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 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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Product: Air Force Tropical RECCO Message (URNT11 KNHC)
Transmitted: 2nd day of the month at 16:57Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Storm Number: 21
Storm Name: Tomas (flight in the North Atlantic basin)
Mission Number: 8
Observation Number: 05

Mandatory Data...

Observation Time: Tuesday, 16:55Z
Radar Capability: Yes
Aircraft Altitude: Below 10,000 meters
Coordinates: 12.9N 73.7W
Location: 212 miles (341 km) to the NE (36°) from Cartagena, Colombia.
Turbulence: None
Conditions Along Flight Route: In the clear
Pressure Altitude: 1,520 meters
Flight Level Wind: 5 knots (~ 5.8 mph) (Bearing was unavailable.)
- The above is a spot wind.
- Winds were obtained using doppler radar or inertial systems.
Flight Level Temperature: 20°C
Flight Level Dew Point: 6°C
Weather (within 30 nautical miles): Thunderstorm(s)
850 mb Surface Altitude: 1,485 geopotential meters

Optional Data...

Estimated Surface Wind: From 260° at 20 knots (From the W at ~ 23.0 mph)

Remarks Section...

Surface Wind Speed (likely by SFMR): 30 knots (~ 34.5mph)
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Quoting Inactivity:


It suddenly has tropical depression winds? How?


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.
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Quoting Inactivity:


It suddenly has tropical depression winds? How?
winds are always lightest within the center.
Member Since: April 29, 2007 Posts: 0 Comments: 7631
Quoting Skyepony:
Some Tomas model error stats..

Average Position Error (nm) Tomas models
model Error Trend 24hr Error 48hr Error 72hr Error Day 4 Error Day 5 Error
CMC INCREASING 63.5 98.3 124.3 242 304.9
UKMT DECREASING 64.3 95.1 95.3 -1 -1
AEMI INCREASING 65.4 108.6 166.7 -1 -1
GFDL INCREASING 67.7 142.7 143.1 -1 -1
AEMN DECREASING 68.3 109.9 167.4 -1 -1
OFCL INCREASING 71.1 107.9 113.6 155.1 -1
HWRF DECREASING 74.3 155.7 186.5 265.9 400.3
KHRM DECREASING 82.1 246.2 411.4 -1 -1
LBAR INCREASING 102.4 195.2 191.2 297.1 558.8
BAMD INCREASING 110.4 198.6 197.5 152.9 184.8
MM5B INCREASING 173.3 350 170.4 274.3 527.1
MM5E INCREASING 236.5 508.1 472.2 -1 -1


That's comforting.. Not...

No wondner the projected track has low confidence.
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Quoting stormpetrol:
Time: 16:37:30Z
Coordinates: 13.2N 74.0667W
Acft. Static Air Press: 843.4 mb (~ 24.91 inHg)
Acft. Geopotential Hgt: 1,554 meters (~ 5,098 feet)
Extrap. Sfc. Press: 1006.7 mb (~ 29.73 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 29° at 1 knots (From the NNE at ~ 1.1 mph)
Air Temp: 20.8°C (~ 69.4°F)
Dew Pt: 4.8°C (~ 40.6°F)
Peak (10s) Flt. Lvl. Wind: 3 knots (~ 3.4 mph)
SFMR Peak (10s) Sfc. Wind: 31 knots (~ 35.6 mph)
SFMR Rain Rate: 8 mm/hr (~ 0.31 in/hr)
(*) Denotes suspect data

probably roughly where the center is!


It suddenly has tropical depression winds? How?
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that center looks correct to me...track is going to have to go left. This is looking more like Jamiaca/Cuba now
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ASCAT on the C Atl wave surprises me. Possible invest soon, imo.

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Still rather disorganized.

Give it another day.

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I would say some put alot of emphasis on pressure, while it is indicative of a stenghtening system you can find a system with stronger winds and higher pressure & vice versa!
Member Since: April 29, 2007 Posts: 0 Comments: 7631
Time: 16:37:30Z
Coordinates: 13.2N 74.0667W
Acft. Static Air Press: 843.4 mb (~ 24.91 inHg)
Acft. Geopotential Hgt: 1,554 meters (~ 5,098 feet)
Extrap. Sfc. Press: 1006.7 mb (~ 29.73 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 29° at 1 knots (From the NNE at ~ 1.1 mph)
Air Temp: 20.8°C (~ 69.4°F)
Dew Pt: 4.8°C (~ 40.6°F)
Peak (10s) Flt. Lvl. Wind: 3 knots (~ 3.4 mph)
SFMR Peak (10s) Sfc. Wind: 31 knots (~ 35.6 mph)
SFMR Rain Rate: 8 mm/hr (~ 0.31 in/hr)
(*) Denotes suspect data

probably roughly where the center is!
Member Since: April 29, 2007 Posts: 0 Comments: 7631
Quoting Inactivity:
Any chance we will see Alpha this year?

Yes. I saw the 1-in-10,000 odds someone else posted, but I'll say there's a 50% chance.
Member Since: November 8, 2009 Posts: 4 Comments: 13442
Tomas should be a hurricane by Thursday morning. He has a lot of time to get there. The convection looks to be more sustainable now that he's out of the low-level divergent zone which was killing him.
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95. Skyepony (Mod)
Looks like center fix ~ 13.2N 74.0W
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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.
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1007mb is the lowest I have seen

tells me this system is weaker than what even the NHC thought
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Quoting Hurricanes101:
I am not seeing any impressive winds or pressure from recon


Looks to be rather broad and loose now which is to be expected after almost no convection for nearly 48 hours. This has a full 36-48 hours to organize and come back before the real and rapid strengthening will likely begin.
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Quoting Inactivity:
Any chance we will see Alpha this year?


.0001%
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Quoting stormpetrol:
Time: 16:33:00Z
Coordinates: 13.3667N 73.9W
Acft. Static Air Press: 842.0 mb (~ 24.86 inHg)
Acft. Geopotential Hgt: 1,577 meters (~ 5,174 feet)
Extrap. Sfc. Press: 1007.3 mb (~ 29.75 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 185%uFFFD at 7 knots (From the S at ~ 8.0 mph)
Air Temp: 21.7%uFFFDC (~ 71.1%uFFFDF)
Dew Pt: 5.8%uFFFDC (~ 42.4%uFFFDF)
Peak (10s) Flt. Lvl. Wind: 9 knots (~ 10.3 mph)
SFMR Peak (10s) Sfc. Wind: 25 knots (~ 28.7

lowest pressure so far, looks like the coc might be even further south and west than previously thought


Most likely that is the center, or close to, as SW winds were found just after @ 16:34:00Z 13.333N 73.917W

Could also be a little further west, which would not surprise me at all.
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surf in puerto rico from tomas

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Any chance we will see Alpha this year?
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Quoting stormpetrol:
Time: 16:33:00Z
Coordinates: 13.3667N 73.9W
Acft. Static Air Press: 842.0 mb (~ 24.86 inHg)
Acft. Geopotential Hgt: 1,577 meters (~ 5,174 feet)
Extrap. Sfc. Press: 1007.3 mb (~ 29.75 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 185° at 7 knots (From the S at ~ 8.0 mph)
Air Temp: 21.7°C (~ 71.1°F)
Dew Pt: 5.8°C (~ 42.4°F)
Peak (10s) Flt. Lvl. Wind: 9 knots (~ 10.3 mph)
SFMR Peak (10s) Sfc. Wind: 25 knots (~ 28.7

lowest pressure so far, looks like the coc might be even further south and west than previously thought


SW wind was found, this system is not that impressive still from what I am seeing
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16:33:00Z 13.367N 73.900W

1007.3 mb
(~ 29.75 inHg)

From 185° at 7 knots
(From the S at ~ 8.0 mph)
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Quoting Levi32:


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


Thanks again...
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I am not seeing any impressive winds or pressure from recon
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Time: 16:33:00Z
Coordinates: 13.3667N 73.9W
Acft. Static Air Press: 842.0 mb (~ 24.86 inHg)
Acft. Geopotential Hgt: 1,577 meters (~ 5,174 feet)
Extrap. Sfc. Press: 1007.3 mb (~ 29.75 inHg)
D-value: -
Flt. Lvl. Wind (30s): From 185° at 7 knots (From the S at ~ 8.0 mph)
Air Temp: 21.7°C (~ 71.1°F)
Dew Pt: 5.8°C (~ 42.4°F)
Peak (10s) Flt. Lvl. Wind: 9 knots (~ 10.3 mph)
SFMR Peak (10s) Sfc. Wind: 25 knots (~ 28.7

lowest pressure so far, looks like the coc might be even further south and west than previously thought
Member Since: April 29, 2007 Posts: 0 Comments: 7631
Quoting sunlinepr:


Thanks Levi, for your analisys... What about that wave in mid. Atl???


Something to watch for later, but not a major concern right now.
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21L/TS/T/CX
mark
14.13N/73.63W
Member Since: July 15, 2006 Posts: 168 Comments: 53285
Quoting Levi32:
Good morning all.

Tropical Tidbit for Tuesday, November 2nd, with Video; The latest on Tomas


Thanks Levi, for your analisys... What about that wave in mid. Atl???
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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.
your island could be in for some heavy rain too be safe
Member Since: September 11, 2010 Posts: 1 Comments: 4266
In the aftermath of tropical storm tomas 2 people died on Curacao. I wonder why there was no tropical storm warning because they got tropical storm winds annyway....

Large parts of Curacao are underwater
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How much does walmart make annually?
Wal-Mart said net income in Q1 '08 rose to $4.096 billion.

Haiti's GNP for 2005 was 3.88 billion... Now it's quite lower....

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If Tomas stalls off Haiti as a strong Hurricane that nation will exist no more. It will be wiped from the globe. Truly a worst case scenario. Maybe it will continue West and curve later. Doesn't look like it though.

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Stalling near any of the Greater Antilles will create a potential flooding nightmare for those islands reguardless of actual intensity at or near landfall.....Tomas is not done yet after the damage in the Lesser Antilles.....This could be, and already has been, a really bad situation for the Antilles in a year of relative calm in spite of the numbers.
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Member Since: July 15, 2006 Posts: 168 Comments: 53285
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.
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Quoting stormpetrol:


In my estimation about 130-160 miles NE of coc with roughly 43 mph winds.


As of 11:00 AM
ESTIMATED MINIMUM CENTRAL PRESSURE 1003 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT.......100NE 40SE 0SW 30NW.12 FT SEAS..180NE 60SE 60SW 210NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

Hmmmm, still 4 1/2 hours till next advisory. Tell me what you think it will be at 5PM?

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70. Skyepony (Mod)
Atleast the doomsday NOGAPS hasn't done too well with Tomas.. (error each day)

NGPS CONSTANT 112.4 174 215 213.5 336.9

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Member Since: July 15, 2006 Posts: 168 Comments: 53285
What Ridge is going to deviate Tomas N?? Seems like he's open to the W, for the moment....


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Quoting Inactivity:


How strong winds are they reporting? and how close to the CoC were they with that Report?


In my estimation about 130-160 miles NE of coc with roughly 43 mph winds.
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Quoting Neapolitan:

Don't know that I'm being fatalistic; realistic seems more like it, given the current forecasts. But realism and optimism aren't mutually incompatible; I--sadly, hesitatingly--accept the former, while stubbornly clinging to the latter.


Wasn't referring to anyone in particular.

But, my main point is that forecasts can and are wrong all the time. Predicting the future is never "realistic," especially the farther out you go.

We're talking about a forecast over 3 days out. By no means set in stone.

Also, it was just a suggestion and IMO, as I stated. I, personally, will have no angst until Thursday and may not have to have any at all. :)
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Quoting JRRP:

mmmm could be
Link


I'd say your right, but that is in the upper levels too, not sure if his the lower level circulation is vertically stacked with his upper level? Any one have any data to show how stacked he is right now?
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X
Member Since: July 15, 2006 Posts: 168 Comments: 53285
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Huge squall line gonna be heading for Florda and all this will merge and influence Tomas into one hellava rain maker somewhere in the ocean or Haiti/Dominican Republic
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Quoting reedzone:
RECON should find winds of 60+ mph. I believe Tomas will restrengthen into a Hurricane tonight, probably around midnight.


Every report of strengthening over the next 36 hours could determine its fate.At that rate it will be a hurricane by 11PM, a touch closer to the worst case senario.BAD NEWS:(
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Quoting reedzone:
RECON should find winds of 60+ mph. I believe Tomas will restrengthen into a Hurricane tonight, probably around midnight.
after sunset that process will or should begin convective cycle number 6 as i keep track
Member Since: July 15, 2006 Posts: 168 Comments: 53285

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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.