|
Show Selection: |
| #146006 (Received by flhurricane at: 11:08 PM 14.Aug.2007) TCDAT4 TROPICAL STORM DEAN DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007 1100 PM EDT TUE AUG 14 2007 AFTER THE CONVECTION WANED THIS AFTERNOON...A NEW BURST HAS REDEVELOPED OVER THE CENTER DURING THE PAST FEW HOURS. DESPITE THE SOMEWHAT RAGGED SATELLITE APPEARANCE AROUND 2100 UTC...A QUIKSCAT PASS AT THAT TIME DETECTED A RATHER WELL DEFINED CIRCULATION WITH BELIEVABLE 45-50 KT WINDS. WITH A NOD TO THE SATELLITE PRESENTATION...THE INITIAL INTENSITY IS SET AT A POSSIBLY CONSERVATIVE 45 KT. RECENT MICROWAVE IMAGERY AND THE QUIKSCAT DATA SUGGEST THAT THE CENTER IS SLIGHTLY NORTH OF THE EARLIER ESTIMATES. THE INITIAL MOTION IS 270/16...A LITTLE SLOWER THAN THE PREVIOUS ADVISORY. THE FORECAST PHILOSOPHY REMAINS UNCHANGED AS DEAN IS EXPECTED TO BE STEERED WEST TO WEST-NORTHWESTWARD DURING THE NEXT FEW DAYS...SOUTH OF A DEEP-LAYER RIDGE. THE MODEL GUIDANCE GENERALLY AGREES ON THIS SCENARIO BUT WITH SOMEWHAT VARYING FORWARD SPEEDS. THE OFFICIAL TRACK FORECAST REMAINS FASTER THAN THE NOGAPS AND ECMWF SOLUTIONS...WHICH CONTINUE TO STRUGGLE INITIALIZING THE FORWARD MOTION OF DEAN. THE NEW TRACK FORECAST IS CLOSER TO THE CONSENSUS OF THE GFDL...HWRF AND GFS MODELS THROUGH 72 HOURS...BUT IS A LITTLE SLOWER THAN THESE MODELS AT DAYS 4 AND 5. IT APPEARS THAT THE EASTERLY SHEAR THAT HAS BEEN AFFECTING DEAN IS BEGINNING TO DECREASE. THE GLOBAL MODELS FORECAST A FAVORABLE ENVIRONMENT FOR STEADY STRENGTHENING AND THE AVAILABLE INTENSITY GUIDANCE BRINGS DEAN TO A HURRICANE IN 36-48 HOURS...AND NEAR THE MAJOR HURRICANE THRESHOLD BY DAY 5. THE WIND RADII WERE ADJUSTED BASED ON THE QUIKSCAT DATA. FORECAST POSITIONS AND MAX WINDS INITIAL 15/0300Z 12.0N 42.3W 45 KT 12HR VT 15/1200Z 12.2N 44.8W 50 KT 24HR VT 16/0000Z 12.4N 48.2W 55 KT 36HR VT 16/1200Z 12.8N 51.7W 60 KT 48HR VT 17/0000Z 13.4N 55.2W 70 KT 72HR VT 18/0000Z 14.5N 61.0W 80 KT 96HR VT 19/0000Z 16.0N 66.5W 90 KT 120HR VT 20/0000Z 17.5N 71.5W 100 KT $$ FORECASTER BROWN |
