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| #305968 (Received by flhurricane at: 9:58 AM 04.Nov.2009) TCDAT1 TROPICAL DEPRESSION ELEVEN DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112009 1000 AM EST WED NOV 04 2009 THE AREA OF LOW PRESSURE IN THE SOUTHWESTERN CARIBBEAN SEA HAS DEVELOPED ENOUGH ORGANIZED THUNDERSTORM ACTIVITY TO NOW BE CONSIDERED A TROPICAL DEPRESSION. SATELLITE IMAGES SHOW THAT A NEW BURST OF THUNDERSTORMS IS OCCURRING NEAR THE CENTER WITH BANDING FEATURES BECOMING MORE DISTINGUISHED. TAFB/SAB DVORAK CLASSIFICATIONS WERE 2.0...30 KT...AT 1200 UTC...AND THAT INTENSITY WILL BE USED AS THE INITIAL WIND SPEED. IT WOULD NOT BE SURPRISING...HOWEVER...IF THIS SYSTEM WERE ALREADY A TROPICAL STORM DUE TO THE IMPROVING SATELLITE PRESENTATION. THE AIR FORCE RESERVE WILL BE IN THE AREA THIS AFTERNOON TO GIVE A BETTER ESTIMATE OF THE WINDS. THE INITIAL MOTION USED FOR THIS ADVISORY IS 315/7...THOUGH IT IS UNCERTAIN WHETHER THIS IS TRULY REPRESENTATIVE DUE TO THE CENTER REFORMATION THAT APPEARED TO OCCUR OVERNIGHT. STEERING CURRENTS ARE EXPECTED TO BE FAIRLY LIGHT DURING THE NEXT SEVERAL DAYS AS THE DEPRESSION IS CAUGHT BETWEEN A WEAK MID-LEVEL HIGH OVER THE NORTH-CENTRAL CARIBBEAN SEA AND A TROUGH OVER THE SOUTHWESTERN GULF OF MEXICO. ALTHOUGH THERE IS GENERAL AGREEMENT IN THE LARGE-SCALE PATTERN...THE MODELS ARE SHOWING A LARGE AMOUNT OF DIVERGENCE ON THE EXPECTED PATH OF THE DEPRESSION. MOST OF THE GUIDANCE SUGGEST THE SYSTEM WILL MOVE TO THE NORTHWEST THEN NORTH AROUND THE SOUTHWESTERN PERIPHERY OF THE CARIBBEAN RIDGE. HOWEVER...SOME OF THE RELIABLE GUIDANCE...SUCH AS THE ECMWF AND UKMET...SHOW THE SYSTEM MOVING CONSIDERABLY SLOWER WITH ONLY A NORTHWARD DRIFT. GIVEN THE UNCERTAINTY...THE NHC FORECAST IS NEAR BUT SLIGHTLY TO THE RIGHT OF THE MODEL CONSENSUS. ALTHOUGH THE DEPRESSION IS CURRENTLY IN A LIGHT SHEAR AND WARM WATER ENVIRONMENT...ITS PROXIMITY TO LAND AND UNCERTAIN TRACK FORECAST LEADS TO A COMPLEX INTENSITY FORECAST. THE GFDL...ONE OF THE ONLY MODELS THAT KEEPS THE SYSTEM OFFSHORE...MAKES THE SYSTEM A HURRICANE IN A FEW DAYS. HOWEVER...NEITHER THE SHIPS NOR THE LGEM MODELS SHOW MUCH INTENSIFICATION AT ALL. THESE MODELS SEEM TO BE A LITTLE UNDERDONE...AND THE NHC FORECAST WILL BE ON THE HIGHER SIDE OF THE GUIDANCE ENVELOPE...THOUGH NOT AS HIGH AS THE GFDL. FORECAST POSITIONS AND MAX WINDS INITIAL 04/1500Z 11.6N 82.0W 30 KT 12HR VT 05/0000Z 11.9N 82.3W 45 KT 24HR VT 05/1200Z 12.5N 83.0W 50 KT 36HR VT 06/0000Z 13.0N 83.5W 50 KT 48HR VT 06/1200Z 13.5N 84.0W 35 KT...INLAND 72HR VT 07/1200Z 14.5N 84.5W 25 KT...INLAND 96HR VT 08/1200Z 15.5N 85.0W 25 KT...INLAND 120HR VT 09/1200Z 18.0N 85.5W 35 KT...OVER WATER $$ FORECASTER BLAKE/FRANKLIN |
