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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Quoting Orcasystems:
Slight model shift to the west, bringing Jamaica more into play.

HH looks like it got bored and is heading home.

Complete Update


AOI
AOI AOI AOI

AOI AOI AOI

TSPIN BUSTED FORECAST ALIBI


News Haiti needed, looks like they won't get a direct impact.
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207. JLPR2
Quoting FSUCOOPman:


What constitutes as "developed"?

Simply designated as a TD or higher prior to entering the Caribbean?


I believe a TD is sufficient.
Member Since: September 4, 2007 Posts: 7 Comments: 8499
Quoting CyclonicVoyage:


Look at my post 201

Quite significantly off track.


I agree....but I think the alteration.. if its made.. will correct for being south of track... big if
Member Since: October 1, 2007 Posts: 81 Comments: 26511
21L/TS/T/CX
mark
13.43N/74.76W
IR ANIM STILLIMAGE VIS. WV ANIM IMAGE
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting Orcasystems:
Complete Update

Slight model shift to the west, bringing Jamaica more into play.

HH looks like it got bored and is heading home.



Look at my post 201

Quite significantly off track.
Member Since: Posts: Comments:
Slight model shift to the west, bringing Jamaica more into play.

HH looks like it got bored and is heading home.

Complete Update


AOI
AOI AOI AOI

AOI AOI AOI

TSPIN BUSTED FORECAST ALIBI
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting reedzone:
Tomas is at 50 mph. Convection sustaining and increasing, outflow is impressive. 50 mph. is a good call. I expect Tomas to strengthen into a Hurricane late tonight.


Pressure is up to 1007.

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Quoting tornadodude:


B....


could tell by your profile picture... ;)
Member Since: September 6, 2007 Posts: 0 Comments: 6068
Quoting XXStormXX:
Say "A if you are a guy and say "B if you are a girl, it's a survey!!

Thanks

A for me

Tomas is looking great out there


B....
Member Since: June 28, 2006 Posts: 24 Comments: 8201
hey guys


feel free to check out my new blog entry
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Any word on relief efforts in St. Lucia?
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Quoting reedzone:
Ughh hate this rain!! Need to go vote and there is no car! Hmm sun is starting to pop out, maybe it'll clear up. I need to vote, it's crucial!


Yes it is. Bright and sunny here in South Florida, not expecting rain until tomorrow evening.
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somehow, I don't think this is what John said....


From the Miami Herald:

At 11 a.m. Tuesday, the National Hurricane Center said Tomas had grown stronger and more organized, with sustained winds at 50 mph, and remained on a track toward Haiti's southern coast. The storm was was expected to slow and begin curving north late Wednesday or early Thursday, with Haitians likely to begin feeling its effects in the early morning hours of Friday.

John Cangialosi, a hurricane specialist at the National Hurricane Center in West Miami-Dade, said the powerful center of the storm could shift significantly to the east toward Jamaica or west toward the Dominican Republic before it makes landfall.

http://www.miamiherald.com/2010/11/02/1903580/in-cross-hairs-of-a-storm-haiti.html
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Tomas is at 50 mph. Convection sustaining and increasing, outflow is impressive. 50 mph. is a good call. I expect Tomas to strengthen into a Hurricane late tonight.
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Ughh hate this rain!! Need to go vote and there is no car! Hmm sun is starting to pop out, maybe it'll clear up. I need to vote, it's crucial!
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im suprised tommys not a td,less orgainized that yesterday,more convection yes....but tommys got a rendezvous w/CA imo...
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Quoting Jeff9641:
We are going from Drought to Floods here in Seminole County north of orlando. Now at 1.76" in Wekiva Springs.


Well don't hog it all up, Jeff- bring some down to Port St. Lucie, lol.
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It amazes me what Tomas has looked like the last few days, considering how well organized he was when he first formed
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TWC (Tropical Update) says "Tomas is currently on aweakening trend".
"More favorable conditions earlier today."
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180. Jax82
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Tomas is very weak right now
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Thomas is VERY ill defined ATM.

Remarks Section - Additional Remarks...
RAINING AT THE FIX POSN CALM BELOW
SFC WNDS LGT AND VAR INBOUND LEG
RELIED ON TEMP RISE FOR FIX
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Quoting Inactivity:
Anyone have Recon readings, what is the strongest winds they have picked up in the past 3 hours?


This is current.

Storm information valid as of: Tuesday, November 2, 2010 18:00 Z
Coordinates: 13.4N 74.2W (View Map or View Storm Centered Satellite Image)
Location: 225 miles (362 km) to the NNE (24°) from Cartagena, Colombia
Distance Calculator: How far away is this storm from me?
Pressure (MSLP): 1006 mb (29.71 inHg | 1006 hPa)
Sustained wind speed (1 min. avg.): 35 knots (40 mph | 18 m/s)
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175. JRRP
Tomas is moving WSW
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Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 2nd day of the month at 18:38Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Storm Number & Year: 21L in 2010
Storm Name: Tomas (flight in the North Atlantic basin)
Mission Number: 8
Observation Number: 10
A. Time of Center Fix: 2nd day of the month at 18:21:50Z
B. Center Fix Coordinates: 13°26'N 74°22'W (13.4333N 74.3667W)
B. Center Fix Location: 223 miles (359 km) to the NNE (21°) from Cartagena, Colombia.
C. Minimum Height at Standard Level: 1,474m (4,836ft) at 850mb
D & E. Estimated (by SFMR or visually) Maximum Surface Wind: Not Available
F. Maximum Flight Level Wind Inbound: From 349° at 12kts (From the N at ~ 13.8mph)
G. Location of Maximum Flight Level Wind Inbound: 35 nautical miles (40 statute miles) to the SW (219°) of center fix
H. Minimum Sea Level Pressure: 1007mb (29.74 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 18°C (64°F) at a pressure alt. of 1,510m (4,954ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 19°C (66°F) at a pressure alt. of 1,520m (4,987ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 3°C (37°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 7 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 30kts (~ 34.5mph) in the northwest quadrant at 17:44:20Z
Remarks Section - Additional Remarks...
RAINING AT THE FIX POSN CALM BELOW
SFC WNDS LGT AND VAR INBOUND LEG
RELIED ON TEMP RISE FOR FIX
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unusual appearance on visiable oval shaped but looking like its ready to windup. prico might be a the strong part of the storm if he is moving ese at the end of the run
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Quoting sunlinepr:
Interesting that GFS places Tomas passing N of PR, but moving SE somewhat close to the N coast...

That's not a good thing
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Anyone have Recon readings, what is the strongest winds they have picked up in the past 3 hours?
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Quoting lordhuracan01:


i think this will be the same tragedy, like noel y olga in 2007...


Saddest part is, how can someone who lives in a tent prepare for something like this? It's very deppresing
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Quoting JLPR2:


Tomas is already a developed tropical system that's why it doesnt apply. :)


What constitutes as "developed"?

Simply designated as a TD or higher prior to entering the Caribbean?
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Quoting WeatherfanPR:
Let's pray to God so the Countries of Jamaica, Haiti and Dominican Republic don't suffer too much from Tomas. Let's hope they will be better prepared for this one.


i think this will be the same tragedy, like noel y olga in 2007...
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166. JRRP
moving SE at the end of the run
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I think it is rapidly strengthening and starting to make a bit of a move to the NW
Member Since: July 22, 2010 Posts: 0 Comments: 67
Tomas is less then 50 miles from exiting the western border of the (play creepy music here) Hurricane Graveyard
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163. JLPR2
Quoting FSUCOOPman:
So... I'm kind of confused on how the John Hope rule would or would not apply to Tomas. I mean he kind of was developed AS he was heading into the Caribbean, but he's obviously weakened substantially in the Caribbean, and now he's forecast to ramp back up... It's kind of like he's the exception to the rule and tap dancing all over every possible gray area of the rule's interpretation... :-P

Not really looking for an answer, just kind of thinking out loud...


Tomas is already a developed tropical system that's why it doesnt apply. :)
Member Since: September 4, 2007 Posts: 7 Comments: 8499
So... I'm kind of confused on how the John Hope rule would or would not apply to Tomas. I mean he kind of was developed AS he was heading into the Caribbean, but he's obviously weakened substantially in the Caribbean, and now he's forecast to ramp back up... It's kind of like he's the exception to the rule and tap dancing all over every possible gray area of the rule's interpretation... :-P

Not really looking for an answer, just kind of thinking out loud...
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161. JLPR2
Quoting Skyepony:
Looking at recon progress & This morning's ASCAT pass just over an hour ago..Tomas not looking so tight. Recon passed through 1mb lower area also showing a nice switch in winds around 13.45N 72.0W



In other words Tomas is looking good, but not doing good. XD
Member Since: September 4, 2007 Posts: 7 Comments: 8499
159. Skyepony (Mod)
Looking at recon progress & This morning's ASCAT pass just over an hour ago..Tomas not looking so tight. Recon passed through 1mb lower area also showing a nice switch in winds around 13.45N 72.0W

Member Since: August 10, 2005 Posts: 161 Comments: 37346
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.
Member Since: July 22, 2010 Posts: 0 Comments: 67

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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.