190 
WTNT44 KNHC 090241
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