000
WTNT41 KNHC 040249
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER  24
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM EDT WED NOV 03 2010
 
DATA FROM NOAA AND AIR FORCE RESERVE HURRICANE HUNTER MISSIONS
INDICATE THAT THE LOW-LEVEL CENTER OF TOMAS IS STILL NOT QUITE
ALIGNED WITH THE MID-LEVEL CENTER.  THEY HAVE MOVED CLOSER TOGETHER
DURING THE DAY...HOWEVER...AND A 2219 UTC SSMI/S MICROWAVE PASS
SHOWS CONSIDERABLY MORE BANDING THAN THIS SYSTEM HAS HAD DURING THE
PAST FEW DAYS. THE INITIAL WIND SPEED WILL REMAIN 40 KT...WHICH IS
NEAR THE FLIGHT-LEVEL AND SFMR MAXIMA REPORTED BY NOAA.
 
THE LARGE-SCALE ENVIRONMENT IS FAVORABLE FOR STRENGTHENING OF TOMAS
WITH LIGHT SOUTHWESTERLY SHEAR AND WARM WATERS.  IN FACT...ALL OF
THE RELIABLE MODELS THAT DO NOT MOVE TOMAS OVER A SIGNIFICANT
PORTION OF HAITI MAKE THE CYCLONE A HURRICANE WITHIN 36-48 HOURS. 
THE SHIPS RAPID INTENSIFICATION INDEX ALSO SHOWS A 62 PERCENT
CHANCE OF A 30-KT INCREASE WITHIN THE NEXT 24 HOURS...THOUGH THIS
MODEL WAS TOO HIGH YESTERDAY.  THIS SYSTEM HAS BURNED US BEFORE BY
DOING THE EXACT OPPOSITE OF THE GUIDANCE...BUT GIVEN THE IMPROVED
MICROWAVE PRESENTATION...I AM INCLINED TO RAISE THE FORECAST A
LITTLE BIT TO HURRICANE STATUS.  THE NEW FORECAST IS NEAR OR
SLIGHTLY BELOW A COMPOSITE OF THE GFDL...SHIPS...AND LGEM MODELS. 
WEAKENING IS FORECAST AT THE END OF THE PERIOD AS THE TROPICAL
CYCLONE INTERACTS WITH A COLD FRONT AND VERTICAL WIND SHEAR
INCREASES.
 
THE CURRENT MOTION REMAINS 330/5...THOUGH THIS IS MORE UNCERTAIN
THAN NORMAL WITH THE NHC INITIAL POSITION ON THE NORTHEASTERN SIDE
OF THE BROAD LOW-LEVEL CIRCULATION.  A WEAK RIDGE TO THE EAST OF
TOMAS IS STEERING THE STORM FOR NOW...BUT A RATHER STRONG DEEP
LAYER LOW OVER THE GULF OF MEXICO IS EXPECTED TO CAUSE THE TROPICAL
CYCLONE TO TURN TOWARD THE NORTH TOMORROW...AND THE NORTH-NORTHEAST
BY EARLY FRIDAY.  TOMAS SHOULD BE ACCELERATING AS IT PASSES NEAR
HAITI AS THE MID-LATITUDE LOW APPROACHES.  ONLY COSMETIC CHANGES
WERE MADE TO THE NHC FORECAST WITH THE MOST RELIABLE MODELS STILL
FOCUSED ON A TRACK TOWARD SOUTHWESTERN HAITI.  AT DAYS 4 AND
5...THERE ARE SOME INDICATIONS FROM THE MODELS THAT THE GULF OF
MEXICO LOW WILL LEAVE TOMAS BEHIND TO THE EAST OF THE BAHAMAS...AND
THE OFFICIAL FORECAST IS SHIFTED TO THE RIGHT AT THAT TIME.
 
REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL
CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL...
FLOODING...AND LIFE-THREATENING MUD SLIDES OVER HAITI AND THE
DOMINICAN REPUBLIC DURING THE NEXT FEW DAYS.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/0300Z 15.4N  75.2W    40 KT
 12HR VT     04/1200Z 16.1N  75.4W    45 KT
 24HR VT     05/0000Z 17.4N  75.0W    55 KT
 36HR VT     05/1200Z 19.1N  74.0W    65 KT
 48HR VT     06/0000Z 21.0N  72.5W    65 KT
 72HR VT     07/0000Z 24.0N  70.5W    65 KT
 96HR VT     08/0000Z 25.0N  68.5W    55 KT
120HR VT     09/0000Z 25.0N  66.5W    45 KT
 
$$
FORECASTER BLAKE