Tomas gradually strengthening; 14 dead in St. Lucia from the storm

By: Dr. Jeff Masters , 2:58 PM GMT on November 02, 2010

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The islands of St. Lucia, Barbados, and St. Vincent and the Grenadines continue to assess damage and clean up after Hurricane Tomas pounded the Lesser Antilles as a strengthening Category 1 hurricane with 90 - 95 mph winds on Saturday. St. Lucia was hardest hit, with fourteen people dead, many more missing, and damage estimated at $100 million--about 10% of the nation's GDP. Damage on neighboring St. Vincent was estimated at $62 million, which is 4% of that nation's GDP. The storm damaged 1,200 houses, and the northern half of the island, where most of the crops are, was badly hit, with no banana trees left standing and the plantain crop wiped out. Banana production employs 60% of the workforce on St. Vincent, and accounts for more than 50% of their exports. Also hard-hit was Barbados, where damage estimates are at $55 million, 1.5% of the nation's GDP. Tomas may be the most damaging storm to affect the island since Hurricane Janet of 1955. The havoc wreaked by Tomas in the Lesser Antilles makes is likely that the name Tomas will be retired from the list of active hurricane names in the Atlantic.


Figure 1. Torrential rains from Tomas triggered massive flooding on St. Lucia that destroyed several bridges and severely damaged roads. Image credit: St. Lucia Star.

Tomas gradually strengthening
Satellite loops of Tomas show a considerably more organized storm than yesterday, with a modest but increasing amount of heavy thunderstorm activity. However, low-level spiral bands are limited, and upper-level outflow is weak, and Tomas is not in danger of building an eyewall today. Curacao radar shows that the echoes from Tomas are disorganized, with no spiral banding apparent. Wind shear has declined to a moderate 10 -15 knots and the atmosphere in the Caribbean has moistened over the past day, allowing Tomas to re-organize. A hurricane hunter aircraft is on its way to Tomas this morning, and will have a better estimate of the storm's strength by early this afternoon.


Figure 2. Curacao radar at 10:07am EDT on Tuesday, November 2, 2010, showed a large area of rain associated with Tomas over the central Caribbean, but these echoes were poorly organized.

Track forecast for Tomas
The ridge of high pressure pushing Tomas to the west has weakened, allowing Tomas to slow down slightly to a forward speed of 10 mph this morning. This speed will decrease further to 5 mph tonight, as a trough of low pressure approaches the eastern U.S. and breaks down the ridge. By Wednesday, the trough to Tomas' north should be able to pull the storm to the northwest. Tomas' outer spiral bands will bring heavy rains to southwestern Haiti and eastern Jamaica beginning on Thursday night. The computer models have come into better agreement that Tomas will turn more to the north-northeast by Friday, with Haiti or Jamaica the most likely landfall locations. NHC is giving Port-au-Prince, Haiti, a 50% chance of receiving tropical storm force winds, and a 6% chance of hurricane force winds. These odds are 45% and 7%, respectively for Kingston, Jamaica, and 23% and 3% for Santo Domingo in the Dominican Republic.

Tomas may stall
The models are increasingly suggesting the once Tomas begins moving to the north-northeast, the trough pulling the storm that direction will lift out, stranding Tomas in a region of weak steering currents. Tomas may then wander and dump heavy rains for several days, Saturday through Monday. Given recent model trends, I believe this is likely, but the exact location where Tomas might be stranded is uncertain. The NOGAPS model gives a nightmare scenario for Haiti, with Tomas remaining stationary just off the coast from Port-Au-Prince as a hurricane for many days. The UKMET stalls Tomas over the Turk and Caicos Islands, while the GFS, GFDL, and ECMWF models predict Tomas will stall several hundred miles north of Hispaniola and drift eastwards. It's reasonable to go with the model consensus and predict Tomas will pass over western Haiti and stall far enough north of the nation so that heavy rains will not linger over Hispaniola for many days. The uncertainties in the track forecast are greater than usual, though.

Intensity forecast for Tomas
Wind shear as diagnosed by the SHIPS model has dropped to the moderate range, 10 - 15 knots, and is predicted to stay low to moderate, 5 - 15 knots, for the remainder of the week. The relaxation of shear should allow Tomas to continue to re-organize over the next few days. Aiding this process will be an increasingly moist atmosphere. Dry air has decreased significantly over the past 24 hours, as seen on water vapor satellite imagery, and the models predict a very moist atmosphere will surround Tomas for the remainder of the week. With SSTs at a record warm 29.5°C and a very high ocean heat content, there is a substantial danger that Tomas will undergo a period of rapid intensification once it rebuilds its inner core and establishes an eyewall. This is not likely to happen today, but could occur as early as Wednesday night. This may give Tomas sufficient time to intensify into a major hurricane before landfall in Haiti or Jamaica, as predicted by the GFDL model. The most reasonable intensity forecast at this point is to call for a landfall on Friday at Category 2 strength, but Tomas could easily be anywhere from Category 1 to Category 3 hurricane strength on Friday. NHC is giving Tomas a 19% chance of reaching Category 3+ strength; I believe these odds are higher, 40%. With the atmosphere expected to be very moist, it is likely that Tomas will dump very heavy rains of 4 - 8 inches over much of Haiti, even if Tomas strikes as a tropical storm. Rains of this magnitude are capable of causing heavy loss of life due to extreme floods running down Haiti's deforested mountain slopes. Portlight.org is preparing to send their mobile kitchen with enough food to feed 500 people per day, if Tomas continues on its current forecast path.


Figure 3. Plot of all Category 1 and stronger hurricanes to pass within 50 miles of Barbados since reliable record keeping began in 1851. Image credit: NOAA Coastal Services Center.

Barbados hurricane history
Tomas is the strongest hurricane to affect Barbados since Category 3 Hurricane Allen of 1980, which passed just north of the island. Allen did $4 million in damage, compared to Tomas' $55 million. The deadliest hurricane in Barbados history was the Category 5 Great Hurricane of 1780, which killed approximately 4500 people on the island, and leveled every building, including the stone governor's mansion. The Great Hurricane of 1780 was also the Atlantic's deadliest hurricane of all-time, with 22,000 fatalities, mostly in the Lesser Antilles Islands.

Next update
I'll have an update Wednesday morning.

Jeff Masters

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I am starting to wonder if it isn't begging to strengthen rapidly at 13 and 73..seems like convection is wrapping up rapidly there.
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Link
ECFL rain showers... moving in off the ocean... motion wnw... associated with the seabreeze south of Daytona... not much south of Cocoa Beach... sorry FP...
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Best case senario other than dissipation is for Tomas to travel along 75 west in the Windward passage between Jamaica and Haiti and then take the sharp NE turn between Eastern Cuba and Haiti and then out to sea, missing the T & C Islands as well.

Far fetched? Some of the models are very close to that.
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hey stormwatcherCI well you know what they say if them birds fly inland storm is coming
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Member Since: October 1, 2007 Posts: 81 Comments: 26516
153. JRRP
Link
interesting
Member Since: August 16, 2007 Posts: 0 Comments: 6213
Quoting uncljbnd:
Undertaker..I got married at Half Moon Bay in Mobay.


Half Moon is a very nice place
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Quoting scott39:
This would change the track a little.



If that is the center..then it isn't closed.
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I don't know how it affects the tropical weather, but I can tell you when the cold front came through Southern California on Friday, it was much weaker than expected. If that translates to a less amplified trough, the turn should be less pronounced.

Hopefully that also means he'll continue west to places much better able to deal with the situation than poor Haiti.

My best wishes for safety and recovery to all who have been and are yet to be affected.
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Quoting Skyepony:
Looks like center fix ~ 13.2N 74.0W
This would change the track a little.
Tomas isn't going to be a threat to anyone if this keeps up.

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Quoting WeatherfanPR:


Tomas is not a concern to Puerto Rico anymore so don't worry.


Not true.
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Due to fly out of Jamaica to Europe tomorrow and leave my yacht for the first time in 2 years, not looking like a good idea. might just have to cancel the flight!
As much as i dont want Thomas to hit Jmaaica directly it would be terrible for Haiti.
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Quoting Jeff9641:
Finally some heavy rain in E C FL. Didn't think I would get this much today but boy is it pouring at times.


Where are you in EC FL? I'm in PSL/FortPierce and it is bone dry.
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Quoting VAbeachhurricanes:
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 02 NOV 2010 Time : 164500 UTC
Lat : 12:35:41 N Lon : 72:41:07 W


CI# /Pressure/ Vmax
3.9 / 991.9mb/ 63.0kt


Final T# Adj T# Raw T#
3.9 4.4 5.8


Latitude bias adjustment to MSLP : +3.5mb

Estimated radius of max. wind based on IR : 20 km

Center Temp : -36.4C Cloud Region Temp : -69.0C

Scene Type : EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : 0.5T/hour
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

what?!


Facepalm for ADT. That is definitely not an eye..... XP
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Thomas is still a disorganized system. It should develop more tonight thru the next couple of days but wont be no hurricane tonight like Reedzone hypes on each system.. It could become a hurricane later Weds into Thurs. Too early to tell the strength of the system in days 2-3.

Short term movement will slow tonight into Weds and will begin a drift NE by later Thurs as the eastern seaboard trough digs. If the trough digs further south into eastern Cuba.. Thomas will move NE thru Haiti. If the trough does dig as deep or moves faster, Thomas may move more ENE near Haiti-DR and even come closer to Puerto Rico by Sunday. Trough is key to everything here.
Short term,- West movement and slowing down tonight. Not much movement on Weds then a drift NNE-NE on Thurs-Friday.
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Quoting sunlinepr:
Interesting that GFS places Tomas passing N of PR, but moving SE somewhat close to the N coast...



Tomas is not a concern to Puerto Rico anymore so don't worry.
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Quoting serialteg:
surf in puerto rico from tomas



Aguadillas lighthouse at Ramey???
Member Since: August 2, 2010 Posts: 21 Comments: 9882
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 02 NOV 2010 Time : 164500 UTC
Lat : 12:35:41 N Lon : 72:41:07 W


CI# /Pressure/ Vmax
3.9 / 991.9mb/ 63.0kt


Final T# Adj T# Raw T#
3.9 4.4 5.8


Latitude bias adjustment to MSLP : +3.5mb

Estimated radius of max. wind based on IR : 20 km

Center Temp : -36.4C Cloud Region Temp : -69.0C

Scene Type : EYE

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : 0.5T/hour
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

what?!

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I also think Tomas forward speed has increased rather than slowed as forcasted, that is also bad news, that can make all the difference with timing!
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Quoting serialteg:
surf in puerto rico from tomas

Dang, I know where I want to be.
Member Since: August 27, 2009 Posts: 0 Comments: 525
Interesting that GFS places Tomas passing N of PR, but moving SE somewhat close to the N coast...

Member Since: August 2, 2010 Posts: 21 Comments: 9882
Quoting serialteg:
surf in puerto rico from tomas



The ligthhouse at the back of this picture should be the one in Rincon, rigth???
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133. JRRP
Quoting Seastep:
You can see the circulation at 12N/76W on RGB.

Link

That would be a game changer.

nop
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I still think the further south and west Tomas goes, the more Jamaica and Eastern Cuba is in play, as for us here in the Caymans, i wouldn't holler before we get out of the woods.
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Quoting aprinz1979:


Levi, Great analysis!

What's your take on Tomas stalling for a few days over haiti?

Thanks,


A stalling and a reluctance to recurve out to the northeast is possible if Tomas remains weak, but if he strengthens into a formidable hurricane then he will likely not stall, but will make his way gradually out to the northeast. I don't think this will stall over Haiti, but it will be bad enough already.
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Quoting Caymanite:
Hi Levi, thanks for your very informative daily "Tid-Bits". Please say what % you would give for the Cayman Islands being impacted by Tomas.--TIA.


Very low.
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TropicalStormTomas's heading turned northward to (8.1degrees west of) WestNorthWest
from it's previous heading of (4.5degrees south of) WestSouthWest
TS.Tomas's average speed moving between its last 2 reported positions increased to ~9.3mph(~15km/h) from its previous travel speed of ~5mph(~8km/h)
TS.Tomas
1Nov. 03pmGMT - 13.6n68.7w - 45mph_(~72.4km/h) - 1005mb - NHC.Adv.#14
1Nov. 06pmGMT - 13.4n69.2w - 40knots.(~74.1km/h) - 1005mb - ATCF
1Nov. 09pmGMT - 13.4n69.7w - 45mph_(~72.4km/h) - 1005mb - NHC.Adv.#15
2Nov. 12amGMT - 13.5n70.4w - 40knots.(~74.1km/h) - 1005mb - ATCF
2Nov. 03amGMT - 13.5n70.8w - 45mph_(~72.4km/h) - 1005mb - NHC.Adv.#16
2Nov. 06amGMT - 13.6n71.3w - 40knots.(~74.1km/h) - 1003mb - ATCF
2Nov. 09amGMT - 13.5n72.0w - 50mph_(~80.5km/h) - 1003mb - NHC.Adv.#17
2Nov. 12pmGMT - 13.4n72.2w - 45knots.(~83.3km/h) - 1003mb - ATCF
2Nov. 03pmGMT - 13.5n72.6w - 50mph_(~80.5km/h) - 1003mb - NHC.Adv.#18

Copy&paste 13.6n68.7w, 13.4n69.2w, 13.4n69.7w, 13.5n70.4w, 13.5n70.8w-13.6n71.3w, 13.6n71.3w-13.5n72.0w, 13.5n72.0w-13.4n72.2w, 13.4n72.2w-13.5n72.6w, kin, cya, aua into the GreatCircleMapper for a look at the headings and the distances traveled over the last 12^hours.
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100% agree scott
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LLC is about 13.5N and 74.1W moving W right now
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123. JRRP
Member Since: August 16, 2007 Posts: 0 Comments: 6213
Undertaker..I got married at Half Moon Bay in Mobay.
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13 and 74.5 is the COC
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120. JRRP
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Quoting Inactivity:


What are the strongest winds they have found?

Normally in the NE semi-circle :O)
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Quoting Seastep:
You can see the circulation at 12N/76W on RGB.

Link

That would be a game changer.


That it would. Throw all of models out the window and start again. Nice thing is that I believe Haiti would be out of the picture then.
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Quoting stormpetrol:

This is stronger than 50mph, the are just starting to investigate the system, they have crisscross the system in all quandrants, just wait and see!
Hey StormPetrol. Kinda weird I am seeing the man o' war all flying inland.
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You can see the circulation at 12N/76W on RGB.

Link

That would be a game changer.
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Quoting stormwatcherCI:
Where in Jamaica are you located ? Have many friends there and a grand-daughter who is currently in Kingston.


I am in Montego Bay
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Quoting Seastep:
Hmph. **scratches head*** Looks to be way elongated? 12.5N/76W?

Hope HH checks that out.



Odd winds on the first penetration. However, surely indicative of a weak, broad circulation.
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Hmph. **scratches head*** Looks to be way elongated? 12.5N/76W?

Hope HH checks that out.

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Hi Levi, thanks for your very informative daily "Tid-Bits". Please say what % you would give for the Cayman Islands being impacted by Tomas.--TIA.
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Quoting stormpetrol:
winds are always lightest within the center.


What are the strongest winds they have found?
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Quoting Undertaker:
I strongly believe Haiti will only get rain which will still be bad but for some reason I see jamaica getting hit from the southwest of the island. It's just a feeling i have ever since I saw thomas develop. We still have places here in Jamaica still underwater from Tropical storm Nicole. And every update I see the forecast track shift a little further west. If it reaches between 75w - 80w and still below 15n I see no reason why we would not get a direct hit.

Any comments.
Where in Jamaica are you located ? Have many friends there and a grand-daughter who is currently in Kingston.
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Quoting Seastep:


They are finding some TS force winds.

I expect them to lower again to a minimal TS at 2pm unless they find something else.

Doubt they'll drop him to TD status.

This is stronger than 50mph, the are just starting to investigate the system, they have crisscross the system in all quandrants, just wait and see!
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Quoting Levi32:


Something to watch for later, but not a major concern right now.


Levi, Great analysis!

What's your take on Tomas stalling for a few days over haiti?

Thanks,
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