|
Show Selection: |
| #37158 (Received by flhurricane at: 10:31 AM 03.Aug.2005) TCDAT3 TROPICAL STORM HARVEY DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT WED AUG 03 2005 WHILE THE CYCLONE STILL HAS SUBTROPICAL CHARACTERISTICS... INCLUDING THE LARGE BAND WELL REMOVED FROM THE CENTER TO THE NORTH AND EAST...THE DEFINITION OF THE CIRCULATION CENTER HAS IMPROVED SINCE YESTERDAY. A QUIKSCAT PASS AT 1036Z INDICATED A LARGE AREA OF UNFLAGGED 30 KT WINDS...WITH QUITE A FEW UNFLAGGED 35 KT VECTORS IN THE RELATIVELY DRY SOUTHEASTERN QUADRANT. STORM INTENSITY IS ALSO SUPPORTED BY A 35 KT REPORT FROM SHIP W6SOT AT 12Z NEAR THE CENTER...AND BY A T2.5 DVORAK CLASSIFICATION FROM TAFB. A RECONNAISSANCE AIRCRAFT WILL BE INVESTIGATING HARVEY THIS AFTERNOON. AN UPPER-LEVEL LOW JUST TO THE SOUTH OF HARVEY IS PRODUCING EASTERLY SHEAR AND SUBSIDENCE IN THE CYCLONE'S EASTERN QUADRANT. GLOBAL MODEL GUIDANCE INDICATES THAT THE INFLUENCE OF THE UPPER LOW WILL DIMINISH...BUT THE GUIDANCE ALSO SHOWS MODERATE WESTERLY SHEAR WILL OVERTAKE THE CYCLONE OVER THE NEXT FEW DAYS. THERE COULD BE A BRIEF PERIOD IN A DAY OR SO WHERE THE SHEAR RELAXES AND PERMITS SOME ADDITIONAL STRENGTHENING. THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE SHIPS AND GFDL GUIDANCE. THE INITIAL MOTION ESTIMATE IS 030/9. THERE HAS BEEN LITTLE CHANGE TO THE TRACK FORECAST THINKING. A MID-TROPOSPHERIC SHORTWAVE TROUGH CURRENTLY NEAR THE CANADIAN MARITIMES IS EXPECTED TO MOVE AHEAD OF THE TROPICAL CYCLONE AND THE NEXT UPSTREAM SHORTWAVE SHOULD BE NEARING THE LONGITUDE OF THE CYCLONE IN ABOUT 72 HOURS. ALTHOUGH NEITHER OF THESE TROUGHS HAVE SUFFICIENT AMPLITUDE TO PULL HARVEY INTO THE MID-LATITUDES...THE GUIDANCE INDICATES THAT THERE WILL BE ENOUGH WEST-SOUTHWESTERLY FLOW TO STEER THE TROPICAL CYCLONE ON A NORTHEASTERLY TO EAST-NORTHEASTERLY TRACK OVER THE FORECAST PERIOD. TRACK GUIDANCE CONTINUES TO COME INTO BETTER AGREEMENT AND THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ADVISORY AND THE DYNAMICAL MODEL CONSENSUS. HARVEY IS THE EARLIEST-FORMING EIGHTH TROPICAL STORM ON RECORD. IN THOSE YEARS THAT HAVE HAD AT LEAST EIGHT STORMS...WHICH IS ONLY ABOUT HALF OF ALL SEASONS SINCE 1851...THE MEAN DATE OF FORMATION FOR THE EIGHTH STORM IS SEPTEMBER 29TH. FORECASTER FRANKLIN FORECAST POSITIONS AND MAX WINDS INITIAL 03/1500Z 30.8N 68.0W 35 KT 12HR VT 04/0000Z 31.8N 66.6W 40 KT 24HR VT 04/1200Z 32.6N 64.3W 45 KT 36HR VT 05/0000Z 33.3N 61.7W 40 KT 48HR VT 05/1200Z 34.0N 59.5W 35 KT 72HR VT 06/1200Z 35.5N 56.0W 35 KT 96HR VT 07/1200Z 38.0N 51.0W 30 KT 120HR VT 08/1200Z 41.0N 45.0W 30 KT |
