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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893. Gorty
1:45 AM GMT on October 31, 2010
Dang, 31 friend requests at one time all from here!?! Thank you all!!
Member Since: November 8, 2008 Posts: 12 Comments: 1058
892. mbjjm
1:44 AM GMT on October 31, 2010
Quoting Cocotrini:
Can someone explain what is that weather as if its Tomas tail that is close to Trinidad and Tobago, is that something to be concerned about?


just a squall, a brief period of gusty winds and some rain as it moves through.
Member Since: August 23, 2010 Posts: 0 Comments: 310
891. emcf30
1:43 AM GMT on October 31, 2010
Quoting Chicklit:

That's not good.
You are saying they will retire Tomas?


If Tomas should follow the model package concensious with a Northward movement over Hati/Dominica Republic, the name would definatly be retired. There will sadly be lives lost if that senerio plays out. As we all know, thing can and will probally change, IMO
Member Since: August 7, 2010 Posts: 0 Comments: 1957
890. VAbeachhurricanes
1:43 AM GMT on October 31, 2010
Twin Russian eruptions, and Indonesian Eruptions, possibly effect climate?
Member Since: September 6, 2007 Posts: 0 Comments: 6704
889. CaribBoy
1:41 AM GMT on October 31, 2010
Quoting kimoskee:
Are the models shifting west?


no they are not
Member Since: October 6, 2007 Posts: 0 Comments: 6455
888. mbjjm
1:40 AM GMT on October 31, 2010
The models all seem to have Tomas inital intensity wrong could this affect the track? maybe landfall further east
Member Since: August 23, 2010 Posts: 0 Comments: 310
887. HurricaneDean07
1:40 AM GMT on October 31, 2010
Quoting troy1993:
Could someone please explain why despite the extremely active 2010 Atlantic Hurricane Season that virtually no storms have made landfall in the United States its like they have either gone into Mexico or out to sea. Is there something wrong the steering current system this year? And do you think that the 2011 Atlantic Hurricane Season will be more dangerous for the U.S?
This is because the La Nina Pumps up the troughs so it prevents storms from cape verde and the eastern caribbean to reach the us. and the ridge over the northern gulf takes anything from the southwestern atlantic into mexico and central america.
Member Since: October 3, 2010 Posts: 40 Comments: 4129
886. juniort
1:40 AM GMT on October 31, 2010
What about this heavy convection east of Barbados now?
Member Since: July 19, 2009 Posts: 0 Comments: 69
885. VAbeachhurricanes
1:39 AM GMT on October 31, 2010
Quoting GeoffreyWPB:





Bad BAMD Bad boy!
Member Since: September 6, 2007 Posts: 0 Comments: 6704
884. Tazmanian
1:39 AM GMT on October 31, 2010
where is Indonesia’s ???
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
883. Cocotrini
1:39 AM GMT on October 31, 2010
Can someone explain what is that weather as if its Tomas tail that is close to Trinidad and Tobago, is that something to be concerned about?
Member Since: October 29, 2010 Posts: 0 Comments: 6
882. kmanhurricaneman
1:38 AM GMT on October 31, 2010
Quoting DontAnnoyMe:


From NHC:

"For Atlantic hurricanes, there is actually one list for each of six years. In other words, one list is repeated every seventh year. The only time that there is a change is if a storm is so deadly or costly that the future use of its name on a different storm would be inappropriate for obvious reasons of sensitivity"

Usually deadly and costly go hand in hand, though, unfortunately.
exactly my point sorry i didnt explain in detail.
Member Since: August 14, 2008 Posts: 0 Comments: 1002
881. kmanhurricaneman
1:34 AM GMT on October 31, 2010
Quoting KEEPEROFTHEGATE:
how many you want 100,000 200,000 300,000 or more
???
Member Since: August 14, 2008 Posts: 0 Comments: 1002
880. DontAnnoyMe
1:34 AM GMT on October 31, 2010
Quoting kmanhurricaneman:
why did someone die from TOMAS?? that would be the only reason they would retire that name.


From NHC:

"For Atlantic hurricanes, there is actually one list for each of six years. In other words, one list is repeated every seventh year. The only time that there is a change is if a storm is so deadly or costly that the future use of its name on a different storm would be inappropriate for obvious reasons of sensitivity"

Usually deadly and costly go hand in hand, though, unfortunately.
Member Since: September 21, 2010 Posts: 1 Comments: 3690
879. kimoskee
1:33 AM GMT on October 31, 2010
Are the models shifting west?
Member Since: August 17, 2008 Posts: 0 Comments: 672
878. juniort
1:33 AM GMT on October 31, 2010
What about this heavy convection east of Barbados now?
Member Since: July 19, 2009 Posts: 0 Comments: 69
877. mbjjm
1:33 AM GMT on October 31, 2010

Tomas will likely be retired for the widespread damage across the Southern Windwards, there does not have to be a deth for a storm to be retired.

Hurricane names are retired by the World Meteorological Organization (WMO) in a meeting in March, April, or May of each year. Those hurricanes that have their names retired tend to be exceptionally destructive storms that often become household names in the regions they affected.

The process of retiring Atlantic hurricane names indefinitely officially began in 1969.

Prior to 1969, significant storm names were retired for ten years. Since 1953, an average of one storm name has been retired for each season, though many seasons (most recently 2009) have had no storm names retired, and after the 2005 season, five names were retired.

Storm names are retired following a request made at the spring WMO meeting by one or more of the countries affected by a hurricane.

2008
Gustav
Ike
Paloma

2007
Dean
Felix
Noel

2006
Nil

2005
Dennis
Katrina
Rita
Stan
Wilma

2004
Charley
Frances
Ivan
Jeanne

2003
Fabian
Isabel
Juan

Member Since: August 23, 2010 Posts: 0 Comments: 310
876. troy1993
1:32 AM GMT on October 31, 2010
Could someone please explain why despite the extremely active 2010 Atlantic Hurricane Season that virtually no storms have made landfall in the United States its like they have either gone into Mexico or out to sea. Is there something wrong the steering current system this year? And do you think that the 2011 Atlantic Hurricane Season will be more dangerous for the U.S?
Member Since: July 29, 2009 Posts: 0 Comments: 208
875. HurricaneDean07
1:32 AM GMT on October 31, 2010
Quoting Stormchaser2007:

very strong convection with this potent cat 1 hurricane
Member Since: October 3, 2010 Posts: 40 Comments: 4129
874. weatherwatcher12
1:32 AM GMT on October 31, 2010
Quoting GeoffreyWPB:



Why are the models exaggerating the northward turn so much?
Member Since: May 16, 2009 Posts: 1 Comments: 1231
873. KEEPEROFTHEGATE (Mod)
1:31 AM GMT on October 31, 2010
Quoting kmanhurricaneman:
why did someone die from TOMAS?? that would be the only reason they would retire that name.
how many you want 100,000 200,000 300,000 or more
Member Since: July 15, 2006 Posts: 178 Comments: 55984
872. kmanhurricaneman
1:30 AM GMT on October 31, 2010
oh look there is a pin hole eye !!!!!!!(snicker)
Member Since: August 14, 2008 Posts: 0 Comments: 1002
871. GeoffreyWPB
1:30 AM GMT on October 31, 2010
Quoting weatherlover94:
there is some model spread with Tomas this eve some are pointing more west than north


Member Since: September 10, 2007 Posts: 0 Comments: 11538
870. DontAnnoyMe
1:29 AM GMT on October 31, 2010
Quoting stormwatcherCI:
How strong was Dean when he passed there ?


According to the Wikipedia article, top winds were 80 mph. It may make sense that if Tomas passed to the south that there would be stronger winds - from the NE quadrant - vs. typically weaker winds from the NW quadrant.
Member Since: September 21, 2010 Posts: 1 Comments: 3690
869. Tazmanian
1:28 AM GMT on October 31, 2010
i wounder when dr m will do a blog on Merapi its a volcaneo thats makeing big news
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868. juniort
1:27 AM GMT on October 31, 2010
What about this heavy convection east of Barbados now?
Member Since: July 19, 2009 Posts: 0 Comments: 69
867. sunlinepr
1:27 AM GMT on October 31, 2010
Member Since: August 2, 2010 Posts: 21 Comments: 9882
866. Chicklit
1:27 AM GMT on October 31, 2010
Looks like this one has Hispaniola's name on it.
Member Since: July 11, 2006 Posts: 14 Comments: 11423
865. SLU
1:26 AM GMT on October 31, 2010
Quoting brohavwx:
Roof and Tree damage mostly but a lot more then anyone would have thought for a T.S.


I'm glad things have improved in Barbados but based on the destruction reported from St. Lucia, Barbados has been virtually spared.
Member Since: July 13, 2006 Posts: 13 Comments: 5367
864. kmanhurricaneman
1:24 AM GMT on October 31, 2010
Quoting Tazmanian:



may be
why did someone die from TOMAS?? that would be the only reason they would retire that name.
Member Since: August 14, 2008 Posts: 0 Comments: 1002
863. weatherlover94
1:24 AM GMT on October 31, 2010
there is some model spread with Tomas this eve some are pointing more west than north
Member Since: September 8, 2010 Posts: 0 Comments: 2231
862. geepy86
1:23 AM GMT on October 31, 2010
Hi taz.
Member Since: August 19, 2008 Posts: 0 Comments: 1704
861. sunlinepr
1:23 AM GMT on October 31, 2010


Member Since: August 2, 2010 Posts: 21 Comments: 9882
860. Tazmanian
1:22 AM GMT on October 31, 2010
Quoting Chicklit:

That's not good.
You are saying they will retire Tomas?



may be
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
859. TORMENTOSO83
1:22 AM GMT on October 31, 2010
Quoting JRRP:

could be
Thnx
Member Since: July 30, 2010 Posts: 0 Comments: 288
858. Chicklit
1:21 AM GMT on October 31, 2010
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

That's not good.
You are saying they will retire Tomas?
Member Since: July 11, 2006 Posts: 14 Comments: 11423
857. weatherlover94
1:21 AM GMT on October 31, 2010
who knows what Tomas may do next
Member Since: September 8, 2010 Posts: 0 Comments: 2231
856. SLU
1:20 AM GMT on October 31, 2010
Quoting stormwatcherCI:
How strong was Dean when he passed there ?


Dean had winds of 100mph when it passed St Lucia but ppl are saying that Tomas is much worse than Dean
Member Since: July 13, 2006 Posts: 13 Comments: 5367
854. brohavwx
1:19 AM GMT on October 31, 2010
Roof and Tree damage mostly but a lot more then anyone would have thought for a T.S.
Member Since: June 3, 2002 Posts: 0 Comments: 64
853. JRRP
1:15 AM GMT on October 31, 2010
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?

could be
Member Since: August 16, 2007 Posts: 0 Comments: 6213
852. SLU
1:15 AM GMT on October 31, 2010
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.


The same thought crossed my mind last night.

Dean was a "dry" hurricane for us with high wind damage and little rainfall and Tropical Storm Debby in 1994 was very, very wet and flooded out all low lying areas.

Therefore:

Dean + Debby = Tomas
Member Since: July 13, 2006 Posts: 13 Comments: 5367
851. brohavwx
1:15 AM GMT on October 31, 2010
Well, Barbados woke up to a nasty surprise this morning and it was only strong T.S. winds but higher gusts, but plenty of damage and hardly any preparation.

We're all just wondering what a Cat. 2 or 3 would do.
Member Since: June 3, 2002 Posts: 0 Comments: 64
pressure in Tomas 982 MB

http://tropicalatlantic.com/models/
Member Since: September 8, 2010 Posts: 0 Comments: 2231
we would be on W right now if TD 2 and TD 5 where name storms and if 92L 95L that was a long the gulf that went from 10% too 60% back too 10% and a few others
Member Since: May 21, 2006 Posts: 5091 Comments: 115454
848. KBH
Update from Barbados - strong winds subsiding in Barbados, still a few gusts and thunderstorms, storm warning discontinued, but a flood warning in force til 6.00am, flooding has increased in some areas, Electricity and water being restore...several roofs blown off and damage still being assessed...
Member Since: Posts: Comments:
Quoting CosmicEvents:
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.

The foward motion has slowed to under 7mph during the last two positions down from just over 10mph. I think your spot on everything else. Going to get very interesting.
Member Since: August 7, 2010 Posts: 0 Comments: 1957
845. SLU
Quoting DDR:
Hi SLU
You watching the radar?feeder bands here can sometimes get nasty


Yeh I realise there are some very heavy thunderstorms closeby. Looks like Trinidad might feel Tomas' wagging tail later on ...
Member Since: July 13, 2006 Posts: 13 Comments: 5367
Member Since: August 14, 2008 Posts: 0 Comments: 1002
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
Member Since: September 8, 2010 Posts: 0 Comments: 2231

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