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| #47532 (Received by flhurricane at: 4:37 PM 21.Sep.2005) TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 18 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT WED SEP 21 2005 THE CENTER OF PHILIPPE REMAINS EXPOSED WELL TO THE WEST OF THE DEEP CONVECTION. PHILIPPE CONTINUES TO WEAKEN AS DVORAK DATA T NUMBERS CONTINUE TO DECREASE. THE INITIAL INTENSITY WILL BE LOWERED TO 40 KT FOR THIS ADVISORY. THE INITIAL MOTION IS A LITTLE FASTER AND IS ESTIMATED TO BE 360/8. THE TRACK FORECAST WAS ADJUSTED A LITTLE EASTWARD BASED ON THE MORE NORTHWARD CURRENT MOTION. THE OVERALL FORECAST REASONING REMAINS THE SAME THROUGH 72 HOURS. IN THE LONGER RANGE...THE GFS IS NOW THE ONLY MODEL THAT SUGGESTS THAT PHILIPPE WILL NOT GET PICKED UP BY A LARGE EXTRATROPICAL CYCLONE OVER THE NORTH ATLANTIC...AND THIS IS DISCOUNTED AT THIS TIME. THE REMAINDER OF THE MODEL GUIDANCE INDICATES THAT THE CYCLONE WILL ACCELERATE NORTHEASTWARD AND INTERACT WITH A FRONTAL ZONE...BECOMING EXTRATROPICAL BY 120 HOURS. HOWEVER...THE OFFICIAL FORECAST IS NOT AS FAST THE GFDL AND UKMET SOLUTIONS. THE OFFICIAL FORECAST INDICATES THAT PHILIPPE WILL BECOME EXTRATROPICAL IN 120 HOURS...BUT IT MAY HAPPEN SOONER. THE INTENSITY FORECAST REMAINS PROBLEMATIC. SINCE THE SHEAR IS NOT FORECAST TO DECREASE MUCH...ONE WOULD THINK THAT PHILIPPE WOULD REMAIN STEADY STATE OR CONTINUE TO WEAKEN. HOWEVER...THE FUTURE INTERACTION BETWEEN PHILLIPE AND THE UPPER LOW NEAR 22N62W COULD TRANSITION THE TROPICAL CYCLONE INTO MORE OF A HYBRID SYSTEM. THEREFORE...THE INTENSITY FORECAST CALLS FOR MODEST STRENGTHENING IN 24-36 HOUR WITH AN EXPANDED WIND FIELD TO THE NORTHEAST. LATER IN THE FORECAST THE SHEAR BECOMES MUCH STRONGER AND THE CYCLONE SHOULD WEAKEN BEFORE BECOMING FINALLY BECOMING EXTRATROPICAL. FORECASTER BROWN/FRANKLIN FORECAST POSITIONS AND MAX WINDS INITIAL 21/2100Z 21.2N 57.1W 40 KT 12HR VT 22/0600Z 22.8N 57.3W 40 KT 24HR VT 22/1800Z 25.3N 57.9W 45 KT 36HR VT 23/0600Z 27.8N 58.4W 50 KT 48HR VT 23/1800Z 30.5N 59.0W 50 KT 72HR VT 24/1800Z 35.0N 56.5W 45 KT 96HR VT 25/1800Z 38.5N 49.0W 40 KT 120HR VT 26/1800Z 42.5N 41.5W 40 KT...EXTRATROPICAL |
