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| #873217 (Received by flhurricane at: 10:53 PM 28.Aug.2016) TCDAT2 HURRICANE GASTON DISCUSSION NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 1100 PM AST SUN AUG 28 2016 Gaston remains a well organized hurricane. Satellite images indicate that the eye remains quite distinct with a symmetric ring of deep convection around it. The upper-level outflow is well established both to the west and the east of the system. The latest Dvorak classifications from TAFB and SAB are 5.5/102 kt, and automated values from CIMSS at the University of Wisconsin are 5.9/112 kt. Based on these data, the initial wind speed is nudged upward to 105 kt. Gaston has not moved very little during the last several hours. A continued slow and likely erratic northward motion is forecast overnight and Monday while Gaston remains in weak steering currents caused by a blocking mid-level ridge to its northwest. A trough that is currently over eastern Canada is expected to dampen by the time it nears Gaston, but it should be strong enough to erode the ridge and allow the hurricane to become embedded in the mid-latitude westerlies. This pattern change should result in Gaston's turning east-northeastward in about 24 hours, with the cyclone continuing in that direction through the remainder of the forecast period. The model guidance remains tightly packed, and little change was made to the previous NHC track prediction. The atmospheric conditions suggest that Gaston could maintain its strength for the next day or so, however, given the expected slow motion of the cyclone there is some chance that cold water upwelling would counteract that. Beyond that time, the hurricane is likely to encounter an environment of increasing shear, drier air, and cooler water. Given these expected conditions, the NHC intensity forecast shows a gradual weakening trend beginning on Monday. This prediction is in best agreement with the SHIPS guidance. FORECAST POSITIONS AND MAX WINDS INIT 29/0300Z 30.6N 55.2W 105 KT 120 MPH 12H 29/1200Z 30.9N 55.4W 105 KT 120 MPH 24H 30/0000Z 31.4N 54.9W 100 KT 115 MPH 36H 30/1200Z 32.1N 53.5W 95 KT 110 MPH 48H 31/0000Z 33.0N 51.5W 95 KT 110 MPH 72H 01/0000Z 35.5N 46.0W 90 KT 105 MPH 96H 02/0000Z 37.4N 38.7W 75 KT 85 MPH 120H 03/0000Z 37.7N 33.0W 60 KT 70 MPH $$ Forecaster Cangialosi |
