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 pcola57:

Thanks sunlinepr, I'll work on that.."preciate it..
v/r
Moe


Enjoy it.... Anyone has any ideas or Met. links to share, I'm here to learn....
Member Since: August 2, 2010 Posts: 21 Comments: 9652
Quoting Grothar:


Looking better. Have one in color? They always look scarier
Keep specializes in scary! ;^)
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Quoting Orcasystems:


Stop it
is the wind and rain there yet
Member Since: July 15, 2006 Posts: 165 Comments: 52274
Quoting KEEPEROFTHEGATE:


I.T.C.Z. enhancement


Looking better. Have one in color? They always look scarier
Member Since: July 17, 2009 Posts: 63 Comments: 23727
Quoting sunlinepr:
Usually it is difficult to post animations. You need to access weather links where they are available in .gif format...

Use this link to create .gig animations and to plot them in this blog...

The link is:

http://www.nrlmry.navy.mil/htdocs_dyn_met/PUBLIC/nexsat/pages/NEXSAT.html

1. Select the area you want to animate..
2. In the Animate button select Gif89a
3. Select the size of the anim.
4. I usually select every 4th photo so that the resulting animation is not huge in size
5. Give time and when it is done copy and paste to the blog

Have fun with it....



Thanks sunlinepr, I'll work on that.."preciate it..
v/r
Moe
Member Since: Posts: Comments:
Keeper!..are you going to send me some snow this year?..pleazeeeeeee
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Quoting pcola57:

I agree..that said,all that energy's gotta go somewhere..
Yeah, Orca is Doom!
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Quoting PrivateIdaho:
It seems a little early in the year for such a vigorous low in the gulf of Alaska. Apparently a high is going to build in the western U.S. and keep it from coming on shore. Our extented is for clear skies and near record heat.

I agree..that said,all that energy's gotta go somewhere..
Member Since: Posts: Comments:
Usually it is difficult to post animations. You need to access weather links where they are available in .gif format...

Use this link to create .Gif animations and to plot them in this blog...

The link is:

http://www.nrlmry.navy.mil/htdocs_dyn_met/PUBLIC/nexsat/pages/NEXSAT.html

1. Select the area you want to animate..
2. In the Animate button select Gif89a
3. Select the size of the anim.
4. I usually select every 4th photo so that the resulting animation is not huge in size
5. Give time and when it is done, copy and paste to the blog

Have fun with it....


Member Since: August 2, 2010 Posts: 21 Comments: 9652
Quoting KEEPEROFTHEGATE:


winters coming


Stop it
Member Since: October 1, 2007 Posts: 81 Comments: 26493
Quoting Grothar:


You see it, too, huh?


I.T.C.Z. enhancement
Member Since: July 15, 2006 Posts: 165 Comments: 52274
Quoting pcola57:

Thanks Keeper..that's the one I was trying to Link..The entire Gulf of Alaska,Canada,and US West coast feeling it..
It seems a little early in the year for such a vigorous low in the gulf of Alaska. Apparently a high is going to build in the western U.S. and keep it from coming on shore. Our extented is for clear skies and near record heat.
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Quoting stoormfury:
aREA 11n 47W could be new invest 92L. TT is a vigorous spin with this area of increasing convection


You see it, too, huh?
Member Since: July 17, 2009 Posts: 63 Comments: 23727
Quoting KEEPEROFTHEGATE:


winters coming

Thanks Keeper..that's the one I was trying to Link..The entire Gulf of Alaska,Canada,and northern US West coast feeling it..
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Quoting JLPR2:


Good, it was a very nice day here, with lots of sun, yesterday I thought it would be all cloudy with creepy howling winds, thankfully Tomas fell apart.
How's everything going at your side of the world?


Torrential rains almost all day in Ft. Lauderdale. Don't know where it came from. Seemed to come in waves. My rain gauge showed 4.5 inches. Good excuse to stay in and watch football.
Member Since: July 17, 2009 Posts: 63 Comments: 23727
Member Since: August 2, 2010 Posts: 21 Comments: 9652
Quoting jurakantaino:
if you look at the Animation mosaique Antilles, it looks like a rotation to the south east of that convection, Any thoughts? the center is suppose to be south of PR not there...


The established center IS directly South of PR. However, over the past few hours there has been a trememdous flare-up of convection well to the East and South-east. I do not know if a new center could relocate, but unlikely at this time. It appears the center is far outracing the convection.
Member Since: July 17, 2009 Posts: 63 Comments: 23727
470. JLPR2
Quoting Grothar:


Same thing they told me about Tomas last week. How you doing JL?


Good, it was a very nice day here, with lots of sun, yesterday I thought it would be all cloudy with creepy howling winds, thankfully Tomas fell apart.
How's everything going at your side of the world?
Member Since: September 4, 2007 Posts: 7 Comments: 8459


winters coming
Member Since: July 15, 2006 Posts: 165 Comments: 52274
Member Since: August 2, 2010 Posts: 21 Comments: 9652
Quoting Grothar:
Impressive from what he looked just one hour ago.



Impressive flare up but looks like the low level center is almost at 67W already
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Quoting sunlinepr:
Thanks sunlinepr..
Tomas looks de-capitated..
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#456:
excellent graphic, thanks
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WU ensemble models...

Member Since: August 2, 2010 Posts: 21 Comments: 9652
Member Since: August 2, 2010 Posts: 21 Comments: 9652
Quoting KerryInNOLA:
Yea, he seems upset that it is a miss. Kinda sad.

Keeper. I just have about lost faith in intensity forecasts, that's all. It's not simple mindedness.
yes it is at the time up till 7 am this morning it looked like a bad one but things changed during the morning after sunrise and the effects pretty well done him in can things change again sure but hopefully not but if they do information has to be sent out no matter if it happens or not
Member Since: July 15, 2006 Posts: 165 Comments: 52274
Quoting JLPR2:


Some 850mb vort appeared, something is going on around there, but nothing to worry about at least for the moment.


Same thing they told me about Tomas last week. How you doing JL?
Member Since: July 17, 2009 Posts: 63 Comments: 23727
Quoting KerryInNOLA:
Saints crush overrated Steeler Dogs!

Good news for Caribbean as Dog Tomas weakens!
This is further proof that NHC and hurricane pundits in general don't have a clue when it comes to predicting intensities. NOT A CLUE!
It's you who doesn't have a clue. Last night, in the 11PM discussion, the NHC had this to say about intensity:
.
THERE CONTINUES TO BE LOW CONFIDENCE IN THE INTENSITY FORECAST.
NONE OF THE INTENSITY MODELS SHOW MUCH STRENGTHENING BEYOND ABOUT
90 KT. THE 200-MB FLOW OVER THE CARIBBEAN SEA SHOULD BE FAVORABLE
FOR STRENGTHENING...ESPECIALLY IF TOMAS MAINTAINS A MORE
SOUTHERN COURSE. HOWEVER...CROSS-SECTION ANALYSES OF THE GUIDANCE
DOES INDICATE THAT THE CYCLONE VORTEX COULD BECOME A LITTLE TILTED

OVER THE NEXT 48 HOURS OR SO...POSSIBLY DUE TO SHEAR BELOW THE
OUTFLOW LAYER. BECAUSE OF THESE MIXED SIGNALS...THE OFFICIAL
INTENSITY FORECAST ONLY SHOWS MODEST STRENGTHENING THROUGH 24 HOURS
AND ESSENTIALLY HOLDS THE INTENSITY FAIRLY STEADY THEREAFTER.
.
.
.
They also gave a decent percentage chance that the cyclone would be a TS right now. This isn't a video game or an exact science. It's a science of uncertainty.
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Quoting Grothar:
Impressive from what he looked just one hour ago.

Quoting Grothar:
Impressive from what he looked just one hour ago.

if you look at the Animation mosaique Antilles, it looks like a rotation to the south east of that convection, Any thoughts? the center is suppose to be south of PR not there...
Member Since: Posts: Comments:
458. JLPR2
Tomas almost to 67W at 14N, heading WSW.


Far away from the convection.
Member Since: September 4, 2007 Posts: 7 Comments: 8459
aREA 11n 47W could be new invest 92L. TT is a vigorous spin with this area of increasing convection
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Member Since: August 2, 2010 Posts: 21 Comments: 9652
Quoting Grothar:


Looks like a frozen Hurricane. Wonder what Levi has to say about this?

I dunno..just checking in here..but he's got a birds-eye view..this is one huge storm!!!
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Thomas could weaken below TS strenght or degenerate if the COC doesnt relocate under the convection
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453. JLPR2
Quoting Grothar:
Think this could be the next AOI?



Some 850mb vort appeared, something is going on around there, but nothing to worry about at least for the moment.
Member Since: September 4, 2007 Posts: 7 Comments: 8459
Quoting pcola57:
Try this one..
Gulf of Alaska
Link


Looks like a frozen Hurricane. Wonder what Levi has to say about this?
Member Since: July 17, 2009 Posts: 63 Comments: 23727
Report from bouy # 42059 (15.054 N 67.472 W):
Wind Direction (WDIR): ENE ( 70 deg true )
Wind Speed (WSPD): 25.3 kts
Wind Gust (GST): 31.1 kts
Wave Height (WVHT): 17.4 ft
Dominant Wave Period (DPD): 12 sec
Average Period (APD): 7.8 sec
Atmospheric Pressure (PRES): 29.87 in
Pressure Tendency (PTDY): +0.02 in ( Rising )
Air Temperature (ATMP): 84.0 °F
Water Temperature (WTMP): 84.6 °F
Dew Point (DEWP): 73.2 °F
Heat Index (HEAT): 90.5 °F
Member Since: Posts: Comments:
Try this one..
Gulf of Alaska
Massive storm

Link
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Impressive from what he looked just one hour ago.

Member Since: July 17, 2009 Posts: 63 Comments: 23727
g-nite
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Don't forget to click the Trop pts on top

Link
Member Since: July 17, 2009 Posts: 63 Comments: 23727
Quoting scott39:
I didnt know I was feeding one. All I feed is my dog and myself.


And I have a wonderful parrot. He is green and knows that his name is "Kiwi"

- take care and good eve.

check out his earlier posts if you dare.
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Goodnight
Member Since: June 13, 2009 Posts: 0 Comments: 6706
Member Since: August 2, 2010 Posts: 21 Comments: 9652
Didn't link right...sorry...
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Gulf Of AlaskaLink
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Quoting docrod:


Don't feed trolls
I didnt know I was feeding one. All I feed is my dog and myself.
Member Since: June 13, 2009 Posts: 0 Comments: 6706

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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.