Show Selection: |
#382860 (Received by flhurricane at: 5:00 AM 13.Oct.2010) TCDAT3 HURRICANE PAULA DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL182010 400 AM CDT WED OCT 13 2010 AN AIR FORCE RESERVE UNIT HURRICANE HUNTER AIRCRAFT INVESTIGATING PAULA THIS MORNING INDICATES THAT THE HURRICANE HAS CHANGED LITTLE SINCE YESTERDAY AFTERNOON. MAXIMUM 700 MB FLIGHT-LEVEL WINDS OBSERVED IN THE NORTHEASTERN QUADRANT WERE 96 KT...WHICH EQUATES TO ABOUT AN 86-KT SURFACE WIND. THE HIGHEST SFMR SURFACE WINDS OBSERVED WERE 81-82 KT. BASED ON THE RECON INFORMATION...ALONG WITH THE FACT THAT CLOUD TOPS NEAR THE CENTER OF PAULA HAVE BEEN COOLING DURING THE PAST 3 HOURS...THE INITIAL INTENSITY WILL REMAIN AT 85 KT. ALTHOUGH THE CENTRAL PRESSURE HAS RISEN BY 3 MB SINCE YESTERDAY...THE CYCLONE IS NOW ALSO EMBEDDED WITHIN A FIELD OF HIGHER ENVIRONMENTAL PRESSURES...WHICH HAS KEPT THE PRESSURE GRADIENT NEARLY CONSTANT. THE INITIAL MOTION ESTIMATE IS 360/8. FOR THE NEXT 12-24 HOURS... PAULA IS EXPECTED TO MOVE TOWARD THE NORTH AND THEN THE NORTHEAST AROUND THE WESTERN PERIPHERY OF A DEEP-LAYER ANTICYCLONE CENTERED OVER THE WINDWARD PASSAGE. BY 36 HOURS...PAULA IS FORECAST TO TURN EASTWARD AS THE HURRICANE COMES UNDER THE INFLUENCE OF WESTERLY MID-LEVEL FLOW AHEAD OF AN EASTWARD-MOVING SHORTWAVE TROUGH CURRENTLY LOCATED OVER THE SOUTHEASTERN U.S. AND EXTENDING SOUTHWARD INTO THE CENTRAL GULF OF MEXICO. THE MODELS ARE IN GOOD AGREEMENT ON THIS GENERAL SCENARIO...BUT DIFFER IN THE EXACT TIMING OF THE EASTWARD TURN. THE OVERALL MODEL GUIDANCE SUITE HAS SHIFTED NORTHWARD...DUE IN LARGE PART TO NORTHWARD SHIFT OF THE HWRF MODEL. BOTH THE GFDL AND HWRF MODELS BRING PAULA JUST SOUTH OF THE LOWER AND MIDDLE FLORIDA KEYS...WHEREAS THE GFS-ENSEMBLE MEAN AND BAM DEEP MODELS BRING PAULA ACROSS EXTREME SOUTHERN FLORIDA. THE LATTER MODEL SCENARIOS SEEM UNREASONABLE AT THIS TIME GIVEN THE MODERATE WESTERLY MID-LEVEL FLOW THAT IS FORECAST TO DEVELOP ACROSS THE FLORIDA PENINSULA...THE KEYS...AND THE FLORIDA STRAITS. ALTHOUGH THE CONSENSUS MODEL...TVCN...HAS SHIFTED NORTHWARD...THE OFFICIAL FORECAST TRACK WILL REMAIN SOUTH OF THAT MODEL AND NEAR THE NORTHERN COAST OF CUBA THROUGH 48 HOURS BASED ON THE AFOREMENTIONED WESTERLY FLOW THAT IS EXPECTED TO DEVELOP NORTH OF 23N LATITUDE AND THE POSSIBILITY THAT PAULA MAY WEAKEN SOONER THAN EXPECTED AND BE PUSHED SOUTHWARD BY A STRONG SURFACE HIGH THAT WILL BE OVERSPREADING THE ENTIRE GULF OF MEXICO. PAULA HAS LIKELY PEAKED IN INTENSITY NOW THAT THE VERTICAL SHEAR HAS INCREASED TO NEAR 25 KT AND RECON INDICATED THE EYEWALL WAS OPEN TO THE SOUTH AND SOUTHEAST. INCREASING SOUTHWESTERLY AND THEN WESTERLY SHEAR EXCEEDING 30 KT SHOULD BEGIN TO TAKE ITS TOLL ON PAULA DUE TO VERY SMALL SIZE OF THE CYCLONE DURING THE NEXT DAY OR SO. IF PAULA INTERACTS WITH LAND SOONER THAN EXPECTED...THEN MORE RAPID WEAKENING WOULD OCCUR...ESPECIALLY GIVEN THE EXTREMELY SMALL SIZE OF THE WIND FIELD. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND IS IN GOOD AGREEMENT WITH THE LGEM AND SHIPS INTENSITY MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 13/0900Z 20.7N 86.0W 85 KT 12HR VT 13/1800Z 21.5N 85.8W 80 KT 24HR VT 14/0600Z 22.3N 85.0W 70 KT 36HR VT 14/1800Z 23.0N 83.6W 60 KT 48HR VT 15/0600Z 23.2N 82.5W 50 KT 72HR VT 16/0600Z 22.9N 80.5W 35 KT...INLAND 96HR VT 17/0600Z 22.0N 79.5W 30 KT...INLAND 120HR VT 18/0600Z...DISSIPATED $$ FORECASTER STEWART |