Unprecedented Hurricane Tomas pounding the Lesser Antilles

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

Share this Blog
7
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1593 - 1543

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35Blog Index

Tomas is likely nearing tropical storm strength. Satellite imagery along with microwave overpasses reveal that the cyclone is not vertically aligned and is tilted towards the northeast (meaning that the mid-level circulation is not directly above the surface one). The convective organization is also rather poor with the circulation at the western edge of an asymmetric CDO. The banding on the western quadrant is also rather poorly organized. This is likely due to some dry air entrainment and about 20 knots of southwesterly vertical wind shear.

Member Since: September 2, 2009 Posts: 130 Comments: 21194
1592. KEEPEROFTHEGATE (Mod)
Quoting Orcasystems:


Not totally true, but regrettably, not that far off. Canada has put a billion into rebuilding the area, but a lot of countries that offered financial support, never actually showed up.

If (when) Haiti gets hit.. its going to be a disaster.

and we will be there again
Member Since: July 15, 2006 Posts: 178 Comments: 56141
please lord dont let it hit hati let it bypass hati before it goes north i hope it goes north and hits me rather than Hati they dont deserve it and i do see a threat to the carolinas down the road thats my neck of the woods
Member Since: September 8, 2010 Posts: 0 Comments: 2232
Thank you for the response Orca. Glad to hear that not everyone dropped the ball.
Member Since: Posts: Comments:
Wind shear should start to clear up in 36 hours. By 60-72 hours conditions will be more favorable than ever.
Member Since: Posts: Comments:
1588. KEEPEROFTHEGATE (Mod)
Quoting weatherwatcher12:
Location of the trough. Also, what is that south of Alaska?
snow for big fish to shovel maybe a nice arctic outflow to follow
Member Since: July 15, 2006 Posts: 178 Comments: 56141
Quoting SunnyDaysFla:
I just do not understand. After it became clear that the buildings in Haiti were devastated by the earthquake, by first thoughts were "how will those people be sheltered with hurricane season less than 5 months away?" Perhaps I missed news reports, but to the best of my knowledge , none of the media covered any efforts to address this almost inevitable ending to the story, nor did any of the aid efforts.


Not totally true, but regrettably, not that far off. Canada has put a billion into rebuilding the area, but a lot of countries that offered financial support, never actually showed up.

If (when) Haiti gets hit.. its going to be a disaster.

Member Since: October 1, 2007 Posts: 81 Comments: 26516
Quoting stormpetrol:
If Tomas has been at 14N for the last 3 advisories, why is still listed as moving WNW?

It's a 12 hour average of movement.
Member Since: May 16, 2009 Posts: 1 Comments: 1231
Location of the trough. Also, what is that south of Alaska?
Member Since: May 16, 2009 Posts: 1 Comments: 1231
Quoting SLU:


OH MY. Where are you getting your pics from?


following links from

http://search.twitter.com/

search for St. Lucia
Member Since: Posts: Comments:
Quoting SLU:


Choc Bridge




Vehicle on Choc Bridge after flood waters receded




Bois D'Orange Bridge


A bit of good news. The phone service at least in the area my family lives is back up. No power as yet though.

That was only a Cat1. Haiti, if the forecast comes true, will experience something much worse.
Member Since: Posts: Comments:
1580. klew136
Quoting Orcasystems:


Thats what I was looking for... thank you :)


yw
Member Since: Posts: Comments:
Quoting klew136:

http://www.untamedskies.com/research.html


Thats what I was looking for... thank you :)
Member Since: October 1, 2007 Posts: 81 Comments: 26516
If Tomas has been at 14N for the last 3 advisories, why is still listed as moving WNW?
Member Since: Posts: Comments:
Quoting CaicosRetiredSailor:
St. Lucia:

After the hurricane in St. Lucia on Twitpic


Cat 1 hurricanes....nothin' to worry about...riiiight!
Member Since: Posts: Comments:
I just do not understand. After it became clear that the buildings in Haiti were devastated by the earthquake, by first thoughts were "how will those people be sheltered with hurricane season less than 5 months away?" Perhaps I missed news reports, but to the best of my knowledge , none of the media covered any efforts to address this almost inevitable ending to the story, nor did any of the aid efforts.
Member Since: Posts: Comments:
1575. KEEPEROFTHEGATE (Mod)
Quoting Cat5hit:


When was the last time Toronto was hit by a hurricane that left nothing but dirt?
never i figure but that can not be said for the caribean its happen lots even columbus wrote of how he visited a village of maybe 15 000 only to return and find it stripped clean with not a soul accounted for after a great wind
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1574. klew136
Quoting Orcasystems:


I have just spent the last 30 minutes trying to find a location for this, so I can put it on my google maps... no luck.

Any kind of geographical information (supported) would be nice.

http://www.untamedskies.com/research.html
Member Since: Posts: Comments:
Quoting scott39:
Yes, The Eastern Caribbean Sea has had a history of killing developing TCs and developed TCs. That is why there is a "grave yard" there. Tomas will go thru the Gauntlet getting beat up, and then come back before landfall.
Yes, those winds are created by the Venezuela land mass, SWesterlies winds in the mid to lower levels they have a tendency to disrupt and even kill a slow moving system. I doubt that "Señor Tomás" will be the exception. He will weaken significantly today; tomorrow as he surpasses the monal Canal longitude, he'll make a comeback to celebrate "EL Dia de los Muertos", an important celebration in our islands.
Member Since: Posts: Comments:
1571. klew136
http://www.untamedskies.com/research.html

great article for hurricane graveyard
Member Since: Posts: Comments:
1570. KEEPEROFTHEGATE (Mod)
Quoting islander101010:
even the best fortune tellers have a bad day thought for sure it would be a major this afternoon. he sure aint no major hurricane

no
he will struggle for the daylight hours
after sunset convective cycle number four
will commence then we will be well on our way
at the moment its a wait watch see
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1569. SLU
Quoting CaicosRetiredSailor:
St. Lucia:

After the hurricane in St. Lucia on Twitpic


OH MY. Where are you getting your pics from?
Member Since: July 13, 2006 Posts: 13 Comments: 5367
Tomas Loop

http://www.ssd.noaa.gov/goes/flt/t2/flash-ft.html
Member Since: Posts: Comments:
1566. KEEPEROFTHEGATE (Mod)
Quoting Cat5hit:


NOW I know why you live in Toronto...
why
Member Since: July 15, 2006 Posts: 178 Comments: 56141
even the best fortune tellers have a bad day thought for sure it would be a major this afternoon. he sure aint no major hurricane
Member Since: Posts: Comments:
While it may appear Florida will not get hit (I fail to see why this is even a problem with people on here)

Haiti will be given a catastrophic blow if this happens


That's all that matters right now.
Member Since: July 8, 2005 Posts: 259 Comments: 24580
Jeeeeeeeezus. Pray for Haiti. They dont need this.
Member Since: Posts: Comments:
1562. IKE
MEMO to JFV and others on here like him: You wanted a hurricane so bad...jump on a boat and go to Haiti and see how bad you want one afterwords.

I feel sorry for those people if the track and strength verifies.
Member Since: Posts: Comments:
St. Lucia:

After the hurricane in St. Lucia on Twitpic
Member Since: Posts: Comments:
Quoting scott39:
Yes, The Eastern Caribbean Sea has had a history of killing developing TCs and developed TCs. That is why there is a "grave yard" there. Tomas will go thru the Gauntlet getting beat up, and then come back before landfall.


I have just spent the last 30 minutes trying to find a location for this, so I can put it on my google maps... no luck.

Any kind of geographical information (supported) would be nice.
Member Since: October 1, 2007 Posts: 81 Comments: 26516
1558. boyzNme
Quoting BahaHurican:
Haiti could be devastated by a TD right now...

And to our fishing Floridian...

Right now it looks like the only way FL would see effects from Tomas would be if it went far enough west to cross western Cuba and then hit the Keys... from that side. If it stays on / east of forecast track, or even goes as far W as central Cuba... it's more likely to keep heading N and NE in response 2 the trough rather than make a NW turn.

So the FL approach currently seems very much an outlier for now, though we know how much things can change...


Thanks Baha for a really good and understandable answer. I didn't ask the question, but appreciate the answer!
Member Since: Posts: Comments:
1556. scott39
Quoting KEEPEROFTHEGATE:
and the end of there world as they know it
Which is already worse than anyone of us can imagine.
Member Since: Posts: Comments:
1555. KEEPEROFTHEGATE (Mod)
remember a hurricane can strip of land of everything including all life so that nothing remains but the dirt and the water
Member Since: July 15, 2006 Posts: 178 Comments: 56141
Quoting KEEPEROFTHEGATE:
and the end of there world as they know it

We can only hope that the trough doesn't begin its southward movement.
Member Since: May 16, 2009 Posts: 1 Comments: 1231
1552. Grenada
Much stronger winds now and heavy rain, six dogs looking for comfort!!!
Member Since: Posts: Comments:
1551. KEEPEROFTHEGATE (Mod)
Quoting Neapolitan:
Of course it may—and almost certainly will—change, but the centerline of the current cone would bring the right (powerful) side of the eyewall directly over Port au Prince.

Yikes...
and the end of there world as they know it
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1550. SLU


Choc Bridge




Vehicle on Choc Bridge after flood waters receded




Bois D'Orange Bridge


A bit of good news. The phone service at least in the area my family lives is back up. No power as yet though.
Member Since: July 13, 2006 Posts: 13 Comments: 5367
1549. scott39
Quoting IKE:


Looking at the 5 day track....aims a major at Haiti.
They need a Shield!
Member Since: Posts: Comments:
1548. KEEPEROFTHEGATE (Mod)
Quoting JRRP:
my only advice to that grapic is

save as many as you can
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1547. scott39
Quoting JRRP:
I also see thier not going with the WSW turn in the track.
Member Since: Posts: Comments:
Of course it may--and almost certainly will--change, but for now the centerline of the cone would bring the right (powerful) side of the eyewall over not just Haiti, but directly into Port au Prince.

I don't say this often, but I am seriously hoping the current situation does not pan out.
Member Since: Posts: Comments:
1545. IKE
Quoting IKE:


Strong trough is going to kick this system north.


Looking at the 5 day track....aims a major at Haiti.
Member Since: Posts: Comments:
1544. KEEPEROFTHEGATE (Mod)
Quoting Orcasystems:


Not true, your from Toronto, so that means your an expert at shovelling snow :)


yes we cut it out
in nice big chunks
and carry it
where we want
to pile it
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1543. scott39
Quoting weatherwatcher12:
What is with this turn?
Is that a "gradual turn"???
Member Since: Posts: Comments:

Viewing: 1593 - 1543

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35Blog Index

Top of Page

About

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

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron