[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 300245
TCDAT1
TROPICAL STORM TOMAS DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL212010
1100 PM AST FRI OCT 29 2010

AS MENTIONED IN THE 0000 UTC SPECIAL ADVISORY...THE AIR FORCE
RECONNAISSANCE AIRCRAFT REPORTED A MAXIMUM FLIGHT-LEVEL WIND OF 61
KT AND SFMR MEASUREMENTS BETWEEN 50-55 KT...ALBEIT IN SOME HEAVY
RAIN...ON THE LAST PASS THROUGH THE CENTER.  DEEP CONVECTION HAS
CONTINUED TO INCREASE SINCE THAT TIME WITH A PROMINENT BAND FORMING
OVER THE WESTERN SEMICIRCLE...SO THE INITIAL INTENSITY IS BEING
RAISED TO 55 KT ON THIS ADVISORY.

TOMAS IS BENEFITING FROM EXCELLENT UPPER-LEVEL OUTFLOW IN ALMOST ALL
QUADRANTS...AND THE CYCLONE APPEARS AS THOUGH IT IS GOING THROUGH A
PERIOD OF RAPID INTENSIFICATION.  SHIPS RI GUIDANCE IS INDICATING
AT LEAST A 40 PERCENT CHANCE OF A 30-KT INCREASE IN INTENSITY OVER
THE NEXT 24 HOURS...AND IT IS LIKELY THAT TOMAS WILL REACH
HURRICANE STRENGTH WITHIN THE NEXT 12-24 HOURS.  AFTER 24
HOURS...NEARLY ALL THE INTENSITY GUIDANCE SHOWS THE INTENSITY
LEVELING OFF OR ONLY INCREASING MORE MODESTLY THROUGH 120 HOURS.
HOWEVER...GLOBAL MODEL FIELDS SHOW THE ENVIRONMENT OVER THE
CARIBBEAN BECOMING FAVORABLE FOR CONTINUED INTENSIFICATION...AND IT
IS NOT OBVIOUS AT THIS POINT WHAT MIGHT LIMIT THAT TREND.  THE
OFFICIAL FORECAST CONTINUES TO SHOW STEADY STRENGTHENING TO
CATEGORY 3 STRENGTH BY DAY 4 AND REMAINS ABOVE ALL THE RELIABLE
INTENSITY MODELS.

THE CENTER APPEARED TO HAVE REFORMED TO THE NORTH EARLIER THIS
EVENING...AND THE INITIAL MOTION IS ESTIMATED AT 300/14.  THE NEW
OFFICIAL TRACK FORECAST REMAINS LARGELY UNCHANGED FROM THE
PREVIOUS FORECAST...ALTHOUGH THE FIRST 12-24 HOURS OF THE TRACK
FORECAST HAVE BEEN SHIFTED A LITTLE TO THE NORTH AS AN ARTIFACT OF
THE REFORMATION OF THE CENTER.  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.

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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