000 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