000
WTNT42 KNHC 312043
TCDAT2

HURRICANE GASTON DISCUSSION NUMBER  37
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072016
500 PM AST WED AUG 31 2016

The satellite presentation of Gaston has gradually decayed today,
with the eye becoming more ragged in infrared imagery.  The initial
intensity estimate is 90 kt based on a blend of the latest Dvorak
Final-T and CI numbers from TAFB and SAB.  Steady weakening is
expected during the next few days while SSTs decrease steadily along
the forecast track and the shear increases above 20 kt by 48 hours.
The new NHC intensity forecast has been adjusted downward and is
close to the latest intensity model consensus, and now shows Gaston
weakening to a tropical storm as it approaches the Azores on Friday.
Gaston should lose tropical characteristics by 72 hours and
dissipate by 96 hours as shown by the global models.

The initial motion estimate is 055/16, and Gaston is expected to
move east-northeastward to eastward in the mid-latitude westerlies
through dissipation.  The NHC track forecast is a little north of
the previous one and is along the middle of the guidance envelope
but faster than the TVCN consensus, trending toward the faster FSU
Superensemble.

Based on the new forecast, a tropical storm watch has been issued
for portions of the western and central Azores.

FORECAST POSITIONS AND MAX WINDS

INIT  31/2100Z 35.0N  46.9W   90 KT 105 MPH
 12H  01/0600Z 36.3N  44.0W   85 KT 100 MPH
 24H  01/1800Z 37.7N  39.5W   75 KT  85 MPH
 36H  02/0600Z 38.5N  34.8W   65 KT  75 MPH
 48H  02/1800Z 39.0N  30.8W   55 KT  65 MPH
 72H  03/1800Z 41.0N  25.0W   35 KT  40 MPH...POST-TROPICAL
 96H  04/1800Z...DISSIPATED

$$
Forecaster Brennan