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| #873561 (Received by flhurricane at: 11:20 PM 31.Aug.2016) TCDAT2 HURRICANE GASTON DISCUSSION NUMBER 38 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 1100 PM AST WED AUG 31 2016 Gaston's infrared satellite pattern has changed little since the previous advisory. The eye remains ragged but clear, and cold convective tops continue in all quadrants. Recent microwave imagery, however, does show that the southwestern eyewall is now open, and there are some indications that the circulation is becoming tilted due to west-southwesterly shear. Still, the initial intensity remains 90 kt based on a blend of final-T and CI numbers from TAFB and SAB, which is also supported by the latest CI estimate from the objective ADT. The hurricane is expected to be over sea surface temperatures warmer than 26C for another 12-18 hours while vertical shear is forecast to be at or above 20 kt for the next few days. Therefore, a gradual weakening trend is anticipated, and Gaston is forecast to lose hurricane intensity in about 36 hours while it approaches the western Azores. After that time, continued weakening is expected, and Gaston is likely to become a remnant low in about 72 hours after it has passed the Azores and loses its deep convection over very cold water. Dissipation is still expected by day 4. The intensity models are in very good agreement on the weakening trend, and the updated NHC forecast is close to the intensity consensus. The initial motion remains northeastward but a little faster at 055/17 kt. Gaston is embedded in the mid-latitude westerlies, and it is expected to turn east-northeastward and accelerate during the next 24 hours. After that time, Gaston could slow down a bit while it moves across the Azores, and then turn back toward the northeast when it becomes a remnant low. Like the intensity guidance, the track models are in very good agreement, and no significant changes were needed from the previous forecast. FORECAST POSITIONS AND MAX WINDS INIT 01/0300Z 36.0N 45.4W 90 KT 105 MPH 12H 01/1200Z 37.2N 42.1W 80 KT 90 MPH 24H 02/0000Z 38.2N 37.5W 70 KT 80 MPH 36H 02/1200Z 38.7N 33.3W 60 KT 70 MPH 48H 03/0000Z 39.2N 30.3W 45 KT 50 MPH 72H 04/0000Z 42.1N 24.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 05/0000Z...DISSIPATED $$ Forecaster Berg |
