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| #9906 (Received by flhurricane at: 11:18 AM 24.Sep.2004) TCDAT1 HURRICANE JEANNE DISCUSSION NUMBER 44 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT FRI SEP 24 2004 SATELLITE IMAGERY INDICATES THE EYE AND THE INNER-CORE CONVECTION HAS BEEN ERODED BY DRY AIR WRAPPING INTO THE CENTER. HOWEVER...THE CONVECTIVE BANDING FEATURES HAVE IMPROVED...SUGGESTING THAT THE CIRCULATION HAS INCREASED OR AT LEAST HAS REMAINED STEADY. THEREFORE ...THE INITIAL INTENSITY REMAINS AT 85 KT...WHICH MAY STILL BE A LITTLE GENEROUS. NEXT RECON FLIGHT WILL AT 24/18Z. THE INITIAL MOTION IS 270/8. UPPER-AIR DATA THIS MORNING INDICATE A DEEP-LAYER HIGH/RIDGE WAS CENTERED JUST EAST OF THE DELMARVA... WHICH IS SOUTHEAST OF MOST OF THE NHC MODEL FORECAST POSITIONS... ESPECIALLY THE UKMET...THAT ARE VALID AT THAT TIME. ALSO...THE MID-LEVEL WINDS ACROSS THE FLORIDA HAVE BACKED AROUND FROM THE NORTHEAST TO THE NORTH DURING THE PAST 12 HOURS AS AN INVERTED TROUGH HAS MOVED WESTWARD TO THE FLORIDA EAST COAST. AS THIS FEATURE CONTINUES TO MOVE WESTWARD...SOME WEAK RIDGING SHOULD OCCUR BEHIND IT OVER AND EAST OF THE FLORIDA PENINSULA...WHICH MAY ACT TO FORCE JEANNE A LITTLE SOUTH OF DUE WEST IN THE SHORT TERM. BASED ON THE TRENDS NOTED IN THE 12Z UPPER-AIR DATA...NO SIGNIFICANT CHANGE WAS MADE TO THE PREVIOUS FORECAST TRACK...EVEN THOUGH THE 06Z MODEL GUIDANCE SHIFTED SLIGHTLY TO THE NORTH AND EAST. THE INTENSITY FORECAST REMAINS A LITTLE TRICKY. DUE TO THE NEARLY STATIONARY MOTION OF JEANNE THE PREVIOUS FEW DAYS...SIGNIFICANT COLD UPWELLING HAS OCCURRED BENEATH THE HURRICANE. HOWEVER...LATEST SUBJECTIVE SST ANALYSES BASED ON BUOY AND SHIP OBS INDICATE JEANNE IS BEGINNING TO MOVE FROM A REGION OF 79F SSTS TOWARD WARMER WATER. AN EAST-WEST SST THERMAL RIDGE ALSO EXTENDS JUST NORTH OF 26N LATITUDE...ALONG THE PATH THAT JEANNE IS EXPECTED TO TAKE. SSTS CONTINUE TO INCREASE TO 84F OVER THE NORTHERN BAHAMAS. THIS WOULD GENERALLY SUGGEST THAT STEADY INTENSIFICATION SHOULD OCCUR... ESPECIALLY GIVEN THE FAVORABLE UPPER-LEVEL OUTFLOW PATTERN. THE MAIN HINDERING INFLUENCE NOW APPEARS TO BE THE DRY AIR SURROUNDING JEANNE THAT HAS GRADUALLY BEEN WORKING ITS WAY INTO THE CENTER. UNTIL THIS DRY AIR MIXES OUT...LITTLE OR NO STRENGTHENING SHOULD OCCUR. THE INTENSITY FORECAST CLOSELY FOLLOWS THE SHIPS INTENSITY MODEL...WITH ANY SIGNIFICANT INTENSIFICATION LIKELY NOT OCCURRING UNTIL JEANNE REACHES THE NORTHERN BAHAMAS. JUST PRIOR TO LANDFALL ...SOUTHWESTERLY SHEAR MAY INITIATE A WEAKENING TREND. HOWEVER... JEANNE COULD STILL BECOME A MAJOR HURRICANE OVER THE BAHAMAS AND/OR JUST PRIOR TO LANDFALL. NOTE...IF EXPECTED LANDFALL OCCURS A LITTLE LATER THAN CURRENTLY FORECAST...THEN THE INTENSITIES BEYOND 48 HOURS WOULD BE HIGHER. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 24/1500Z 26.2N 72.4W 85 KT 12HR VT 25/0000Z 26.2N 74.1W 85 KT 24HR VT 25/1200Z 26.4N 76.6W 90 KT 36HR VT 26/0000Z 26.8N 78.9W 95 KT 48HR VT 26/1200Z 27.9N 80.7W 95 KT...INLAND 72HR VT 27/1200Z 30.7N 81.9W 65 KT...INLAND 96HR VT 28/1200Z 34.5N 78.0W 45 KT...INLAND 120HR VT 29/1200Z 40.0N 69.5W 35 KT...OVER WATER |
