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| #213409 (Received by flhurricane at: 10:46 PM 03.Sep.2008) TCDAT5 TROPICAL STORM JOSEPHINE DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102008 1100 PM EDT WED SEP 03 2008 THE LATEST SATELLITE PICTURES SHOW A RATHER UNIMPRESSIVE TROPICAL CYCLONE PATTERN WITH NO BANDING FEATURES AND ONLY A STRETCHED BURST OF CONVECTION NEAR THE CENTER. DVORAK SATELLITE CLASSIFICATIONS HAVE COME DOWN FROM SAB/TAFB...AND THE INITIAL INTENSITY IS LOWERED TO 45 KT IN LINE WITH THOSE ESTIMATES. AN UPPER TROUGH TO THE WEST OF JOSEPHINE CONTINUES TO SHEAR THE STORM. THIS FEATURE SHOULD BE THE MAIN FACTOR TO MODULATE THE INTENSITY OF THE TROPICAL CYCLONE FOR THE NEXT SEVERAL DAYS AS SOUTHWESTERLY SHEAR IS FORECAST TO PERSIST. THUS A SLOW WEAKENING IS FORECAST...AND THE NHC FORECAST IS IN GOOD AGREEMENT WITH THE INTENSITY GUIDANCE. MOST OF THE GLOBAL MODELS SHOW A DECREASE IN SHEAR BEYOND THREE DAYS...BUT THERE MIGHT NOT BE MUCH LEFT BY THEN AND I'D PREFER TO SHOW LITTLE CHANGE FROM THE PREVIOUS FORECAST FOR NOW. THE INITIAL MOTION ESTIMATE IS A RATHER UNCERTAIN 275/10. A WEST OR WEST-NORTHWEST TRACK IS LIKELY FOR THE NEXT SEVERAL DAYS DUE TO RIDGING OVER THE EASTERN ATLANTIC. IF JOSEPHINE BECAME A STRONGER SYSTEM...IT WOULD PROBABLY MOVE MORE TOWARD THE NORTHWEST WITH A DEEPER STEERING CURRENT LIKE THE HWRF/GFDL MODELS SHOW. HOWEVER... I'M GOING TO STAY WITH THE PREVIOUS REASONING OF THE SYSTEM REMAINING WEAKER AND BEING STEERED BY THE MORE SHALLOW CURRENTS TOWARD THE WEST-NORTHWEST. THE OFFICIAL FORECAST IS ON THE SOUTHERN SIDE OF THE GUIDANCE ENVELOPE AND A LITTLE SOUTH OF THE PREVIOUS ONE...NOT TOO DISSIMILAR FROM THE FSU SUPERENSEMBLE. FORECAST POSITIONS AND MAX WINDS INITIAL 04/0300Z 13.9N 30.7W 45 KT 12HR VT 04/1200Z 14.2N 32.5W 45 KT 24HR VT 05/0000Z 14.6N 34.9W 40 KT 36HR VT 05/1200Z 15.0N 37.2W 40 KT 48HR VT 06/0000Z 15.5N 39.5W 35 KT 72HR VT 07/0000Z 17.0N 44.0W 30 KT 96HR VT 08/0000Z 18.5N 48.0W 30 KT 120HR VT 09/0000Z 21.5N 53.0W 30 KT $$ FORECASTER BLAKE |
