| Remains no threat to land through 5 days: http://www.nhc.noaa.gov/refresh/graphics_at2+shtml/023341.shtml?5day#contents TROPICAL STORM GASTON DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 1100 PM AST MON AUG 22 2016 The convective organization of the tropical cyclone has continued to increase this evening. A couple of well-defined curved bands of convection now wrap more than halfway around the center and some cold cloud tops have recently developed near the center. As a result, subjective Dvorak T-numbers have increased to T2.5 and support upgrading the system to a 35-kt tropical storm. Gaston becomes the seventh tropical storm of the 2016 Atlantic hurricane season. Gaston is forecast to move over warm water and remain in a low wind shear environment during the next couple of days. These favorable conditions should allow for steady strengthening, and Gaston is forecast to become a hurricane in about 36 hours, which agrees with the majority of the intensity guidance. In about 3 days, the global models suggest that Gaston will be nearing an upper-level low over the central Atlantic that could cause an increase in southwesterly shear over the system. This should halt intensification, and the NHC forecast calls for little change in strength after 72 hours. The tropical storm is being steered west-northwestward to the south of deep-layer ridge over the eastern Atlantic. A west-northwestward motion with some decrease in forward speed is expected during the next day or so. After that time, a weakness in the subtropical ridge over the central Atlantic should cause Gaston to turn northwestward. The track guidance remains in very good agreement, and the NHC forecast is close to the various consensus models. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 12.6N 30.7W 35 KT 40 MPH 12H 23/1200Z 13.0N 33.1W 45 KT 50 MPH 24H 24/0000Z 14.0N 36.0W 55 KT 65 MPH 36H 24/1200Z 15.3N 38.6W 65 KT 75 MPH 48H 25/0000Z 17.1N 41.1W 75 KT 85 MPH 72H 26/0000Z 21.0N 46.0W 80 KT 90 MPH 96H 27/0000Z 25.0N 50.5W 75 KT 85 MPH 120H 28/0000Z 28.0N 53.5W 75 KT 85 MPH $$ Forecaster Brown |