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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the faint swirl at 15 N 65 W
Member Since: July 22, 2010 Posts: 0 Comments: 67
Quoting weatherwatcher12:

Most likely you are seeing the sheared convection which looks like movement.
Actually we have to worry about the convection since flooding is our major problem,
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What I should be watching then is the red-pink core, right?
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232.No relocation thats just convection center is on the points moving west
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235. JLPR2
Quoting Gearsts:
The center is actually moving west so anyone saying that is getting closer to pr look at the Shortwave (IR2)loop center is exposed and naked is speeding away from the convection.


Yup, Tomas is going nude? What an indecent storm!
LOL!
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Quoting alfabob:
Possible relocation to the SE.

That's what I said quite a while ago but no-one chimed in so I figured I was seeing wrong.
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Haiti update
Link
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231. IKE
Quoting Gearsts:
The center is actually moving west so anyone saying that is getting closer to pr look at the Shortwave (IR2)loop center is exposed and naked is speeding away from the convection.


That's what I see too...a naked swirl racing west. This ain't no hurricane anymore.
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Time to start handing out candy to the little neighbourhood heathens... brb soon, I hope.

Complete Update



AOI
AOI AOI AOI

AOI AOI AOI

TS BUSTED FORECAST ALIBI
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Member Since: August 2, 2010 Posts: 21 Comments: 9798
The center is actually moving west so anyone saying that is getting closer to pr look at the Shortwave (IR2)loop center is exposed and naked is speeding away from the convection.
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Uncertainty closer to PR

Member Since: August 2, 2010 Posts: 21 Comments: 9798
The Catl is getting more and more interesting....

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uncertain path



Member Since: August 2, 2010 Posts: 21 Comments: 9798
Graupel. Also known as small hail or soft hail or snow pellets.
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Quoting hurricaneeye:


It looks pretty close indeed.
I don't see it moving West!

Most likely you are seeing the sheared convection which looks like movement.
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Quoting TropicalAnalystwx13:


No...It doesn't hail when its near freezing...It sleets.


Isn't that Gropel? The little white pellets....
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Quoting stormpetrol:
I wouldn't rule out a PR threat just yet!! look at Tomas tonite!


It looks pretty close indeed.
I don't see it moving West!
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I wouldn't rule out a PR threat just yet!! look at Tomas tonite!
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Quoting TropicalAnalystwx13:


They aren't going to shift that far west, and in fact, most of them will probably only shift just a little bit.

If a model is calling for a Category 3 hurricane, its not going to shift much.

If a model is calling for a TS/C1, it should move considerably west, probably near Jamaica.

I'd expect a shift next time they come in, or later tonight.


This is not what I want to hear! :-(
I want it to eat dry air and die!
Member Since: August 17, 2008 Posts: 0 Comments: 672
Quoting Neapolitan:
Just looking back at the storms we've seen so far this year that have been downgraded before coming back, Phoenix-like:

1) Alex was a tropical storm for 20 hours before devolving into a tropical depression for 12 hours, after which the storm went on to become a tropical storm again, and then a hurricane.

2) Colin was a TS for just 12 hours before fading into nothingness for 48 hours, after which he grew back into a TS for several days.

3) Danielle was a hurricane for 24 hours--including six hours at Cat 2--before falling back into a tropical storm for six hours, after which she went on to become a hurricane for nearly a week, including 24 hours spent as a major storm.

4) Igor spent 30 hours as a tropical storm before becoming a tropical depression for 18 hours. After that, of course, he went on to become the most energetic storm of the year, spending 220 hours as a hurricane, 120 of those as a major hurricane.

5) Lisa was a tropical storm for 48 hours before turning into a TD for half a day. After that she went on to spend several days as both a hurricane and a tropical storm.

The situation for each of these storms was different, of course, but the bottom line is this: don't write off a storm--that is, don't let down your guard--simply because it's struggling at the moment--especially when all indications are that it'll be in a better neighborhood very shortly.

+100, Tomas have seen a better previous 2 days, but this is deceiving, of course Tomas could dissipate, but I doubt it very much, another 24 hours and we might just be saying WOW!!!
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215. bwi
Quoting UKHWatcher:


Can someone more informed than I tell the good people at GOES-13 that their longitudes have been wrong between 70 West and 50 West all day. I've been getting confused especially on the close up maps all day!


There's a contact link at the SSD website -- they've responded quickly in the past when I've mentioned stuff like this, although Sunday night maybe not...
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its forcast to be come a strong cat 2 by time land fall comes
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Quoting UKHWatcher:


Can someone more informed than I tell the good people at GOES-13 that their longitudes have been wrong between 70 West and 50 West all day. I've been getting confused especially on the close up maps all day!


It's 60, just poor resolution IMO. Note the circle at the top of the 8 is a bit larger than that of the 6.
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Quoting scott39:
Sometimes it feels like there is a teacher in the room correcting people!


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
Member Since: July 17, 2009 Posts: 71 Comments: 26010
Haiti and D.R. are very lucky that Tomas should only be a Cat 1.
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Quoting sunlinepr:


Can someone more informed than I tell the good people at GOES-13 that their longitudes have been wrong between 70 West and 50 West all day. I've been getting confused especially on the close up maps all day!
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Quoting TropicalAnalystwx13:


:P
Oh was I that obvious?
Member Since: June 13, 2009 Posts: 0 Comments: 6752
Quoting scott39:
Great song Grothar! My mom would play that for me when I was in her womb.


Go ahead, make me feel older than I am. Glad you enjoyed it (and more that you remembered it) LOL
Member Since: July 17, 2009 Posts: 71 Comments: 26010
Just looking back at the storms we've seen so far this year that have been downgraded before coming back, Phoenix-like:

1) Alex was a tropical storm for 20 hours before devolving into a tropical depression for 12 hours, after which the storm went on to become a tropical storm again, and then a hurricane.

2) Colin was a TS for just 12 hours before fading into nothingness for 48 hours, after which he grew back into a TS for several days.

3) Danielle was a hurricane for 24 hours--including six hours at Cat 2--before falling back into a tropical storm for six hours, after which she went on to become a hurricane for nearly a week, including 24 hours spent as a major storm.

4) Igor spent 30 hours as a tropical storm before becoming a tropical depression for 18 hours. After that, of course, he went on to become the most energetic storm of the year, spending 220 hours as a hurricane, 120 of those as a major hurricane.

5) Lisa was a tropical storm for 48 hours before turning into a TD for half a day. After that she went on to spend several days as both a hurricane and a tropical storm.

The situation for each of these storms was different, of course, but the bottom line is this: don't write off a storm--that is, don't let down your guard--simply because it's struggling at the moment--especially when all indications are that it'll be in a better neighborhood very shortly.
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Member Since: August 2, 2010 Posts: 21 Comments: 9798
Quoting Orcasystems:


It was the nicest thing I could think of to say. I was stuck between that and telling you to FOCUS, or just calling you an idiot... so I thought I did quite well.


That's not nice
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Quoting scott39:
Sometimes it feels like there is a teacher in the room correcting people!


:P
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http://www.ssd.noaa.gov/goes/flt/t2/flash-rb.html


not strengthening in the least
Member Since: July 22, 2010 Posts: 0 Comments: 67
Member Since: August 2, 2010 Posts: 21 Comments: 9798
Member Since: August 2, 2010 Posts: 21 Comments: 9798
199. JLPR2
Quoting TropicalAnalystwx13:


I believe its strengthening at this moment...


It needs a new eyewall, once conditions allow it it should start building it.
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Quoting BahaHurican:


Thanks Baha, I know our tropical connection well. It is from Jeanne that I learned you never know where it's headed till it is. You just have to watch closely.
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Still very disorganized though...

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I still think Tomas will hang on to hurricane status overnight. By tomorrow, the stress will be to great...

Well, I'm out for a short while. I gotta make a run or two before I get ready for work tomorrow. And this week is another 14-hour workday doozy... it's only Sunday, and just thinking about my schedule makes me wish it were Friday again... lol

l8r!
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What do you guys think about the BAMM solution? It would spare Haiti the center.
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Sometimes it feels like there is a teacher in the room correcting people!
Member Since: June 13, 2009 Posts: 0 Comments: 6752
Quoting JLPR2:


Sorry it that was an older pass :\
Now it says:
SPIRAL BANDING ON NORTH SIDE.


I believe its strengthening at this moment...
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Quoting TropicalAnalystwx13:
Tomas appears to be organizing again...
Looks like maybe he wants to relocate his coc to the se a little bit.
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191. JLPR2
Quoting TropicalAnalystwx13:


It said that at the 2PM pass this morning also.


Sorry it that was an older pass :\
Now it says:
SPIRAL BANDING ON NORTH SIDE.
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This Tropical Storm Anggrek,which I believe is a Southern Hemisphere storm. Not being picky, but shouldn't the icon showing on this website be reversed? They go in a clockwise motion.

Member Since: July 17, 2009 Posts: 71 Comments: 26010
Quoting JLPR2:
EYEWALL DISSIPATED.

Tropical Storm Tomas soon...


It said that at the 2PM pass this afternoon also.
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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.

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