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| #38047 (Received by flhurricane at: 10:31 PM 06.Aug.2005) TCDAT4 TROPICAL DEPRESSION NINE DISCUSSION NUMBER 10 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT SAT AUG 06 2005 THE DEPRESSION CONTINUES TO BE STRONGLY SHEARED. THERE IS A WELL-DEFINED LOW-LEVEL CIRCULATION AND MOST OF THE CONVECTION IS TO THE EAST OF THE CENTER. DVORAK CLASSIFICATIONS CAN HARDLY SUPPORT A T-NUMBER BY USING THE DISTANCE BETWEEN THE CENTER AND THE CONVECTION. INITIAL INTENSITY IS KEPT AT 30 KNOTS. IT IS DIFFICULT TO VISUALIZE HOW THE CYCLONE WILL SURVIVE WITH THE CURRENT SHEAR CAUSED BY THE AMPLIFYING UPPER-LOW TO ITS NORTH. THE ATLANTIC IS PLAGUED WITH UPPER-LOWS...A PATTERN THAT IS UNFAVORABLE FOR TROPICAL CYCLONES TO INTENSIFY. THE GFS IS KEEPING THE UNFAVORABLE UPPER-LEVEL WINDS NEAR THE CYCLONE FOR DAYS...AND BOTH THE GFS AND THE GFDL RELENTLESSLY INSIST ON DISSIPATING THE CYCLONE. IT IS HARD TO GO AGAINST THESE TWO MODELS. HOWEVER...CONTINUITY FROM PREVIOUS FORECASTS WILL BE FOLLOWED...AND THE OFFICIAL FORECAST CALLS FOR SOME STRENGTHENING BY THE END OF THE PERIOD. THIS IS BASED ON THE OTHER GLOBAL MODELS WHICH HAVE A LESS HOSTILE ENVIRONMENT ALONG WITH THE SHIPS MODEL GUIDANCE. THE CENTER HAS BEEN MOVING WESTWARD ABOUT 9 KNOTS DURING THE PAST FEW HOURS. HOWEVER...MOST OF THE GUIDANCE IS IN FAIRLY GOOD AGREEMENT MOVING THE CYCLONE TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 9 KNOTS DURING THE NEXT 2 TO 3 DAYS. THEREAFTER...THE UK...THE ECMWF AND THE CANADIAN MODELS PREFER A SOUTHERNMOST TRACK AND THE NOGAPS A NORTHERMOST. THE GFS AND GFDL ARE NOT INCLUDED SINCE THEY DISSIPATE THE CYCLONE QUITE SOON. THE OFFICIAL FORECAST TRACK IS IN THE MIDDLE OF THE GUIDANCE ENVELOPE. THERE IS LOW CONFIDENCE IN THIS FORECAST BECAUSE IF THE SHEAR CONTINUES...THERE WILL BE NOTHING TO TRACK AS SUGGESTED BY GFS AND GFDL MODELS. FORECASTER AVILA FORECAST POSITIONS AND MAX WINDS INITIAL 07/0300Z 18.9N 44.3W 30 KT 12HR VT 07/1200Z 19.2N 45.6W 30 KT 24HR VT 08/0000Z 19.7N 47.6W 30 KT 36HR VT 08/1200Z 20.5N 49.5W 30 KT 48HR VT 09/0000Z 21.5N 51.0W 30 KT 72HR VT 10/0000Z 23.0N 54.5W 35 KT 96HR VT 11/0000Z 25.0N 57.0W 45 KT 120HR VT 12/0000Z 27.0N 59.5W 50 KT |
