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| #37055 (Received by flhurricane at: 5:52 PM 02.Aug.2005) TCDAT3 TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT TUE AUG 02 2005 WHILE THE CIRCULATION CENTER IS PERHAPS NOT REAL WELL DEFINED IN SATELLITE IMAGERY...THE IMAGERY DOES SHOW A NUMBER OF SMALL SWIRLS ROTATING AROUND A COMMON CENTER. THIS IS ALSO NOT THE MOST TROPICAL OF TROPICAL CYCLONES. HOWEVER...THE CENTER IS CLOSE ENOUGH TO THE DEEP CONVECTION...WITHIN 60 NMI...AND THE UPPER LOW TO THE SOUTHWEST IS FAR ENOUGH AWAY TO CONSIDER THIS SYSTEM MORE TROPICAL THAN SUBTROPICAL. THE DEPRESSION ALSO LIES SLIGHTLY ON THE SYMMETRIC WARM CORE SIDE OF BOB HART'S FSU CYCLONE PHASE SPACE ANALYSIS DIAGRAMS. THE INITIAL INTENSITY IS SET TO 30 KT BASED ON EARLIER SHIP REPORTS OF 25 KT THAT WERE OUTSIDE OF THE DEEP CONVECTION. THE INITIAL MOTION IS ESTIMATED TO BE 010/11. THE DEPRESSION IS LOCATED TO THE NORTHEAST OF AN UPPER-LEVEL LOW THAT IS DISPLACING THE CONVECTION TO THE NORTH AND NORTHEAST OF THE CENTER. THIS ASYMMETRY MAY CONTRIBUTE TO SOME REFORMATION OR APPARENT MOTION OF THE CENTER NORTHEASTWARD. THERE ARE A COUPLE OF WEAK 500 MB SHORT-WAVE TROUGHS IN THE WESTERLIES THAT SHOULD HELP TO NUDGE THE CYCLONE NORTHEASTWARD OVER THE NEXT COUPLE OF DAYS. MODEL GUIDANCE IS IN RATHER POOR AGREEMENT AND OF LIMITED HELP. THE GFS DEVELOPS A POSSIBLY SPURIOUS SECOND LOW CLOSE TO THE DEPRESSION THAT COMPLICATES INTERPRETATION OF ITS FORECAST TRACK. THE UKMET APPEARS TO BE INITIALIZED TOO FAR TO THE SOUTH AND THE NOGAPS TOO FAR TO THE WEST. THE OFFICIAL FORECAST IS PRIMARILY A BLEND OF THE GFDL AND MEDIUM BAM MODELS. THE TREND TODAY HAS BEEN FOR THE CIRCULATION CENTER AND DEEP CONVECTION TO BECOME SOMEWHAT BETTER ALIGNED...AND IF THE CYCLONE CAN GET A LITTLE FARTHER AWAY FROM THE UPPER LOW IT WOULD BE IN A MORE FAVORABLE ENVIRONMENT FOR STRENGTHENING. GLOBAL MODELS INDICATE THAT THIS UPPER LOW IS GOING TO SLIDE EASTWARD AND FOLLOW THE CYCLONE. IF THIS HAPPENS...VERTICAL WIND SHEAR COULD INCREASE AGAIN. THE OFFICIAL FORECAST ALLOWS FOR A MODEST WINDOW OF OPPORTUNITY FOR SOME STRENGTHENING. IF THE DEPRESSION BECOMES A TROPICAL STORM AS FORECAST...IT WOULD BE THE EARLIEST 8TH TROPICAL STORM ON RECORD. THE CURRENT RECORD IS AUGUST 15TH. FORECASTER FRANKLIN FORECAST POSITIONS AND MAX WINDS INITIAL 02/2100Z 28.5N 68.7W 30 KT 12HR VT 03/0600Z 30.3N 68.3W 40 KT 24HR VT 03/1800Z 32.0N 66.7W 45 KT 36HR VT 04/0600Z 33.3N 64.7W 45 KT 48HR VT 04/1800Z 33.8N 62.2W 40 KT 72HR VT 05/1800Z 34.0N 57.0W 35 KT 96HR VT 06/1800Z 34.5N 54.0W 30 KT 120HR VT 07/1800Z 35.0N 52.0W 30 KT |
