me a complete and brutally honest review of my paper from a content standpoint. I thought it would help me to submit it to any of you weather geeks like me here at WU who would like to read it and share their thoughts on how I could improve it, sort of like peer-review I guess. Being my first-ever research paper, it is sure to have flaws regarding typical Meteorology papers that my English teacher is likely to miss. I would appreciate any advice and feedback on how I could make my research papers better, as it is a skill I certainly need to have.

Here is the link:

The Effects of Meridional Sea Surface Temperature Gradients on the Atlantic Hurricane Season

We shall see what happens!


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):






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Hurricane Tomas a big flooding threat to Haiti; Hurricane Season still not over?

By: Levi32, 4:27 PM GMT on November 05, 2010

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Hurricane Tomas is now moving up between Jamaica, Cuba, and Haiti with 85mph winds and will continue on out to the NNE today through the SE Bahamas. The center is taking one of the better paths for wind impacts as it is a mostly water path, with the center only clipping perhaps eastern Cuba with no really solid landfalls as it passes through. However, Tomas is taking a very bad path for rainfall across Haiti, which can be disastrous when tropical cyclones run through.

Tomas' core is a bit ragged this morning despite decent deepening last night, likely due to interaction with the high mountains of Haiti and Cuba. Tomas didn't get up to Cat 2 before affecting the big Caribbean islands, and although he will likely be trying to get up to that intensity as he gets further north, that is still later than I thought, so the intensity forecast turned out to be a bit low here. However, one can see how the idea that this would develop, turn north, and the fact that it would come back from the dead and become a hurricane again, all panned out as planned. Hopefully folks in Hispaniola, Cuba, Jamaica, and the Bahamas were all prepared for this despite the naked swirl that we saw just a couple days ago.

Tomas may not be the last storm we have to deal with either before this season is finally over. The GFS upward motion forecast currently calls for extreme amounts of rising air over the tropical Atlantic in two weeks, and this makes at least some sense given the troughing autumn pattern that will be continuing over the eastern United States. The TUTT has also been busy in the central and eastern Atlantic, meaning that if we get another development it will likely be another situation similar to Tomas, where mischief starts in the eastern Atlantic, but then gets handed off to the other area of upward motion to the west in the Caribbean, where it would then get named and cause problems.

The video also shows the incredible pattern currently underway with a northwest flow out of Canada all the way down to Panama and the ITCZ, making it look like a degraded cold front has come all the way down and merged with the ITCZ, taking a flow out of the deep tropics northward with a hurricane embedded within. This is the ultimate way to take heat out of the tropics and funnel it into the mid-latitudes. The lengths that the atmosphere is going to here to get energy out of the Caribbean is just amazing.

We shall see what happens!

Hurricane Tomas Visible/IR2 Satellite (click image for loop):



Hurricane Tomas Track 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):






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Tomas reorganizing: still a significant threat to Haiti, Jamaica, Cuba, and Bahamas

By: Levi32, 4:01 PM GMT on November 03, 2010

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Tomas has finally been downgraded to a tropical depression, which is what it has been for the past 24 hours based on obvious recon data. This implies weakening but the system has in fact gotten better organized since yesterday, and it will be interesting to see what the next plane finds when they investigate Tomas later today.

What is most interesting is the NHC 11am position near 14N, 76W which is where the recon barely found a center last night, and is right where satellite vorticity estimates have a strong maximum. I don't believe this center position, as if you look closely at visible loops of the area, there is a clear spot there allowing us to see the low-level clouds, and I see nothing but westerly winds in the vicinity. To me the center looks to have reformed off to the northeast closer to the main area of convection, and the spin looks to be becoming more defined there at both low and mid-levels. It will be interesting to see where the recon finds the center later today.

Overall the forecast ideas here remain the same. Given the excellent pattern that Tomas is in for strengthening, we should see him back to tropical storm strength sometime today, and likely making a run at hurricane intensity sometime tomorrow. The reason this makes sense is that as Tomas makes progress westward, he's coming closer and closer to the area of maximum favorability for strengthening of a tropical cyclone, which is the intersection point between the converging trade winds and upper divergence from the trough diving into Texas.

The area of persistent convection south and southwest of Jamaica has been just an amazing tool. If you didn't believe me that this was indicating where the periphery of the high was going to set up, just look directly north towards the southeast U.S. and notice where the surface winds curve from easterly to SSE. If you draw a line southward it will run right over Jamaica and through that area of convection that has been there for 3 days now. This has been indicating the favorable area for tropical development forever now, and it's a splendid example of how to use the surrounding environment to make predictions on track and intensity. Here it has been marking where Tomas will start turning north and also where he will begin strengthening again. So far, this theory looks to be right on par, but we still have a ways to go in the forecast.

For intensity, I still feel that Cat 2 at landfall in the vicinity of Haiti or eastern Cuba is still the most likely scenario, with a major hurricane still a possibility with rapid feedback as this comes ashore. The NHC is getting nervous now due to Tomas' reluctance to come back to life, and is now only forecasting a minimal Cat 1 at landfall, which they say may be generous. I would beg to differ, as looking at latest satellite imagery, Tomas looks ready to roar again, and the recon should find an organizing storm when they go in later today. Rapid feedback in this very favorable pattern is very possible in the face of the advancing trough, and Haiti, Jamaica, and Cuba should be ready for impacts of a formidable hurricane of Cat 2 strength or higher.

Even if the forecast intensity here busts, the potential rainfall from this fairly slow-moving system as it recurves would still be a disaster for Haiti, because as we all know you don't even need the wind elements of a tropical storm to cause havoc in that country. This is why even if the intensity here ends up being overhyped, folks down there should be prepared for a very serious storm. And the fact remains that the potential for rapid intensification of this system as it moves northward is there, and that's why, despite how weak Tomas has been over the last few days, folks should continue to keep a very close eye on him, as by the time Friday comes around, they could be staring down something much more vicious.

We shall see what happens!

Tropical Storm Tomas Visible/IR2 Satellite (click image for loop):



Tropical Storm Tomas Track 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: 4:01 PM GMT on November 03, 2010

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Tomas to threaten Jamaica, Haiti, and Cuba as at least a Cat 2, possibly a major

By: Levi32, 4:26 PM GMT on November 02, 2010

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 or questions about the video.



Tomas is making his comeback now north of Columbia as convection is firing like crazy near the center, and pressures are likely lowering healthily in the area right now. As I type the recon is flying in and will see how Tomas is doing. One can see how the area of convection south of Jamaica has has been an amazing forecast helper for the last couple days, as it has perpetually indicated the boundary where the fast trade wind flow has been converging, and thus indicating how Tomas was going to make a roaring comeback. As Tomas has come farther west the flow has become progressively more convergent in the path of the storm as opposed to divergent, which is what killed it with sinking air a couple days ago. Now the storm is roaring back to life and this will be a hurricane again by Thursday morning.

The convection south of Jamaica is also indicating to us where the periphery of the high is setting up and exactly where Tomas is going to go. From this we can surmise that Tomas will continue to travel west or WNW until he is at Jamaica's longitude, and then slow down and make an abrupt turn to the NNE or NE, perhaps clipping or hitting eastern Jamaica and then threatening eastern Cuba, Haiti, and the SE Bahamas. The current NHC forecast and model consensus has a direct hit on Haiti, which would be disastrous, but there is some wiggle room for adjustments farther west. These will be worked out with time, but the small triangular region bounded by extreme eastern Cuba, Jamaica, and Haiti is definitely going to see this storm blast through.

Rapid feedback as Tomas nears landfall could be a really big problem, as the pattern will be evolving over the next couple of days to favor massive pressure falls in the Caribbean as Tomas gets pulled northward and the jetstream becomes strongly kinked. The intensification of this storm as it comes ashore could truly be impressive and very scary. A Cat 2 hurricane is likely, and a major hurricane is very much on the table here if things fall into place. As I have said the past couple days, just because Tomas fell apart into a naked swirl doesn't mean folks should let their guard down in the northern Caribbean. This storm is a very big deal, and hopefully residents of Jamaica, Haiti, Cuba, and the Bahamas are prepared for a strong hurricane coming ashore on Friday.

We shall see what happens!

Tropical Storm Tomas Visible/IR2 Satellite (click image for loop):



Tropical Storm Tomas Track 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):






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Tomas to come back as a hurricane and threaten Jamaica, eastern Cuba, and Haiti

By: Levi32, 4:39 PM GMT on November 01, 2010

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 or questions about the video.



Tomas has weakened to a tropical storm as convection was stripped away from his center yesterday by sinking air on the western side of the storm due to racing trade winds out of the east to the west of the center. However, the area of convection south of Jamaica shows where the trade winds are slowing down and piling up, and this means that Tomas is going to come back and be a hurricane threatening the eastern Cuba, Jamaica, and Haiti area later this week. How strong this gets will depend on how fast it builds a new core. One can already see the hot-towers going off on the east side of the center as convection tries to rebuild. This could easily go back up to Cat 2 before landfall, and although chances of a major hurricane are lower since Tomas weakened a bit more than anticipated, we will have to keep an eye out for rapid feedback as this comes north into the trough.

The area of convergence in the western Caribbean south of Jamaica also illustrates where the periphery of the high is going to set up as the trough dives into the eastern US, and this is where Tomas will begin his turn to the north in 2-3 days. Depending on how strong he is, he may take his time getting dragged out of the Caribbean, which could cause a lot of problems if he's a slow mover, but if he becomes strong he will likely exit at a decent speed. Overall, the big Caribbean islands, specifically eastern Cuba, Jamaica, and Haiti, should be bracing for a hurricane later this week, possibly a strong one, despite the way the storm looks right now. The overall pattern spoken about for a while now dictates a favorable environment for a strong storm to develop in this area this week, so folks can't let their guard down.

We'll have to see if Tomas is the closing finale of the season. There is a suspicious-looking area east of the Caribbean within the ITCZ, and the MJO forecast shows upward motion remaining over the Atlantic and Caribbean through Day 15.

We shall see what happens!

Tropical Storm Tomas Visible/IR2 Satellite (click image for loop):



Tropical Storm Tomas Track 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):






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About Levi32

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

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NERRS NERRS METEOROLOGICAL SITE AT KAC AK US
Fritz Creek, AK
Elevation: 32 ft
Temperature: 51.0 °F
Dew Point: 51.0 °F
Humidity: 98%
Wind: 4.0 mph from the NE
Wind Gust: 6.0 mph
Updated: 7:30 AM AKDT on July 31, 2014
Overlooking Peterson Bay
Homer, AK
Elevation: 27 ft
Temperature: 49.4 °F
Dew Point: 26.7 °F
Humidity: 41%
Wind: Calm
Wind Gust: 0.0 mph
Updated: 8:08 AM AKDT on July 31, 2014
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Homer, AK
Elevation: 854 ft
Temperature: 60.0 °F
Dew Point: 53.0 °F
Humidity: 78%
Wind: 1.0 mph from the ESE
Wind Gust: 4.0 mph
Updated: 7:54 AM AKDT on July 31, 2014

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