Strengthening Tomas headed for the Lesser Antilles

By: Dr. Jeff Masters , 1:27 AM GMT on October 30, 2010

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Tropical Storm Tomas has exploded into existence in spectacular fashion, becoming the nineteenth named storm of this amazingly active 2010 Atlantic hurricane season. I'm reporting to you live from the National Hurricane Center tonight, where forecasters are working hard to stay abreast of Tomas' intensification. Three hurricane specialists are on duty tonight--Dave Roberts, who is handling Tropical Storm Shary, and Robbie Berg and Dan Brown, who are focusing on Tomas. The Hurricane Hunters have just left Tomas, as of 8pm EDT, and they found a significant increase in winds. Winds at their 1500 foot flight level were 70 mph, and surface winds as measured by the SFMR instrument were near 60 mph. This supports an increase in Tomas' winds to 60 mph in tonight's 8pm EDT public advisory. Since this is such a large increase in intensity from what was forecast--Tomas was not supposed to have 60 mph winds for another 24 hours--this necessitates issuance of a special advisory package. A full set of forecast maps, a marine advisory, wind probability forecast, and a discussion just went out to the world. While all this was occurring, several phone calls to Barbados, St. Lucia, and Martinique were made, alerting the islands to the fact that a Hurricane Warning may be required with the 11pm advisory tonight. NHC has both French speaking and Spanish speaking meteorologists on staff that can coordinate with the islands that don't have English as their main language. I listened in on a 5-minute conversation in French between the weather service in Martinique and NHC meteorologist Mike Tichacek, as they discussed when Martinique may want to issue a Hurricane Warning.


Figure 1. Warren VonWerne (right) of CARCAH presents the latest data from the Air Force Hurricane Hunters to hurricane specialist Robbie Berg.

Intensity forecast for Tomas
The forecasters at NHC are puzzling over the latest intensity forecasts for Tomas. The latest intensity forecast from the GFDL, HWRF, and SHIPS models are not that impressive, and they keep Tomas as a strong tropical storm or weak hurricane for the next five days. The wind shear forecast from SHIPS is particularly odd--the latest 18Z forecast predicts high wind shear of 20+ knots beginning Sunday morning, and the previous SHIPS forecast held wind shear below 15 knots for the next five days. The latest runs by the GFS, ECMWF, and UKMET models all show a very favorable environment for intensification over the next five days over the Caribbean, with Tomas positioning itself beneath an upper level high in a light wind shear environment. The best bet is that Tomas will intensify into a major hurricane over the Central Caribbean by early next week.


Figure 2. NHC meteorologist Mike Tichacek discusses the latest intensity forecast for Tomas with the Martinique weather service (in French.) In the background, hurricane specialist Dave Roberts works on advisories for Tropical Storm Shary.

Track forecast for Tomas
After Tomas reaches the central Caribbean 4 - 6 days from now, there are two possible track scenarios depicted by the models--a continued westerly motion towards Nicaragua, or a sharp turn to the north, with a track over Hispaniola or Puerto Rico. Steering currents will be weak, and we'll just have to wait and see how the steering currents evolve.

Tomas' formation location unprecedented this late in the season
Tomas' formation ties 2010 with 1995 and 1887 for 3rd place for most number of named storms in an Atlantic hurricane season. Only 2005 (28 named storms) and 1933 (21 named storms) were busier. Atlantic hurricane records go back to 1851, though there were likely many missed named storms prior to the beginning of satellite coverage in the mid-1960s.

The formation of a tropical storm so far south and east this late in the season is unprecedented in the historical record; no named storm has ever been present east of the Lesser Antilles (60°W) and south of 12°N latitude so late in the year. Hurricane Six of 1896 came close--it was also a tropical storm south of 12°N and east of 60°W on October 29, but nine hours earlier in the day. That storm recurved to the north and missed the Lesser Antilles. Tomas' track through the southern Lesser Antilles so late in the year is unprecedented. There have been only two other tropical storms that formed after October 15 south of 12°N and east of 60°W: Hurricane Jose, which was a tropical storm in that region on October 18, 1999, and Tropical Storm Nicolas, on October 16, 2003. Tomas most reminds me of Hurricane Joan of 1988, which was a tropical storm on October 14 near Tomas' current location, and later strengthened into a Category 4 hurricane that hit Nicaragua.

Another unusual aspect of Tomas' formation is that we now have two simultaneous named storms in the Atlantic Ocean on October 29. There have been only four hurricane seasons since 1851 that have had two simultaneous named storms later in the year. The record was set way back in 1887, when Hurricane Eighteen and Tropical Storm Nineteen were both active on December 8. There were three years that had simultaneous November named storms: 1932, 1961, and 2001.

Next update
I'll have more late Saturday morning.

Jeff Masters

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...TWELFTH HURRICANE OF THE SEASON BEARING DOWN ON ST. LUCIA
AND ST. VINCENT...

SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...13.3N 60.7W
ABOUT 40 MI...65 KM SSE OF ST. LUCIA
ABOUT 35 MI...55 KM E OF ST. VINCENT
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/HR
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 15 MPH...24 KM/HR
MINIMUM CENTRAL PRESSURE...993 MB...29.32 INCHES
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the eye approaching Saint Vincent and the Grenadines

http://www.meteo.fr/temps/domtom/antilles/pack-public/animation/animMOSAIC2.html
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This is the best storm I could find that traveled across the Caribbean so late in the season, this is 1895


It's just rare and not likely for Tomas to reach the Western Caribbean without getting pulled.
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...Tomas causes damage on Barbados...now heading toward the northern Windward Islands at near-hurricane strength...


summary of 800 am AST...1200 UTC...information
----------------------------------------------
location...13.1n 60.1w
about 70 mi...115 km se of St. Lucia
about 70 mi...115 km E of St. Vincent
maximum sustained winds...70 mph...110 km/hr
present movement...WNW or 300 degrees at 15 mph...24 km/hr minimum central pressure...993 mb...29.32 inches


watches and warnings
--------------------
changes with this advisory...

none.

Summary of watches and warnings in effect...

a Hurricane Warning is in effect for...
* Barbados
* St. Vincent and The Grenadines
* St. Lucia
* Martinique

a Tropical Storm Warning is in effect for...
* Trinidad and Tobago
* Grenada
* Dominica

a Hurricane Warning means that hurricane conditions are expected
somewhere within the warning area...in this case within 12 hours.
Preparations to protect life and property should be complete.

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area...in this case within
the next 12 hours.

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 AST...1200 UTC...the center of Tropical Storm Tomas was located near latitude 13.1 north...longitude 60.1 west.

Tomas is moving toward the west-northwest near 15 mph...24 km/hr...and this motion is expected to continue with a gradual decrease in forward speed tonight and Sunday. On the forecast track...the center of Tomas will pass through the northern Windward Islands this afternoon and enter the eastern Caribbean Sea by tonight.

Maximum sustained winds have are near 70 mph...110 km/hr...with higher gusts. Strengthening is forecast during the next 48 hours...and Tomas is expected to become a hurricane later today.

Tropical storm force winds extend outward up to 140 miles...220 km from the center. During the past hour...a wind gust to 63 mph...100 km/hr...was reported on Barbados. Information from the Barbados meteorological service indicates that damage to homes and downed power lines have been reported on the island.

The minimum central pressure recently estimated by an Air Force Reserve reconnaissance aircraft was 993 mb...29.32 inches.


Hazards affecting land
----------------------
wind...tropical storm conditions are occurring on Barbados...and will spread across the remainder of the warning area this morning.
Hurricane conditions are expected within the Hurricane Warning area later this morning.

Rainfall...Tomas is expected to produce total rain accumulations of 3 to 5 inches...with possible isolated maximum amounts of 8 inches...across portions of the windward and southern Leeward Islands.

Storm surge...a dangerous storm surge will raise water levels by as much as 1 to 3 feet above normal tide levels within areas of onshore flow. The surge will be accompanied by large and potentially destructive waves.


Next advisory
-------------
next complete advisory...1100 am AST.
$$
Forecaster Stewart/cangialosi


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I think a flora like track is very possible hopefully Tomas won't be anywhere near as devestating
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Quoting cat5hurricane:

Trick or Treat!


you got it
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27 minutes since the last HDOB.
Member Since: June 9, 2007 Posts: 4 Comments: 15950

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I think the HH is having problems again... with their reports.. its been to long without an update again... they should be at the Vortex position.
Member Since: October 1, 2007 Posts: 81 Comments: 26516
Barbados WunderMap®
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Quoting cat5hurricane:

Probably not Charlie. I don't see this getting anywhere near FL.


cant totally rule it out though these things can pull tricks on us
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i dont think that will happen
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Quoting Patrap:
12z Early Cycle NHC model tracks
Tomas
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)







the models this morn are showing steady weakening
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Amazing, the numbers could total to this..
20/12/6
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Member Since: October 1, 2007 Posts: 81 Comments: 26516
12z Early Cycle NHC model tracks
Tomas
Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)





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Quoting hydrus:
When do you start working at the NHC?..:)

Hey, I never claimed to be good--just stubborn and persistent enough to hold out until luck kicked in. ;-)
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Quoting reedzone:
Ummm... Why did the opposite happen, Tomas was supposed to be a Hurricane, not Shary lol.. Weird season. Well the Hurricane streak continues from Otto to Shary and most likely Tomas later today.

AL, 21, 2010103012, , BEST, 0, 131N, 601W, 65, 993, HU
Member Since: June 9, 2007 Posts: 4 Comments: 15950
Quoting reedzone:
Ummm... Why did the opposite happen, Tomas was supposed to be a Hurricane, not Shary lol.. Weird season. Well the Hurricane streak continues from Otto to Shary and most likely Tomas later today.


Its been a Hurricane for about an hour now reed
Member Since: October 1, 2007 Posts: 81 Comments: 26516
with 2 hurricanes is it Oct 30 or Aug 30? lol
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Tomas is not finished with Barbados yet.
LinkIRLoop
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Quoting Thundercloud01221991:
what is that wave SE of Thomas... will it follow Thomas?


i dont think so but Thomas wasnt thought to develop for a time either so lets watch it and see what it does
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Cloud pattern has become ragged in the past 6-12 hours.


Member Since: June 9, 2007 Posts: 4 Comments: 15950
Ummm... Why did the opposite happen, Tomas was supposed to be a Hurricane, not Shary lol.. Weird season. Well the Hurricane streak continues from Otto to Shary and most likely Tomas later today.
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Quoting jasoniscoolman2010xo:
wow!!look at the high wind shear moving south..


its not forecasted to impact Thomas though
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Quoting kmanhurricaneman:
that was kmanislander, however iwas telling everyone based on radar imagery the coc is moving due west and got flamed for it.
Right. Past time for a coffee....
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this could follow a paloma or mabie a charley type path is my thinking right now
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1) Has any North Atlantic storm south of 15 degrees north spun up from invest to hurricane this quickly before (and with such a large wind field?)

2) Did Tomás originate in a wave that traveled over from Africa? Given the time of year, that would be an amusing factoid, if so.

3) Any thoughts about the blob near 5N 43W? Is this the next one?
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Quoting HurricaneDean07:
So Tomas went north of Barbados
and is now turning west again.

Nope went just south of Barbados.
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Quoting kmanislander:


I was hoping we wouldn't see one like Tomas this year. Virtually every system that has come up from that origin point has done a lot of damage along the way. One blessing is the TCHP has fallen off but not enough to prevent this becoming a major I am afraid.


And indicators point to Hispaniola.
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me too see yah all later......
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Quoting kmanhurricaneman:
that was kmanislander, however iwas telling everyone based on radar imagery the coc is moving due west and got flamed for it.


Due West is pretty close...YOu should now by now that Orca knows everything.....LOL.....See ya all.
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Quoting Neapolitan:

I can proudly say--now--that I steadfastly stuck with 20-12-6, so all that's left is for Tomas to make major--almost a lock--and one more TS to form by December 31.
When do you start working at the NHC?..:)
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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