Strengthening Tomas headed for the Lesser Antilles

By: Dr. Jeff Masters , 1:27 AM GMT on October 30, 2010

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Tropical Storm Tomas has exploded into existence in spectacular fashion, becoming the nineteenth named storm of this amazingly active 2010 Atlantic hurricane season. I'm reporting to you live from the National Hurricane Center tonight, where forecasters are working hard to stay abreast of Tomas' intensification. Three hurricane specialists are on duty tonight--Dave Roberts, who is handling Tropical Storm Shary, and Robbie Berg and Dan Brown, who are focusing on Tomas. The Hurricane Hunters have just left Tomas, as of 8pm EDT, and they found a significant increase in winds. Winds at their 1500 foot flight level were 70 mph, and surface winds as measured by the SFMR instrument were near 60 mph. This supports an increase in Tomas' winds to 60 mph in tonight's 8pm EDT public advisory. Since this is such a large increase in intensity from what was forecast--Tomas was not supposed to have 60 mph winds for another 24 hours--this necessitates issuance of a special advisory package. A full set of forecast maps, a marine advisory, wind probability forecast, and a discussion just went out to the world. While all this was occurring, several phone calls to Barbados, St. Lucia, and Martinique were made, alerting the islands to the fact that a Hurricane Warning may be required with the 11pm advisory tonight. NHC has both French speaking and Spanish speaking meteorologists on staff that can coordinate with the islands that don't have English as their main language. I listened in on a 5-minute conversation in French between the weather service in Martinique and NHC meteorologist Mike Tichacek, as they discussed when Martinique may want to issue a Hurricane Warning.


Figure 1. Warren VonWerne (right) of CARCAH presents the latest data from the Air Force Hurricane Hunters to hurricane specialist Robbie Berg.

Intensity forecast for Tomas
The forecasters at NHC are puzzling over the latest intensity forecasts for Tomas. The latest intensity forecast from the GFDL, HWRF, and SHIPS models are not that impressive, and they keep Tomas as a strong tropical storm or weak hurricane for the next five days. The wind shear forecast from SHIPS is particularly odd--the latest 18Z forecast predicts high wind shear of 20+ knots beginning Sunday morning, and the previous SHIPS forecast held wind shear below 15 knots for the next five days. The latest runs by the GFS, ECMWF, and UKMET models all show a very favorable environment for intensification over the next five days over the Caribbean, with Tomas positioning itself beneath an upper level high in a light wind shear environment. The best bet is that Tomas will intensify into a major hurricane over the Central Caribbean by early next week.


Figure 2. NHC meteorologist Mike Tichacek discusses the latest intensity forecast for Tomas with the Martinique weather service (in French.) In the background, hurricane specialist Dave Roberts works on advisories for Tropical Storm Shary.

Track forecast for Tomas
After Tomas reaches the central Caribbean 4 - 6 days from now, there are two possible track scenarios depicted by the models--a continued westerly motion towards Nicaragua, or a sharp turn to the north, with a track over Hispaniola or Puerto Rico. Steering currents will be weak, and we'll just have to wait and see how the steering currents evolve.

Tomas' formation location unprecedented this late in the season
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 formation of a tropical storm 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 (60°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 60°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 60°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 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.

Another unusual aspect of Tomas' formation is that we now have two simultaneous named storms in the Atlantic Ocean on October 29. There have been only four hurricane seasons since 1851 that have had two simultaneous named storms later in the year. 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.

Next update
I'll have more late Saturday morning.

Jeff Masters

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Quoting hydrus:
one of these troughs should lift Tomas out of the Caribbean. Which one i,m not sure.


I don't know which one... but I am sure tired of them running over my house to get there.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
Quoting hydrus:
Those are some ugly damn model runs...


That they are. And dynamic, don't forget dynamic. Seriously, I think it could be a serious situation for a lot of people. You know I NEVER make forecast, but at this point, I would not rule out a CAT 4, the way this is unfolding. "What a revoltin' development this is!"
Member Since: July 17, 2009 Posts: 71 Comments: 26522
FORECAST POSITIONS AND MAX WINDS

INITIAL 30/0300Z 12.2N 58.4W 55 KT
12HR VT 30/1200Z 13.0N 60.2W 65 KT
24HR VT 31/0000Z 13.7N 62.7W 75 KT
36HR VT 31/1200Z 14.2N 65.0W 85 KT
48HR VT 01/0000Z 14.5N 67.1W 90 KT
72HR VT 02/0000Z 15.0N 71.0W 95 KT
96HR VT 03/0000Z 15.5N 74.0W 100 KT
120HR VT 04/0000Z 16.0N 76.0W 100 KT

$$
FORECASTER BERG/BROWN
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Quoting ryang:
Heavy rain right here now. I expect the winds to gradually increase as time goes on

Keep in touch if you can.
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224. MZT
Quoting HurricaneDean07:
personally if this rapid intensification Continues/Gets going, i wouldnt be surprised to see a 105 MPH Cat 2 at 8 Am
Shoot it could just keep on intensifying beyond daybreak and be a CAT3 by the 11AM update. Who knows? The NHC is admitting in the tropical outlook that this is an unusual system.
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one of these troughs should lift Tomas out of the Caribbean. Which one i,m not sure.
Member Since: September 27, 2007 Posts: 1 Comments: 21430
this thing is undergoing RI and should be a hurricane soon
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Quoting TampaSpin:


Pottery i don't like the looks to this my friend. Someone is gonna get a really bad storm.

Well, there appears to be no way out, now.
All doors are slammed shut.......
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Quoting ryang:
Heavy rain right here now. I expect the winds to gradually increase as time goes on
Stay safe Ryang.

Hopefully you guys don't lose power.
Member Since: June 9, 2007 Posts: 4 Comments: 15921
219. Tabby
I wonder if they'll invite Dr. Masters back again.
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Quoting hydrus:
Those are some ugly damn model runs...

I have a Containerload of a Special Shower curtains available, for Florida residents only.
Interested?
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217. ryang
Heavy rain right here now. I expect the winds to gradually increase as time goes on
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Quoting pottery:

Nailed!


Pottery i don't like the looks to this my friend. Someone is gonna get a really bad storm.
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Quoting PSLFLCaneVet:


Hmmm. I don't think you should use "nice models" and "disturbing" in the same sentence. There might be a law. Greetings, Gro!


Boy, you can't say anything on this blog without getting ripped. LOL How you doing PSL?
Member Since: July 17, 2009 Posts: 71 Comments: 26522
Quoting cat5hurricane:

Me neither.
personally if this rapid intensification Continues/Gets going, i wouldnt be surprised to see a 105 MPH Cat 2 at 8 Am
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Member Since: September 27, 2007 Posts: 1 Comments: 21430
Quoting pottery:

Right here, in the panel on the left, this page.

I MEANT THE PANEL ON THE RIGHT.
sorry
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Quoting Grothar:


GFS models

Those are some ugly damn model runs...
Member Since: September 27, 2007 Posts: 1 Comments: 21430
210. KBH
Quoting Stormchaser2007:
Wouldn't be shocked if I wake up to a decent category 1 at 5am tomorrow.



Storm, hurricane warnins out already, so you need not wait till 5.00!
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Quoting BradentonBrew:


Is this available online or print media only? If so, can you attach a link


On the right hand side of this page is a section entitled: Recommended Links. Click on "Flying into Hurricane Hugo". You'll be ready to go. And a warm welcome to you!
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Quoting TampaSpin:
Posted this 2 days ago.....






Just had the wrong name attached to it tho....I had this one named Shary....LOL

Nailed!
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The usual garden variety thunderstorms over Central America.
Member Since: September 27, 2007 Posts: 1 Comments: 21430


GFS models

Member Since: July 17, 2009 Posts: 71 Comments: 26522
Quoting cat5hurricane:

Bring an umbrella & floating devise cuz you just never know ;)
My hat and my coolie cup..same difference..
Member Since: September 27, 2007 Posts: 1 Comments: 21430
Quoting BradentonBrew:


Is this available online or print media only? If so, can you attach a link

Right here, in the panel on the left, this page.

I MEANT THE PANEL ON THE RIGHT.
sorry
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Posted this 2 days ago.....






Just had the wrong name attached to it tho....I had this one named Shary....LOL
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Member Since: September 27, 2007 Posts: 1 Comments: 21430
Quoting PSLFLCaneVet:


For those who are new to the blog: the account of his experience with the HH's in Hugo is a must read. Time well spent.

Evening Pottery. Some wild happenings, eh?


Is this available online or print media only? If so, can you attach a link
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Link IVAAAN TRACK.....any similarities???
Member Since: August 14, 2008 Posts: 0 Comments: 1002
I wonder if they let Dr. Masters hit the "Send to the World" button on the 11PM discussion.
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Member Since: September 27, 2007 Posts: 1 Comments: 21430
Quoting cat5hurricane:

You'll be safe in Costa Rica. It's not heading your way.



REALLY?

If it takes the western path into Nicaragua, as is currently one of the solutions, it will.
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Quoting TropicalAnalystwx13:

Potentially dangerous track.
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Quoting brohavwx:
Further ... I cannot help but reflect on the poor guy who was put in charge of the NHC or whatever and tried to make a case for a QUIKSCAT replacement ... he was torpedoed out of office, BUT while argument was made against his position due to heavy Radar around the US and nearby, we out here still have to wait on (now) ASCAT - I understand that our local Doppler Radar funded by the EU is down at this time. I'll stop here as I don't want to be obscene ...

Understood...
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Quoting cat5hurricane:

You'll be safe in Costa Rica. It's not heading your way.
I have a business trip to Cabo San Lucas the middle of next week, will I be effected by the storm..?:)
Member Since: September 27, 2007 Posts: 1 Comments: 21430
Quoting Grothar:


That's nothing, PsychicMaria told me this 3 months ago. Nice models by the way and yes, disturbing.


Hmmm. I don't think you should use "nice models" and "disturbing" in the same sentence. There might be a law. Greetings, Gro!
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188. Relix
Well will go to bed relaxed. Doubt Tomas will amount to much except a few rains here in PR.
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Quoting cat5hurricane:

You'll be safe in Costa Rica. It's not heading your way.


OK, thanks
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Quoting pottery:

No.
Gradually "tilted" from the west coast upward to the east, Atlantic coast.
A couple hundred feet at most.
The east coast is generally rocky with cliffs and reefs.
The surf there is incredible on a CALM day.
Going to be awesome tonight and tomorrow..
Sounds about like Cayman then. Just wondered as I know when you have mountains the flooding is worse.
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Member Since: June 9, 2007 Posts: 4 Comments: 15921
Wouldn't be shocked if I wake up to a decent category 1 at 5am tomorrow.


Member Since: June 9, 2007 Posts: 4 Comments: 15921
THE GFS...ECMWF...AND GFDL ALL
SUPPORT A RELATIVELY STRONG MID-LEVEL RIDGE NORTH OF THE GREATER
ANTILLES AND SHOW TOMAS MOVING GENERALLY WESTWARD ACROSS THE
SOUTH-CENTRAL CARIBBEAN SEA. THESE ARE USUALLY THE MOST
TRUSTWORTHY OF THE DYNAMICAL MODELS...AND THE OFFICIAL FORECAST
FAVORS THEIR SCENARIO...LYING JUST TO THE SOUTH OF THE MODEL
CONSENSUS.
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Quoting kmanhurricaneman:
tomas gonna be one mean sucker, i really am not convinced of that hard right kmanislander, that trough will soon lift out and tomas slip underneath there is a front coming down inthe gulf depending on when it stalls and tomas advancement i feelit will pull him just to the west side of jam and between grand cayman and cayman brac over to cuba and the bahamas.jmo



Richard's evolution really has me second guessing my confidence in the trough. A strong La Nina doesn't help my thoughts either.
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Further ... I cannot help but reflect on the poor guy who was put in charge of the NHC or whatever and tried to make a case for a QUIKSCAT replacement ... he was torpedoed out of office, BUT while argument was made against his position due to heavy Radar around the US and nearby, we out here still have to wait on (now) ASCAT - I understand that our local Doppler Radar funded by the EU is down at this time. I'll stop here as I don't want to be obscene ...
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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.