| 5 Day Track: http://www.nhc.noaa.gov/refresh/graphics_at1+shtml/023914.shtml?5day?large#contents ------------------------------------------ TROPICAL STORM TOMAS DISCUSSION NUMBER 28 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1100 PM EDT THU NOV 04 2010 THERE HAS BEEN A SHARP INCREASE IN THE INNER-CORE WIND STRUCTURE AND CONVECTIVE ORGANIZATION OF TOMAS DURING THE PAST 6 HOURS. ALTHOUGH BOTH AIR FORCE RESERVE AND NOAA HURRICANE AIRCRAFT INDICATE THERE IS ABOUT 12 NMI NORTHEASTWARD TILT TO THE VORTEX...THIS HAS NOT PREVENTED THE CENTRAL PRESSURE FROM FALLING AND THE WINDS FROM INCREASING. THE MAXIMUM 850-MB FLIGHT-LEVEL WINDS REPORTED BY THE AIR FORCE WAS 61 KT...AND 58 KT WAS REPORTED AT 700 MB BY THE NOAA HURRICANE HUNTERS. MAXIMUM SFMR WINDS HAVE BEEN AROUND 56-58 KT. THE LATEST NOAA RECON PRESSURE WAS DOWN TO 989 MB...AND THAT WAS WITH 13 KT OF WIND AT THE SURFACE. A COMBINATION OF THESE DATA EASILY SUPPORT INCREASING THE INTENSITY TO 55 KT...WHICH COULD BE A LITTLE CONSERVATIVE GIVEN THAT A WARM SPOT HAS APPEARED INTERMITTENTLY WITHIN A RING OF VERY COLD TOPS OF -80C TO -85C NEAR THE CENTER. THE INITIAL MOTION ESTIMATE IS NOW 030/08. TOMAS HAS NOW MOVED NORTH OF A MID-LEVEL RIDGE THAT LIES EAST-WEST ACROSS THE CENTRAL CARIBBEAN SEA. TOMAS SHOULD CONTINUE TO MOVE AROUND THE WESTERN PERIPHERY OF THE RIDGE AND GRADUALLY ACCELERATE NORTHEASTWARD AS IT COMES UNDER THE INFLUENCE OF MODERATE SOUTHWESTERLY FLOW AHEAD OF A DEEP MID-LATITUDE TROUGH CURRENTLY MOVING EASTWARD ACROSS THE EASTERN U.S....FLORIDA...AND THE EASTERN GULF OF MEXICO. THE TRACK MODELS REMAIN IN EXCELLENT AGREEMENT ON THIS DEVELOPING SCENARIO THROUGH 48 HOURS...AND THE MODEL TRACKS HAVE EVEN SHIFTED MORE TO THE EAST ON THE LATEST FORECAST CYCLE. HOWEVER...AFTER THAT TIME... HOWLING WESTERLY WIND SHEAR IN EXCESS OF 60 KT IS EXPECTED TO SHEAR APART TOMAS AND LEAVE BEHIND A REMNANT LOW PRESSURE SYSTEM THAT SHOULD BE STEERED SLOWLY EASTWARD BY WEAKER LOW-LEVEL WESTERLY FLOW ON THE SOUTH SIDE OF AN EXTRATROPICAL LOW PRESSURE SYSTEM. THE GFDL AND HWRF MODELS TAKE TOMAS OR ITS REMNANTS RAPIDLY NORTHWARD AND MERGE IT WITH A DEEP EXTRATROPICAL LOW NEAR THE NORTHEAST U.S. COAST AND THE CANADIAN MARITIMES. HOWEVER...THE GFS...ECMWF... UKMET...AND NOGAPS MODELS SHOW TOMAS SHEARING APART AND REMAINING JUST NORTH OF THE GREATER ANTILLES. THE LATTER SCENARIO IS PREFERRED GIVEN THE EXTREMELY HOSTILE SHEAR CONDITIONS THAT ARE FORECAST TO AFFECT THE CYCLONE BY 72 HOURS AND BEYOND. THE OFFICIAL FORECAST TRACK HAS BEEN SHIFTED A LITTLE TO THE RIGHT OF THE PREVIOUS TRACK...BUT MAINLY TO ACCOUNT FOR THE MORE EASTERLY INITIAL POSITION. TOMAS HAS ABOUT 24 HOURS OR SO TO STRENGTHEN OVER 29C SSTS AND IN A RELATIVELY LOW SHEAR ENVIRONMENT. HOWEVER...BY 36 HOURS...MID-LEVEL HUMIDITIES ARE FORECAST TO DECREASE BELOW 40 PERCENT...WHICH COULD ACT TO ERODE THE INNER-CORE CONVECTION. AS MENTIONED ABOVE...BY 48 HOURS THE VERTICAL SHEAR IS EXPECTED TO INCREASE SHARPLY AND TOMAS SHOULD BEGIN A STEADY WEAKENING TREND. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO BUT SLIGHTLY LOWER THAN THE SHIPS...LGEM... AND GFDL MODELS. REGARDLESS OF THE EXACT TRACK AND INTENSITY OF TOMAS...THE MOST SIGNIFICANT THREAT FROM THIS TROPICAL CYCLONE WILL BE HEAVY RAINFALL...WHICH COULD PRODUCE FLASH FLOODING AND LIFE-THREATENING MUD SLIDES OVER HAITI AND THE DOMINICAN REPUBLIC DURING THE NEXT COUPLE OF DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 05/0300Z 17.3N 75.5W 55 KT 12HR VT 05/1200Z 18.8N 74.6W 65 KT 24HR VT 06/0000Z 21.0N 73.1W 70 KT 36HR VT 06/1200Z 23.4N 71.5W 70 KT 48HR VT 07/0000Z 25.1N 70.2W 55 KT 72HR VT 08/0000Z 27.2N 67.9W 40 KT 96HR VT 09/0000Z 28.3N 65.8W 30 KT...POST-TROPICAL 120HR VT 10/0000Z 28.5N 64.0W 30 KT...POST-TROP/REMNT LOW $$ FORECASTER STEWART ------------------------------------------ TROPICAL STORM TOMAS ADVISORY NUMBER 28 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL212010 1100 PM EDT THU NOV 04 2010 ...TOMAS STRENGTHENING AS IT MOVES NORTH-NORTHEASTWARD TOWARD EASTERN JAMAICA AND WESTERN HAITI...TROPICAL-STORM-FORCE WINDS NOW OCCURRING ALONG THE SOUTHWESTERN COAST OF HAITI... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...17.3N 75.5W ABOUT 100 MI...160 KM ESE OF KINGSTON JAMAICA ABOUT 230 MI...370 KM WSW OF PORT AU PRINCE HAITI MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/HR PRESENT MOVEMENT...NNE OR 30 DEGREES AT 9 MPH...15 KM/HR MINIMUM CENTRAL PRESSURE...989 MB...29.21 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY... NONE. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A HURRICANE WARNING IS IN EFFECT FOR... * HAITI * THE SOUTHEASTERN BAHAMAS...AND THE TURKS AND CAICOS ISLANDS * THE CUBAN PROVINCE OF GUANTANAMO A TROPICAL STORM WARNING IS IN EFFECT FOR... * JAMAICA * THE CUBAN PROVINCES OF SANTIAGO DE CUBA AND HOLGUIN A TROPICAL STORM WATCH IS IN EFFECT FOR... * THE SOUTHERN COAST OF THE DOMINICAN REPUBLIC FROM THE HAITI BORDER EASTWARD TO BARAHONA A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN 12 TO 36 HOURS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION. A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN THE NEXT 12 TO 24 HOURS. A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE WITHIN 24 TO 36 HOURS. FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 1100 PM EDT...0300 UTC...THE CENTER OF TROPICAL STORM TOMAS WAS LOCATED NEAR LATITUDE 17.3 NORTH...LONGITUDE 75.5 WEST. TOMAS IS MOVING TOWARD THE NORTH-NORTHEAST NEAR 9 MPH...15 KM/HR. A TURN TOWARD THE NORTHEAST WITH AN INCREASE IN FORWARD SPEED IS EXPECTED OVER THE NEXT 48 HOURS. ON THE FORECAST TRACK...THE CENTER OF TOMAS WILL PASS NEAR EASTERN JAMAICA OR WESTERN HAITI TONIGHT AND EARLY FRIDAY...NEAR OR OVER EXTREME EASTERN CUBA FRIDAY AFTERNOON...AND NEAR OR OVER THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS FRIDAY NIGHT. RECENT REPORTS FROM A NOAA HURRICANE HUNTER AIRCRAFT INDICATE THAT MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 65 MPH...100 KM/HR ...WITH HIGHER GUSTS. ADDITIONAL STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND TOMAS COULD BECOME A HURRICANE ON FRIDAY AS THE CENTER PASSES HAITI AND EASTERN CUBA...AND MOVES ACROSS THE SOUTHEASTERN BAHAMAS. TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 140 MILES... 220 KM...ESPECIALLY NORTHEAST THROUGH SOUTHEAST OF THE CENTER. THE MINIMUM CENTRAL PRESSURE RECENTLY MEASURED BY A NOAA HURRICANE HUNTER AIRCRAFT IS 989 MB...29.21 INCHES. HAZARDS AFFECTING LAND ---------------------- STORM SURGE...A DANGEROUS STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 1 TO 3 FEET ABOVE NORMAL TIDE LEVELS IN THE WARNING AREA ALONG THE COAST OF HAITI...AND 3 TO 5 FEET ALONG THE SOUTHEASTERN COAST OF CUBA...IN AREAS OF ONSHORE WINDS. NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DESTRUCTIVE WAVES. WIND...TROPICAL STORM CONDITIONS ARE OCCURRING WITHIN THE TROPICAL STORM WARNING AREA AND IN THE HURRICANE WARNING AREA IN HAITI. HURRICANE CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE HURRICANE WARNING AREA ON FRIDAY. RAINFALL...TOMAS IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 5 TO 10 INCHES OVER MUCH OF HAITI AND THE DOMINICAN REPUBLIC... WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 15 INCHES. THESE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES OVER MOUNTAINOUS TERRAIN. TOTAL RAINFALL ACCUMULATIONS OF 1 TO 3 INCHES ARE POSSIBLE OVER JAMAICA. RAINFALL TOTALS OF 3 TO 6 INCHES ARE POSSIBLE OVER EASTERN CUBA...THE SOUTHEASTERN BAHAMAS...AND THE TURKS AND CAICOS ISLANDS. NEXT ADVISORY ------------- NEXT INTERMEDIATE ADVISORY...200 AM EDT. NEXT COMPLETE ADVISORY...500 AM EDT. $$ FORECASTER STEWART |