|
Show Selection: |
| #157423 (Received by flhurricane at: 4:40 PM 31.Oct.2007) TCDAT1 TROPICAL STORM NOEL DISCUSSION NUMBER 17 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL162007 500 PM EDT WED OCT 31 2007 THE CENTER OF NOEL DRIFTED WESTWARD FOR A FEW HOURS AROUND MIDDAY...BUT RECENTLY HAS BEEN NEARLY STATIONARY...OR PERHAPS MAKING A SMALL CYCLONIC LOOP...JUST OFFSHORE OF THE NORTH COAST OF CUBA. THE CENTER IS NOT AS WELL CONNECTED TO THE DEEP CONVECTION AS IT WAS SEVERAL HOURS AGO...BUT THE OFFICIAL FORECAST PRESUMES THAT THE TWO WILL NOT COMPLETELY SEPARATE. INDEED...THERE WAS SOME EVIDENCE IN THE RECON DATA AROUND 18Z THAT A SECOND VORTICITY CENTER WAS TRYING TO DEVELOP IN THE CONVECTION TO THE NORTHEAST OF THE SURFACE CENTER. SOUTHWESTERLY FLOW AHEAD OF A MID-LEVEL TROUGH IN THE GULF OF MEXICO IS ADVANCING TOWARD THE CYCLONE...AND THIS IS EXPECTED TO INDUCE A NORTHWARD AND THEN NORTHEASTWARD ACCELERATION OF NOEL. THE OFFICIAL FORECAST FOLLOWS A GFDL/HWRF/GFS BLEND...EXCEPT FOR BEING A LITTLE SLOWER THAN THE GUIDANCE AND THE PREVIOUS FORECAST DURING THE FIRST 24 HOURS. THE INITIAL INTENSITY REMAINS 45 KT BASED ON FLIGHT-LEVEL AND SFMR DATA. THERE COULD BE SOME STRENGTHENING DURING THE NEXT 24 HOURS...BEFORE SOUTHWESTERLY SHEAR INCREASES AND EXTRATROPICAL TRANSITION BEGINS. GLOBAL MODEL GUIDANCE CONTINUES TO INDICATE NOEL WILL BECOME A VIGOROUS EXTRATROPICAL CYCLONE. WINDS ASSOCIATED WITH THE ENVIRONMENTAL PRESSURE GRADIENT HAVE DECREASED BELOW GALE FORCE ALONG THE SOUTHEAST FLORIDA COAST. RECONNAISSANCE DATA INDICATE THAT THE WIND FIELD OF NOEL HAS EXPANDED IN THE NORTHWEST QUADRANT...AND THE OFFICIAL FORECAST NOW BRINGS TROPICAL STORM WINDS TO NEAR THE SOUTHEAST FLORIDA COAST. SINCE ANY SUBSEQUENT INCREASE IN WINDS AT THE COAST WOULD BE ASSOCIATED WITH THE TROPICAL STORM...A TROPICAL STORM WATCH IS BEING ISSUED AT THIS TIME. WHILE A WATCH IS USUALLY ASSOCIATED WITH A LONGER LEAD TIME THAN A WARNING...IT ALSO CONVEYS THE POSSIBILITY...AS OPPOSED TO THE EXPECTATION...OF TROPICAL STORM CONDITIONS. BECAUSE THE TROPICAL STORM FORCE WIND RADII ARE FORECAST TO REMAIN OFFSHORE...A WATCH IS MORE APPROPRIATE THAN A WARNING. THE NEED FOR A WARNING WILL BE REASSESSED THIS EVENING. FORECAST POSITIONS AND MAX WINDS INITIAL 31/2100Z 22.6N 78.8W 45 KT 12HR VT 01/0600Z 23.5N 79.0W 50 KT 24HR VT 01/1800Z 25.3N 78.1W 55 KT 36HR VT 02/0600Z 28.0N 76.0W 50 KT 48HR VT 02/1800Z 31.5N 72.5W 55 KT...EXTRATROPICAL 72HR VT 03/1800Z 39.0N 66.0W 60 KT...EXTRATROPICAL 96HR VT 04/1800Z 49.0N 57.5W 60 KT...EXTRATROPICAL 120HR VT 05/1800Z 60.0N 47.5W 60 KT...EXTRATROPICAL $$ FORECASTER FRANKLIN |
