000 WTNT41 KNHC 032057 TCDAT1 TROPICAL STORM TOMAS DISCUSSION NUMBER 23 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 500 PM EDT WED NOV 03 2010 AFTER STRUGGLING TO MAINTAIN ITS IDENTITY THIS MORNING...TOMAS HAS RE-ORGANIZED DURING THE AFTERNOON. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT HAS FOUND A BETTER-DEFINED CIRCULATION THAN WAS PRESENT DURING THE PREVIOUS AIRCRAFT MISSION...ALTHOUGH THE LIGHT AND VARIABLE WIND CENTER IS STILL RATHER LARGE. THE PLANE FOUND FLIGHT-LEVEL WINDS OF 48 KT BELOW 1500 FT AND ESTIMATED SURFACE WINDS NEAR 40 KT FROM THE SFMR ABOUT 45 N MI EAST OF THE MEAN CENTER. THE MINIMUM CENTRAL PRESSURE WAS 1003 MB. BASED ON THESE DATA...TOMAS IS UPGRADED TO A 40-KT TROPICAL STORM. WITH THE RE-FORMATION OF THE CENTER TO THE EAST OF THE PREVIOUS ADVISORY POSITION...THE INITIAL MOTION IS NOW AN UNCERTAIN 335/5. A DEEP-LAYER TROUGH AND ACCOMPANYING COLD FRONT MOVING THROUGH THE GULF OF MEXICO AND THE SOUTHEASTERN UNITED STATES SHOULD CAUSE TOMAS TO RECURVE TOWARD THE NORTHEAST DURING THE NEXT 48 HR...WITH A GENERALLY NORTHEASTWARD MOTION CONTINUING THROUGH 72-96 HR. THERE HAS BEEN A SIGNIFICANT CHANGE IN THE TRACK GUIDANCE SINCE THE PREVIOUS ADVISORY...WITH THE LATEST MODEL RUNS IN GOOD AGREEMENT ON A FASTER MOTION IN THE FIRST 72-96 HR. INDEED THE NOGAPS...WHICH PREVIOUSLY CALLED FOR TOMAS TO SHEAR APART AND TURN SOUTHWEST... NOW CALLS FOR THE STORM TO MOVE STEADILY NORTHEASTWARD THROUGH THE FORECAST PERIOD. BASED ON THIS...THE NEW FORECAST TRACK IS FASTER THAN THE PREVIOUS TRACK THROUGH 96 HR. AFTER THAT TIME...THE GUIDANCE REMAINS VERY DIVERGENT. THE UKMET CONTINUES TO FORECAST TOMAS TO SHEAR APART WITH THE LOW-LEVEL CIRCULATION MOVING SOUTHWESTWARD...WHILE THE CANADIAN FORECAST TOMAS OR ITS EXTRATROPICAL REMNANTS TO REACH NEWFOUNDLAND BY 120 HR. THE OTHER MODELS ARE IN BETWEEN THESE RATHER DRASTIC EXTREMES. THE INTENSITY FORECAST WILL FOLLOW THE SCENARIO OF THE PREVIOUS ADVISORY OF A SLOW EASTWARD MOTION AFTER 96 HR AT A HIGHER LATITUDE THAN PREVIOUSLY FORECAST. NOW THAT TOMAS IS CONSOLIDATING...LIGHT VERTICAL WIND SHEAR AND WARM SEA SURFACE TEMPERATURES FAVOR INTENSIFICATION. THE SHIPS RAPID INTENSIFICATION INDEX SHOWS A 50 PERCENT CHANCE OF 30 KT OF STRENGTHENING DURING THE NEXT 24 HR...ALTHOUGH THE CURRENT ORGANIZATION OF TOMAS ARGUES AGAINST THAT MUCH INTENSIFICATION. THE NEW INTENSITY FORECAST IS A COMPROMISE BETWEEN THE SHIPS AND LGEM MODELS FOR THE FIRST 36-48 HR...CALLING FOR TOMAS TO STRENGTHEN UNTIL LAND INTERACTION WITH HISPANIOLA BEGINS. IT IS NOT OUT OF THE QUESTION THAT TOMAS COULD BECOME A HURRICANE BEFORE REACHING LAND AS FORECAST BY THE SHIPS AND GFDL MODELS. AFTER PASSING HISPANIOLA...INCREASING SOUTHWESTERLY WIND SHEAR IS EXPECTED TO CAUSE TOMAS TO WEAKEN. THE NEW INTENSITY FORECAST IS AGAIN CLOSE TO BUT SLIGHTLY LOWER THAN THE INTENSITY CONSENSUS MODEL ICON. REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE TROPICAL CYCLONE WILL POSE A SIGNIFICANT THREAT OF HEAVY RAINFALL... FLOODING...AND POTENTIAL MUD SLIDES OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT FEW DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 03/2100Z 14.9N 74.8W 40 KT 12HR VT 04/0600Z 15.8N 75.0W 45 KT 24HR VT 04/1800Z 16.9N 75.0W 50 KT 36HR VT 05/0600Z 18.4N 74.5W 55 KT 48HR VT 05/1800Z 20.2N 73.2W 60 KT 72HR VT 06/1800Z 23.5N 71.0W 60 KT 96HR VT 07/1800Z 26.0N 69.0W 55 KT 120HR VT 08/1800Z 26.0N 67.0W 45 KT $$ FORECASTER BEVEN