Tomas significantly weaker; damage very heavy on St. Lucia and neighboring islands

By: Dr. Jeff Masters , 6:38 PM GMT on October 31, 2010

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Hurricane Tomas dealt a punishing blow to the Caribbean island of St. Lucia, with the neighboring islands of St. Vincent, Dominica, and Barbados also suffering heavy damage. St. Lucia received the full brunt of the northern eyewall of Tomas as it intensified into a Category 2 hurricane with 100 mph winds early this morning. The St. Lucia weather service reported that sustained winds of 90 - 95 mph affected the island. A state of emergency has been declared on the island, and there are island-wide power outages on both St. Lucia and Dominica. Heavy flooding affected St. Lucia, washing out many bridges, and the airport is closed due to flooding. Damage to structures is considerable, with many roofs gone, and damage reported to hospitals, schools, and businesses.


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

Tomas significantly weakens
An Air Force hurricane hunter aircraft arrived at Tomas at 2pm this afternoon, and found a much weaker storm. The 2pm EDT center fix found that the pressure has risen to 994 mb, and the strongest surface winds were barely Category 1 hurricane strength, 74 mph. The aircraft found the the eyewall had mostly collapsed. Satellite loops of Tomas also show a significant degradation in the appearance of the storm in recent hours. The storm is highly asymmetric with very little heavy thunderstorm activity or upper level outflow on the west side, and the hurricane has only one prominent spiral band, on the east side. Wind shear is a high 20 knots due to strong upper level west-southwest winds, and these winds are driving dry air at mid-levels of the atmosphere into Tomas' west side, as seen on water vapor satellite imagery.


Figure 2. MODIS satellite image of Tropical Storm Tomas taken at 10:30am EDT Saturday October 30, as the storm began lashing the Lesser Antilles. At the time, Tomas was a Category 1 hurricane with 75 mph winds. Image credit: NASA.

Track forecast for Tomas
The ridge of high pressure pushing Tomas to the west-northwest will weaken by Tuesday, as a trough of low pressure approaches the eastern U.S. and breaks down the ridge. This will result in Tomas slowing from its current 9 mph forward speed to 5 mph by Tuesday. By Thursday, the trough to Tomas' north should be able to pull the storm to the north. The exact timing and location of this turn is still very uncertain. The computer model solutions from the latest set of 8am EDT (12Z) runs include a strike on Haiti on Friday (GFS and GFDL models), a strike on the Dominican Republic on Friday (NOGAPS model), a strike on Haiti on Saturday (UKMET model), a strike on Jamaica and eastern Cuba on Thursday (Canadian), or a strike on Puerto Rico on Friday (HWRF).

Intensity forecast for Tomas
Wind shear is forecast to remain in the high range, 20 - 25 knots, through Monday night, then decline to the moderate range, 10 - 20 knots, for the remainder of the week. Tomas will struggle with the shear and the dry air to its west through Tuesday, and I expect it will weaken to a tropical storm tonight, and remain a tropical storm until Tuesday, when the shear finally relents. At that point, re-intensification is likely, though with the storm's inner core gone, I expect it will take Tomas two days before it can re-establish a complete eyewall. Hindering that process will be the slow motion of the storm, which will allow cooler waters from the depths upwell to the surface and cool the SSTs. Still, the waters are very warm in the Caribbean and these waters extend to great depth, so the upwelling cool water may not impede intensification as much as might ordinarily be expected. The intensity Tomas might have as landfall in Hispaniola or Jamaica is highly uncertain, and a strength anywhere between a tropical storm and Category 3 hurricane would not be surprising. The HWRF model predicts Tomas will be a borderline tropical storm/Category 1 hurricane on Friday, while the GFDL foresees Tomas will be a strengthening Category 3 hurricane as it bears down on Haiti Friday afternoon. I predict Tomas will have trouble reorganizing, and will be a strengthening Category 1 hurricane on Friday as it makes landfall in Haiti or the Dominican Republic.


Figure 3. Hurricane specialists Robbie Berg (background) and Dan Brown (foreground) discuss the latest data on Tomas Friday night at the National Hurricane Center.

Next update
I'll have an update Monday morning.

Jeff Masters

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Quoting Portlight:


relief workers are there to help....Why would they want to evacuate?! over1 million Haitians are living under bedsheets in makeshift camps....there will be plenty of wind damage


Well if they don't evacuate I hope they can find safe shelters for them. Tents are probably not a good place to be.
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It is getting stronger on each run. We'll have to wait and see if it does that in all 5 quadrants.

Member Since: July 17, 2009 Posts: 71 Comments: 25956
Quoting Grothar:


Hey, I keep coming back. It looks like he could be coming back a little right now.
Probably feasting on the warm water..Hope you are well Gro...I gots da flu.....
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Quoting stormwatcherCI:


I think he is tired of disrespect he is getting and is beginning to thumb his nose at people. LOL


I know just how he feels.
Member Since: July 17, 2009 Posts: 71 Comments: 25956
Quoting Neapolitan:

The term hailwhen applied to graupel is erroneous. In fact, graupel is to hail what dust devils are to tornadoes: that is, two weather phenomena that look somewhat similar and are often confused with one another by the uneducated, yet are actually caused by quite different processes.


I'm well aware of that, just repeating what Wikipedia said. It's commonly confused with hail, thus what is listed as other terms. I do know it stings like a #$!#@ if its windy.

It's actually build up around a normal snowflake....
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Quoting stormwatcherCI:


I think he is tired of disrespect he is getting and is beginning to thumb his nose at people. LOL
Well I must say, If the storm stays like it is, we may see a much better outcome from this thing than originally feared...I cheer for shear....:)
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Quoting hydrus:
Last time I saw this thing it was on the verge of being a cat-3, now I can barely find it..Maybe it needs Geritol.?


Hey, I keep coming back. It looks like he could be coming back a little right now.
Member Since: July 17, 2009 Posts: 71 Comments: 25956
Quoting BahaHurican:
I'd be more interested in plans to minimize loss of life amongst those stranded in the tent camps. Best case would be to take the tents down until the storm has passed, but that would involve finding a place for people to take refuge from the rain; this, of course is why they need tents in the first place...
It is sadly a no win situation.
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Quoting BahaHurican:
I'd be more interested in plans to minimize loss of life amongst those stranded in the tent camps. Best case would be to take the tents down until the storm has passed, but that would involve finding a place for people to take refuge from the rain; this, of course is why they need tents in the first place...


under the right conditions a 'cane could cause carnage equal to or greater than the quake
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Quoting Grothar:


Looks a little better. (See post #150)


I think he is tired of disrespect he is getting and is beginning to thumb his nose at people. LOL
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I'd be more interested in plans to minimize loss of life amongst those stranded in the tent camps. Best case would be to take the tents down until the storm has passed, but that would involve finding a place for people to take refuge from the rain; this, of course is why they need tents in the first place...
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Quoting A4Guy:
is the trough really going to be deep and south enough to pull Tomas
all the way N and then NE?  Can a ridge build back in an push him
Westward again until the next trough pulls him out completely?  Just
seems like the storm is very deep in the tropics to be pulled so
dramatically...especially if he is not as strong as originally expected.

not casting..just asking


HPC seems to agree w/NHC:

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TropicalStormTomas's heading turned to dueWest
TS.Tomas's average speed moving between its last 2 reported positions increased to ~15.7mph(~25.2km/h) from its previous travel speed of ~14.3mph(~23.1km/h)
HurricaneTomas
31Oct 12amGMT - 13.5n61.7w - - 90mph_(~144.9km/h) - 982mb - NHC.Adv.#7A
31Oct 03amGMT - 13.6n62.1w - - 90mph_(~144.9km/h) - 982mb - NHC.Adv.#8
Category2
31Oct 06amGMT - 13.8n62.4w - 100mph_(~160.9km/h) - 982mb - NHC.Adv.#8A
31Oct 09amGMT - 14.0n62.9w - 100mph_(~160.9km/h) - 983mb - NHC.Adv.#9
31Oct 12pmGMT - 14.0n63.3w - 100mph_(~160.9km/h) - 983mb - NHC.Adv.#9A
Cat.1
31Oct 03pmGMT - 14.0n63.7w - - 90mph_(~144.9km/h) - 986mb - NHC.Adv.#10
31Oct 06pmGMT - 14.2n64.3w - - 70knots.(~129.6km/h) - 992mb - ATCF
31Oct 09pmGMT - 14.4n64.9w - - 75mph_(~120.7km/h) - 994mb - NHC.Adv.#11
TS.Tomas
1Nov. 12amGMT - 14.4n65.6w - - 55knots.(~101.9km/h) - 997mb - ATCF

Copy&paste 13.5n61.7w, 13.6n62.1w, 13.8n62.4w, 14.0n62.9w, 14.0n63.3w-14.0n63.7w, 14.0n63.7w-14.2n64.3w, 14.2n64.3w-14.4n64.9w, 14.4n64.9w-14.4n65.6w, pap into the GreatCircleMapper for a look at the headings and the distances traveled over the last 12^hours.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
Quoting CaneWarning:
Does anyone know if there is any organized effort to evacuate Americans and relief workers from Haiti? I sure hope they get them out of there. This could be bad. At least there shouldn't be much wind damage from this storm since most buildings left standing from the earthquake must be very sturdy.


relief workers are there to help....Why would they want to evacuate?! over1 million Haitians are living under bedsheets in makeshift camps....there will be plenty of wind damage
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275. KBH
Given how Tomas suddenly developed, does anyone have any info on that blob at 45 W?
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Does anyone know if there is any organized effort to evacuate Americans and relief workers from Haiti? I sure hope they get them out of there. This could be bad. At least there shouldn't be much wind damage from this storm since most buildings left standing from the earthquake must be very sturdy.
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Quoting Grothar:
Looking a little better on each frame. Will be intersting to see what it does in the next 24 hours. Wonder if there is any graupel in there?

Last time I saw this thing it was on the verge of being a cat-3, now I can barely find it..Maybe it needs Geritol.?
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Quoting GeoffreyWPB:


Looks a little better. (See post #150)
Member Since: July 17, 2009 Posts: 71 Comments: 25956
271. A4Guy
is the trough really going to be deep and south enough to pull Tomas
all the way N and then NE?  Can a ridge build back in an push him
Westward again until the next trough pulls him out completely?  Just
seems like the storm is very deep in the tropics to be pulled so
dramatically...especially if he is not as strong as originally expected.

not casting..just asking
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Looking a little better on each frame. Will be intersting to see what it does in the next 24 hours. Wonder if there is any graupel in there?

Member Since: July 17, 2009 Posts: 71 Comments: 25956
then there will be a cat 2 over Haiti.


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Happy Birthday Chicklit!!!!!
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Member Since: September 10, 2007 Posts: 0 Comments: 11097
Firing up on the western quadrant again.

Member Since: July 17, 2009 Posts: 71 Comments: 25956
Quoting Grothar:


Not a good scenario, Chicklit. Hope they are wrong.


and what if they're not?

falling out.
night everyone.
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Quoting Chicklit:


Not a good scenario, Chicklit. Hope they are wrong.
Member Since: July 17, 2009 Posts: 71 Comments: 25956
CAT2 over Haiti right now
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Quoting MiamiHurricanes09:
On the other hand, Anggrek is undergoing rapid intensification with one of the most impressive CDO's I've ever seen take shape. Check out the amount of -80C cloud tops surrounding the rapidly developing eye.



Go look at post #190!!! First my globes,now you're stealing my storms. LOL
Member Since: July 17, 2009 Posts: 71 Comments: 25956
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Quoting Neapolitan:
ATCF says Tomas is down to a 55 knot/997mb TS:

AL, 21, 2010110100, , BEST, 0, 144N, 656W, 55, 997, TS, 50, NEQ, 45, 45, 0, 45, 1010, 150, 30, 0, 0, L, 0, , 0, 0, TOMAS, M,
Which was expected per the 5 pm discussion.

SOME ADDITIONAL WEAKENING SEEMS LIKELY DURING THE NEXT DAY OR TWO AS
SOUTHWESTERLY SHEAR OF 20-25 KT AND SOME MID-LEVEL DRY AIR CONTINUE
TO IMPACT THE CYCLONE. THE OFFICIAL FORECAST FOLLOWS THE TREND IN
THE GUIDANCE AND IS ONCE AGAIN ADJUSTED DOWNWARD...BRINGING TOMAS
BELOW HURRICANE STRENGTH WITHIN THE NEXT 12 HOURS.
BEYOND A COUPLE
OF DAYS...THE SHEAR IS EXPECTED TO LESSEN WHILE TOMAS REMAINS OVER
FAVORABLE OCEANIC CONDITIONS. ALL OF THE INTENSITY MODELS RESPOND
AND SHOW THE SYSTEM INTENSIFYING IN THE 3 TO 5 DAY RANGE...
AND THE
OFFICIAL FORECAST FOLLOWS SUIT AND IS AT THE HIGH END OF THE
GUIDANCE THROUGHOUT THE FORECAST PERIOD.
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Quoting Neapolitan:

Ha! I thought they might share a common ancestry, but no: grapple is from the Middle English for a grappling hook (which name itself comes from grape), while graupel is from the German diminutive of graupe, or hulled grain.

Just thought you might want to know. ;-)


Yes, I do! LOL
Member Since: July 17, 2009 Posts: 71 Comments: 25956
Intensity forecast for Tomas

Wind shear is forecast to remain in the high range, 20 - 25 knots, through Monday night, then decline to the moderate range, 10 - 20 knots, for the remainder of the week.

Tomas will struggle with the shear and the dry air to its west through Tuesday, and I expect it will weaken to a tropical storm tonight, and remain a tropical storm until Tuesday, when the shear finally relents.

At that point, re-intensification is likely, though with the storm's inner core gone, I expect it will take Tomas two days before it can re-establish a complete eyewall.

Hindering that process will be the slow motion of the storm, which will allow cooler waters from the depths upwell to the surface and cool the SSTs.

Still, the waters are very warm in the Caribbean and these waters extend to great depth, so the upwelling cool water may not impede intensification as much as might ordinarily be expected.

Jeff Masters
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Quoting BahaHurican:
Can't believe I wasn't here for this little byplay... lol

A good teacher DOES correct in front of others, but only if that teacher makes it obvious that EVERYBODY was doing it wrong in the first place.... lol


Are you correcting me in front of others? LOL Actually, one can correct someone in the presence of others. It is just the manner in which one does it. For instance, we all got a very nice lesson on the meaning of graupel. Since it is a German word, we used in interchangeably for sleet and hail.
Member Since: July 17, 2009 Posts: 71 Comments: 25956
Quoting Grothar:


Bet you really had to grapple with that one.

Ha! I thought they might share a common ancestry, but no: grapple is from the Middle English for a grappling hook (which name itself comes from grape), while graupel is from the German diminutive of graupe, or hulled grain.

Just thought you might want to know. ;-)
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Quoting MiamiHurricanes09:
On the other hand, Anggrek is undergoing rapid intensification with one of the most impressive CDO's I've ever seen take shape. Check out the amount of -80C cloud tops surrounding the rapidly developing eye.

That's a WOWza.... I was saying earlier today that it was looking pretty good, but this is IMPRESSIVE.... would love to read what their mets are saying about it right now... Cocos are supposed to be in the path.
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that really cannot be the LLC racing off to the west..it is moving way way too fast for it to be that. It will be at 2pm tomorrows plots in an hour from now if that is indeed it.
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On the other hand, Anggrek is undergoing rapid intensification with one of the most impressive CDO's I've ever seen take shape. Check out the amount of -80C cloud tops surrounding the rapidly developing eye.

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Quoting Caribbeanislands101:
Tomas might be a remnant low tommorrow

That's possible, I suppose, but highly unlikely.
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Quoting Neapolitan:

The term hailwhen applied to graupel is erroneous. In fact, graupel is to hail what dust devils are to tornadoes: that is, two weather phenomena that look somewhat similar and are often confused with one another by the uneducated, yet are actually caused by quite different processes.


Bet you really had to grapple with that one.
Member Since: July 17, 2009 Posts: 71 Comments: 25956
Quoting Grothar:


There are many here. It is just that a good teacher doesn't correct someone in front of others. You can do that off-blog. (Which I enjoy doing, by the way) ha
Can't believe I wasn't here for this little byplay... lol

A good teacher DOES correct in front of others, but only if that teacher makes it obvious that EVERYBODY was doing it wrong in the first place.... lol
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Quoting alfabob:
Possible relocation to the SE.

i thouth of that, does any one know the chances of this happening?
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ATCF says Tomas is down to a 55 knot/997mb TS:

AL, 21, 2010110100, , BEST, 0, 144N, 656W, 55, 997, TS, 50, NEQ, 45, 45, 0, 45, 1010, 150, 30, 0, 0, L, 0, , 0, 0, TOMAS, M,
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Tomas is getting beat up pretty bad. Winds are probably near 50mph and displaced well to the west of the exposed circulation.

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Quoting JLPR2:


Yup, Tomas is going nude? What an indecent storm!
LOL!
Tomas might be a remnant low tommorrow
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Wow Tomas is such a dud in terms of the intensity he was supposed to have. This system was one of the most well organized tropical storms I have ever seen. Now it is one of the most disorganized hurricanes I have ever seen.

That being said, I feel for those in St Lucia and I hope all is ok there
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Member Since: May 16, 2009 Posts: 1 Comments: 1231
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 31 OCT 2010 Time : 231500 UTC
Lat : 14:30:15 N Lon : 65:18:15 W


CI# /Pressure/ Vmax
4.3 / 985.1mb/ 72.2kt


Final T# Adj T# Raw T#
3.6 3.3 3.1

Latitude bias adjustment to MSLP : +2.9mb

Center Temp : +3.6C Cloud Region Temp : -14.6C

Scene Type : SHEAR (0.22^ TO DG)
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Quoting largeeyes:
Graupel. Also known as small hail or soft hail or snow pellets.

The term hailwhen applied to graupel is erroneous. In fact, graupel is to hail what dust devils are to tornadoes: that is, two weather phenomena that look somewhat similar and are often confused with one another by the uneducated, yet are actually caused by quite different processes.
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240. JRRP
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the faint swirl at 15 N 65 W
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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.