Unprecedented Hurricane Tomas pounding the Lesser Antilles

By: Dr. Jeff Masters , 3:38 PM GMT on October 30, 2010

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Hurricane Tomas, an unprecedented Lesser Antilles hurricane for so late in the season, is bearing down on the islands of St. Lucia and St. Vincent with Category 1 winds of 75 mph. Recent radar imagery from the Martinique radar shows that Tomas is still in the organizing stage, with an eyewall that just closed off, and a weak area of echoes on the south side, due to modest wind shear of 10 knots caused by southerly upper-level winds. The Hurricane Hunters reported top surface winds in the northern eyewall near 75 mph. St.Lucia figures to get the worst blow from Tomas, as this island will experience the strong right-front quadrant of the storm--the north eyewall. Winds on the island were sustained at 46 mph, gusting to 67 mph, at 11am EDT. Winds at Barbados peaked at 37 mph, gusting to 56 mph, early this morning, and the pressure bottomed out at 994 mb. Satellite loops of Tomas show a large and well-organized Cape Verdes-type hurricane, with good upper level outflow on all sides except the south, and an impressive amount of heavy thunderstorm activity. This is a very dangerous hurricane that is just beginning to get going. You can follow the progress of Tomas through the islands today with our wundermap zoomed in on St. Lucia.


Figure 1. Morning radar image from the Martinique radar shows the eye of Tomas moving between the islands of St, Lucia to the north and St. Vincent and the Grenadines to the south. The southern portion of the eyewall had just closed off with this image. Image credit: Meteo France.

Intensity forecast for Tomas
Now that the eyewall of Tomas has completely closed off, a period of steady and possibly rapid intensification lasting until Sunday afternoon is likely. The intensification rate may then be slowed by an increasing flow of southwesterly upper-level winds, which are expected to bring dry air and a moderate 15 - 20 knots of wind shear to Tomas Sunday through Tuesday, according to the latest SHIPS model forecast. Shear is then expected to relent, allowing more intensification on Wednesday. Water temperatures are a record warm 29.5°C and the Tropical Cyclone Heat Potential--a measure of the total heat content of the ocean--is a very high 100 kJ/cm^2, which is very favorable for rapid intensification. I expect the Tomas will strengthen to a Category 3 or 4 hurricane by Wednesday.


Figure 2. Hurricane specialists Robbie Berg (background) and Dan Brown (foreground) discuss the latest data on Tomas last night at the National Hurricane Center.

Track forecast for Tomas
The computer models have come into better agreement this morning that after Tomas reaches the central Caribbean 4 - 5 days from now, a turn to the north or northeast is likely, in response to a strong trough of low pressure expected to develop over the Eastern U.S. The exact timing of this turn to the north or northeast is difficult to predict at this time, as steering currents will be weak in the Caribbean after Tomas passes through the Lesser Antilles today and Sunday. At this time, is appears that the Dominican Republic and Haiti are most at risk from a strike by Tomas, though the storm could move as far west as Jamaica, or as far east as the northern Lesser Antilles Islands.


Figure 3. Hurricane specialist Dan Brown computes Tomas' radius of tropical storm force winds using the old-fashioned paper track plot and dividers technique. Hurricane specialists at NHC commonly use a paper track plot to mark all storm center fixes and compute the current motion of the storm. A storm's current heading and speed in NHC advisories is usually a 12-hour average of the motion up until the final fix position.

Tomas, Shary, and the 2010 hurricane season in perspective
Tomas' formation ties 2010 with 1995 and 1887 for 3rd place for most number of named storms in an Atlantic hurricane season. Only 2005 (28 named storms) and 1933 (21 named storms) were busier. Atlantic hurricane records go back to 1851, though there were likely many missed named storms prior to the beginning of satellite coverage in the mid-1960s. The intensification of Shary and Tomas into hurricanes today brings the total number of hurricanes this season to twelve, tying 2010 with 1969 and 1887 for second place for most hurricanes in a season. The record is held by 2005 with fifteen hurricanes, and I don't think we'll beat that record this year!

The formation of Tomas so far south and east this late in the season is unprecedented in the historical record; no named storm has ever been present east of the Lesser Antilles (61.5°W) and south of 12°N latitude so late in the year. Hurricane Six of 1896 came close--it was also a tropical storm south of 12°N and east of 61.5°W on October 29, but nine hours earlier in the day. That storm recurved to the north and missed the Lesser Antilles. Tomas' track through the southern Lesser Antilles so late in the year is unprecedented. There have been only two other tropical storms that formed after October 15 south of 12°N and east of 61.5°W: Hurricane Jose, which was a tropical storm in that region on October 18, 1999, and Tropical Storm Nicolas, on October 16, 2003. Tomas most reminds me of a storm I flew into with the Hurricane Hunters--Hurricane Joan of 1988, which was a tropical storm on October 14 near Tomas' current location, and later strengthened into a Category 4 hurricane that hit Nicaragua. According to Chenoweth (2008), Tomas is the first tropical storm to cross through the Lesser Antilles Islands south of 16°N this late in the year since 1724. In that year, a tropical storm on 12 November crossed the islands at 13.7°N 61.5°W, and later became a hurricane that affected Jamaica. There was also a hurricane on 30 October 1671 that crossed 61.5°W at 13.3°N, and did damage on Barbados.

Another unusual aspect of Tomas' formation is that we now have two simultaneous hurricanes in the Atlantic Ocean on October 30. There has been only one hurricane season since 1851 that had had two simultaneous hurricanes later in the year--1932, when Hurricane Ten and Hurricane Eleven both existed November 7 - 10. Today is also the 5th latest date in the season that there have been two simultaneous named storms in the Atlantic. The record was set way back in 1887, when Hurricane Eighteen and Tropical Storm Nineteen were both active on December 8. There were three years that had simultaneous November named storms: 1932, 1961, and 2001.

References
Chenoweth, M. and D. Divine (2008), "A document-based 318-year record of tropical cyclones in the Lesser Antilles, 1690-2007", Geochemistry, Geophysics, Geosystems, 9, doi:10.1029/2008GC002066.

Next update
I'll have more on Sunday by 3pm EDT. I'm headed home to Michigan today, after a very valuable week here at the National Hurricane Center. The experience gave me a new appreciatation for just how good the forecasters are at what they do. NHC's hurricane experts are truly world-class, and we are very fortunate to have such a talented group of hard-working forecasters keeping us informed on the dangers we face from Atlantic hurricanes.

Jeff Masters

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at least 1 of the BAMM models take Tomas into rode island thats scary because if that plays out remember Hazels track i hope it doesnt pull that eek
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842. JLPR2
Tomas is moving a little to the NW now, probably a wobble.

I have seen it today being: stationary - west - stationary - NW.

Steering currents seem to be weak but movement to the west should continue soon.
Link
Member Since: September 4, 2007 Posts: 7 Comments: 8690
841. Gorty
Quoting Tazmanian:
olny if TD 2 and TD 5 where name storms


oh well


I know right!! But like you said, oh well.
Member Since: November 8, 2008 Posts: 12 Comments: 1058
RI/21L/H/T/C2
MARK
13.79n/62.33w


Member Since: July 15, 2006 Posts: 171 Comments: 53787
olny if TD 2 and TD 5 where name storms


oh well
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Quoting kmanhurricaneman:
TOMAS is gonna explode tonight cat 3 for sure


wouldnt doubt it
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837. JRRP
Quoting largeeyes:
Important to remember that Dean passed north of St. Lucia, while Tomas is south. Thus, of course those in the south will think Tomas is much worse than Dean was.

Dean was in Aug
Tomas is in Nov
Member Since: August 16, 2007 Posts: 0 Comments: 5790
Quoting TORMENTOSO83:

I think that Tomas is gonna do the same thing that Hurricane Hortense did back in 1996, she stayed almos stationary and the moved NW impacting the southwesst croner of PR!!!

One question!!... When a cyclone is slowing down it movement, is because, besides is it intensifying, is gonna make a drastic move toward the trof?
usually means it is intensifying
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Quoting JRRP:

a bit south but still showing over Hispaniola

I think that Tomas is gonna do the same thing that Hurricane Hortense did back in 1996, she stayed almos stationary and the moved NW impacting the southwesst croner of PR!!!

One question!!... When a cyclone is slowing down it movement, is because, besides is it intensifying, is gonna make a drastic move toward the trof?
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Important to remember that Dean passed north of St. Lucia, while Tomas is south. Thus, of course those in the south will think Tomas is much worse than Dean was.
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832. Gorty
The intensity models are doing an absolutely terrible job with Tomas.
Member Since: November 8, 2008 Posts: 12 Comments: 1058
Tomas looks to be moving right along at the speed(15-20k) and on the track forecast by NHC. Looks to be srengthening as well, again as forecast. Wouldn't be surprised to see a ramp-up a category over what's forecast tonite...though they do speak to good chance of RI. Could see 100k easily within 24 hours.
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Quoting Xandtar:
Here on the west coast of Dominica the mid-afternoon was the worst, with power out for several hours and gusts around 60 mph or so (no wind gauge).

Things got a little better for a couple of hours but the wind has picked up again, it's going to be a long night, go away Tomas!
Be safe. Stay inside until the all clear is given.
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Quoting stormwatcherCI:
Ok, thanks.


No sweat. I have struggled with the various options. I hope we can all benefit, through our collective experience.

Cheers!
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828. JLPR2
Quoting Relix:
I have a very relaxed attitude here in PR. Pretty sure this will barely amount to a few showers.


Was raining a little while ago. XD
Member Since: September 4, 2007 Posts: 7 Comments: 8690
827. JLPR2
Quoting Tazmanian:



when we see the neame next time we may have a new name and it wont be Tomas the next time a round when we have this storm name Tomas


ah! Yep, I agree.
Member Since: September 4, 2007 Posts: 7 Comments: 8690
826. Relix
I have a very relaxed attitude here in PR. Pretty sure this will barely amount to a few showers.
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Quoting CybrTeddy:


I think he's right. The islanders think this is much worse than Dean and Debbie ever were. Plus, there is a lot of damage being reported.
Quoting Tazmanian:



when we see the neame next time we may have a new name and it wont be Tomas the next time a round when we have this storm name Tomas
Quoting weatherlover94:


retire the name


Oh!

Sorry Taz, I had no clue what you were talking about for a second :P
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767 Bobbyweather [refering to comment762] "I believe you are wrong on the special advisory, which was issued 10pm UTC."
768 Tazmanian "well the new one now is 8pm"

Thanks. Didn't catch that #7 was a special: the 8pm was posted later than usual.
Corrected to #7A
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Here on the west coast of Dominica the mid-afternoon was the worst, with power out for several hours and gusts around 60 mph or so (no wind gauge).

Things got a little better for a couple of hours but the wind has picked up again, it's going to be a long night, go away Tomas!
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Quoting TropicalAnalystwx13:


??


retire the name
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Quoting CybrTeddy:


I think he's right. The islanders think this is much worse than Dean ever was. Plus, there is a lot of damage being reported.
How strong was Dean when he passed there ?
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Quoting mbjjm:

There were also many weather blogs especially crown weather which had been warning the Caribbean for the past two weeks.
Yes you have to be good because to predict a storm like this in such an unusual area this time of the year isn't easy, the western caribbean is climatology possible but not the eastern caribbean.
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Quoting TropicalAnalystwx13:


??



when we see the neame next time we may have a new name and it wont be Tomas the next time a round when we have this storm name Tomas
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Quoting TropicalAnalystwx13:


??


I think he's right. The islanders think this is much worse than Dean and Debbie ever were. Plus, there is a lot of damage being reported.
Member Since: July 8, 2005 Posts: 259 Comments: 24016
Quoting PSLFLCaneVet:


Good info. I would add one thing to your explanation. At times, one must select "copy image location", depending on the source of the picture/image.
Ok, thanks.
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Quoting Tazmanian:






eeeeek! we may not have tomas the next time a round


??
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814. JRRP
Quoting MiamiHurricanes09:
The 00z dynamical model envelop has come into better agreement. They show the poleward turn occurring a little earlier though...more towards 72W.


a bit south but still showing over Hispaniola
Member Since: August 16, 2007 Posts: 0 Comments: 5790
Quoting HurricaneDean07:
when will they be in Tomas?
0600 UTC/2a.m EDT.
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Quoting MiamiHurricanes09:
I agree. I think I'll just start sleeping now and wake up at 2a.m to see what they find, lol.
when will they be in Tomas?
Member Since: October 3, 2010 Posts: 40 Comments: 4129
Quoting MiamiHurricanes09:
The 00z dynamical model envelop has come into better agreement. They show the poleward turn occurring a little earlier though...more towards 72W.







eeeeek! we may not have tomas the next time a round
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Quoting stormwatcherCI:
I just right click on the image ,click on view image info.
When it comes up copy and then when you click on WU image button paste and post comment.


Good info. I would add one thing to your explanation. At times, one must select "copy image location" after the right click, rather than "copy image", depending upon the source of the picture/image.
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Thougts go out to those in st lucia looks like there taken as real battering right about now...
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The 00z dynamical model envelop has come into better agreement. They show the poleward turn occurring a little earlier though...more towards 72W.

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TOMAS is gonna explode tonight cat 3 for sure
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Quoting clwstmchasr:
I don't know if this has been said today or not but kudos to Levi for predicting Tomas a week ago. He said that the SE Caribbean was primed for development and look what happened. The guy really knows his tropical weather.
I agree 100 %. Especially for one so young.
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7:30 pm in St. Lucia...

http://stormcarib.com/reports/current/report.php?id=1288484648_66493

Published: Sat, Oct 30 20:24 EDT
By "Christopher Kessell"
Hell! When is Tomas' wrath going to let up???!!



This is way worse than Dean (although for us up north it was windier but I guess not for those in the south) and has much stronger winds than we had with Debbie... So take those two and add them together and you have Tomas!



I had to go back down to Castries at 5:30 pm, what a nightmare that was. Managed to get some diesel from a friend but had to do it in the pissing rain with howling wind gusts; not pleasant at all. The main highway was still passable but there were a few areas where the water was flowing swiftly across the road but not dangerous at that time. However it was black like the inside of a cow and very difficult to see the edge of the road, I kept questioning my sanity the entire way down...



So after filling up the tank it was time to head back.... Jesus! Things were much worse and the road at Choc was almost impassable. I was driving a SUV and it started drifting sideways and kept having to head into the stream to get through. Very nasty and I was incredibly relieved to get through.



The worst to report is that the one and only bridge over the Choc river is being undercut by the river. The Southbound lane has settled at least 6" on that side and I would not be surprised if it collapses by morning....



Without that vital bridge, traffic between the north and south will have to go several miles inland and wind along a narrow and hilly secondary road.... Oh Joy!!! :-(



Power is almost certainly out island wide and only those of use with generators and businesses will have some semblance of normalcy tonight. Thankfully Lime internet is still up and running! Getting power back up will be a pain I am sure as there are a lot of trees and other debris over the lines and I guess in the south there will be poles down as well. Did not see any of that up here in the north.



Well thats it for not, I will check in tomorrow morning if the net is working...



All the best,



Chris Kessell


Member Since: July 12, 2007 Posts: 0 Comments: 6032
Quoting CybrTeddy:
I think the next recon will easily find a 105-110 mph hurricane once it gets there..
I agree. I think I'll just start sleeping now and wake up at 2a.m to see what they find, lol.
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802. DDR
Hi SLU
You watching the radar?feeder bands here can sometimes get nasty
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Quoting scott39:
Why is the NHC so slow to move Tomas to the N?
It's not moving North!
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800. JLPR2
When are the hurricane hunters supposed to go into Tomas again?
Member Since: September 4, 2007 Posts: 7 Comments: 8690
I think the next recon will easily find a 105-110 mph hurricane once it gets there..
Member Since: July 8, 2005 Posts: 259 Comments: 24016
798. flsky
Quoting islander101010:
the storm is not affecting richard branson on his private islands benifit party with the victoria secret girls

Good fortune shines on this person constantly....
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Quoting MiamiHurricanes09:
Tomas maintains its strength.

AL, 21, 2010103100, , BEST, 0, 135N, 617W, 80, 982, HU


Note the coordinates, they're the same as the 8 pm. I think the NHC just updated the ATCF for the 80 knot winds that was given at 6.

The damage reports out of the islands sound pretty bad, venture to say Tomas is a Category 2.
Member Since: July 8, 2005 Posts: 259 Comments: 24016
796. DDR
Southern edge or feeder band is approaching Trinidad and Tobago,im expecting possible heavy rains/gusty winds from about midnight. Radar...Link
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795. SLU
Quoting Grenada:



What can anyone say, it is devastating in more ways than one, I remember every minute of Ivan. Our thoughts are with all on all the Islands that were hit.


Thank you. We may need external assistance to recover from this one based on what i'm hearing.

Quoting Stormchaser2007:

Where are these damage reports from?

I've only heard of some roof damage and minor structural damage in St. Lucia


Damage is really severe:

Many, many buildings have sustained damage, widespread power outages, fallen trees, landslides and major flooding is a real threat given the heavy rains in the last few hours. However, information coming out of St. Lucia is limited since all radio stations are down. I was able to talk to my brother via a fixed line connection for over 30 mins with no difficulty so that's a good sign but I could hear the fury of Tomas unravel in the background

Member Since: July 13, 2006 Posts: 12 Comments: 5111
Quoting KoritheMan:


Yeah, Levi's a guy I really respect.


His videos are very good, very informative.
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you too bro! going to jam tomorrow evening for business meeting monday and tuesday hope he stays at that slow speed.
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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.