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#935545 (Received by flhurricane at: 10:41 PM 08.Aug.2018) TCDAT4 Tropical Storm Debby Discussion Number 7 NWS National Hurricane Center Miami FL AL042018 1100 PM AST Wed Aug 08 2018 A very recent ASCAT pass indicates that Debby is stronger than previously estimated. The pass showed maximum winds of about 40 kt, and since the entire circulation was not captured, the initial intensity is set at 45 kt. This estimate is also in agreement with a Dvorak CI-number from TAFB. Although the relatively compact tropical storm is maintaining an area of moderate convection, the thunderstorm activity is displaced to the south-southwest of the center due to about 15 kt of wind shear. Debby is currently over fairly cool 25 deg C SSTs, but it will be headed for much cooler water during the next 24 to 36 hours. These unfavorable oceanic conditions combined with an increasingly stable airmass should cause weakening and extratropical transition. The NHC intensity forecast shows Debby becoming extratropical by 24 hours and dissipating shortly thereafter, following the GFS and ECMWF models. The tropical storm is moving northeastward, or 040 degrees, at 13 kt. A faster northeastward motion is expected until the cyclone opens into a trough as Debby becomes more embedded in the mid-latitude flow. The NHC track forecast lies near the middle of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 42.8N 46.5W 45 KT 50 MPH 12H 09/1200Z 44.4N 43.7W 40 KT 45 MPH 24H 10/0000Z 46.8N 37.7W 35 KT 40 MPH...POST-TROP/EXTRATROP 36H 10/1200Z...DISSIPATED $$ Forecaster Cangialosi |