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#32099 (Received by flhurricane at: 10:43 AM 11.Jul.2005) TCDAT5 TROPICAL DEPRESSION FIVE DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT MON JUL 11 2005 VISIBLE IMAGERY REVEALS THAT THE DEPRESSION IS NOT WELL ORGANIZED... WITH A LOW-LEVEL CIRCULATION LOCATED ALONG THE EASTERN EDGE OF THE DEEP CONVECTION...ABOUT 80 NM TO THE EAST OF THE MID-LEVEL TURNING. A QUIKSCAT PASS AT 09Z SUGGESTED THAT THIS SMALL LOW-LEVEL CIRCULATION MAY MERELY BE A SWIRL EMBEDDED WITHIN AN ILL-DEFINED BROADER LOW. IMPROVED BANDING FEATURES TO THE SOUTHWEST OVER THE PAST FEW HOURS ALSO SUGGEST THAT IT IS THE BROADER LOW THAT MAY ULTIMATELY PREVAIL. RATHER THAN JERK THE TRACK BACK TO THE EAST TO FOLLOW THE SWIRL...I PREFER TO FOLLOW THE BROADER SYSTEM AT THIS TIME. THE POOR ORGANIZATION OF THE SYSTEM...AND DVORAK CLASSIFICATIONS FROM TAFB AND SAB OF T2.0...ARE GOOD REASONS NOT TO UPGRADE THE DEPRESSION TO A TROPICAL STORM. WHILE THERE IS PRESENTLY SOME EASTERLY SHEAR WITH THIS SYSTEM...AS WELL AS MARGINAL THERMODYNAMICS...THE ENVIRONMENT IS EXPECTED TO BECOME MORE FAVORABLE FOR DEVELOPMENT IN BOTH REGARDS OVER THE NEXT FEW DAYS. GIVEN THIS...SLOW BUT STEADY STRENGTHENING IS ANTICIPATED OVER THE NEXT 72 HOURS...AND THE OFFICIAL FORECAST IS IN GOOD AGREEMENT WITH SHIPS AND GFDL GUIDANCE. THE GFDL...WHICH DEVELOPS THE DEPRESSION ONLY SLOWLY AT FIRST...CONTINUES TO MAKE THE CYCLONE A SIGNIFICANT HURRICANE IN THE CARIBBEAN. THE INITIAL MOTION ESTIMATE CONTINUES TO BE 270/10. SOME INCREASE IN FORWARD SPEED IS ANTICIPATED AS THE CYCLONE MOVES AWAY FROM THE INFLUENCE OF BROAD CYCLONIC FLOW OVER THE EASTERN ATLANTIC AND BECOMES MORE EMBEDDED IN A DEEP EASTERLY STEERING CURRENT. THE OFFICIAL FORECAST...WHICH IS A LITTLE SOUTH OF THE PREVIOUS FORECAST...IS A BLEND OF THE GFDL AND NOGAPS MODELS. IT IS PERHAPS OF INTEREST TO NOTE THAT THE NOGAPS...WHICH HAD ONLY A SO-SO YEAR LAST YEAR...IS CURRENTLY THE BEST PERFORMING ATLANTIC TRACK MODEL SO FAR IN 2005...AND THE FSU SUPERENSEMBLE...WHICH WON HANDS DOWN LAST YEAR...IS STRUGGLING A BIT. FORECASTER FRANKLIN FORECAST POSITIONS AND MAX WINDS INITIAL 11/1500Z 10.3N 44.7W 30 KT 12HR VT 12/0000Z 10.4N 46.3W 35 KT 24HR VT 12/1200Z 10.8N 48.9W 40 KT 36HR VT 13/0000Z 11.5N 52.0W 45 KT 48HR VT 13/1200Z 12.2N 55.2W 50 KT 72HR VT 14/1200Z 14.0N 61.0W 60 KT 96HR VT 15/1200Z 16.5N 67.0W 70 KT 120HR VT 16/1200Z 19.0N 73.0W 70 KT |