000 AXNT20 KNHC 012359 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT THU SEP 01 2016 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... Hurricane Hermine is centered near 29.1N 84.8W at 02/0000 UTC or about 40 nm south-southeast of Apalachicola, Florida and about 90 nm west of Cedar Key, Florida moving north-northeast at 12 kt. Estimated minimum central pressure is 983 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Scattered moderate to strong convection is north of 27N east of 87W to inland over Florida. Scattered moderate with clusters of isolated strong convection covers the area east of a line from 27N86W to 24N88W then southeast to the western tip of Cuba including most of the Florida peninsula, west Cuba, and the Straits of Florida. See latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/ WTNT24KNHC for more details. Hurricane Gaston is centered near 38.3N 37.3W at 02/0000 UTC or about 405 nm west of Faial Island in the central Azores and about 480 Nm west of Lajes Air Base in the Azores moving east- northeast at 22 kt. Estimated minimum central pressure is 984 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Scattered moderate to isolated strong convection is within 75 nm of a line from 37N38W 39N38W to 41N36W. See latest NHC Forecast/ Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. ...TROPICAL WAVES... Tropical wave in the central Atlantic extends along 36W/37W from 9N-20N moving west near 20 kt over the past 24 hours. Wave coincides with a well defined global model, 700 mb trough and is embedded within a surge of deep moisture as seen on the Total Precipitable Water imagery. Small clusters of isolated moderate convection dot the area from 13N-17N between 39W-42W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 15N17W along 11N27W 11N39W to 10N43W where the ITCZ begins and continues along 10N52W to near 11N59W. Clusters of scattered moderate to isolated strong convection are from 5N- 11N east of 34W to the coast of west Africa and from 8N-11N between 40W-48W. ...DISCUSSION... GULF OF MEXICO... The primary concern again this evening is Hurricane Hermine. Hermine became a hurricane this afternoon at 01/1855 UTC based on information from the Air Force Hurricane Hunter Aircraft. Hurricane Hermina is moving across the northeast Gulf of Mexico. The activity over the east Gulf of Mexico is due to Hurricane Hermine. See Special Features above. A broad upper trough covers the east CONUS dipping south over the west Gulf with a surface trough extending from 25N87W to 22N95W. Scattered showers and isolated thunderstorms are within 45 nm of the surface trough. Isolated showers and thunderstorms dot the area from 23N-26N between 91W-97W. Scattered to numerous showers and isolated thunderstorms are across the Bay of Campeche south of 20N west of 93W. The forecast track for Hermine takes the system northeastward across the western Florida panhandle overnight tonight then tracks along the coastal plains of the Carolinas Friday night and Saturday. Winds and seas will decrease over the Gulf Friday through Saturday. CARIBBEAN SEA... The upper ridge associated with Hermine covers the Caribbean west of 79W with a second upper ridge anchored in the west Atlantic covering the east Caribbean east of 70W. Wedge between these upper ridges is an elongated upper low centered along the southwest coast of Haiti near 18N74W and extends south across the Caribbean to the coast of Colombia. The northerly upper level flow over the west Caribbean combined with the southerly surface flow is generating isolated showers and thunderstorms dotting the west Caribbean north of 15N west of 77W. A surface trough extends from the central Atlantic near 23N58W across the northern Leeward Islands to 16N63W generating isolated showers and possible isolated thunderstorms over the northern Leeward Islands north of 17N to Puerto Rico. A second surface trough is east of the Windward Islands along 60W from 10N-16N generating scattered showers and isolated thunderstorms from 10N-17N between 58W-63W. The surface trough east of the Windward Islands will move into the east Caribbean tonight then continue westward into the weekend. Fresh to strong trade winds are across the south-central Caribbean through Friday. A tropical wave will enter the east Caribbean late Saturday. ...HISPANIOLA... Currently skies are mostly clear across the island. An elongated upper low is centered along the southwest coast of Haiti near 18N74W and extends south across the Caribbean to the coast of Colombia. The upper low will continue to track westward becoming an open trough Friday night. The surface trough over the Leeward Islands will continue moving westward bringing moisture to the island Friday giving the island showers and thunderstorms Friday and Saturday. ATLANTIC OCEAN... Hurricane Gaston continues moving northeast toward the northern Azores Islands. See Special features above. Scattered to numerous showers and isolated thunderstorms generated by Hurricane Hermine are north of 26N west of 79W to inland over Florida and southeast Georgia. The upper trough over the east CONUS is moving into the northwest Atlantic supporting a weak surface trough that extends through 32N74W to 30N75W. An elongated upper trough is in the central Atlantic extending from an upper low east of the Lesser Antilles near 17N55W to 32N44W supporting a surface trough that extends from 23N58W to 16N63W. This surface trough is leading the edge of large area of Saharan dust and dry air that extends east to off the coast of Africa near 20W and is limiting shower activity associated with this surface trough as well as the tropical wave. A second surface trough is east of the Windward Islands along 60W from 10N-16N generating scattered showers and isolated thunderstorms from 10N-17N between 58W-63W. The remainder of the Atlantic is dominated by a surface ridge that is anchored by a 1028 mb high over the Azores and extends a ridge axis through 32N31W, south of Hurricane Gaston, to a 1022 mb high near 29N47W continuing along 28N60W then southwest to 24N77W. Hurricane Hermine is expected to track inland along the southeast CONUS Friday into Saturday morning before entering the northwest Atlantic later Saturday. Strong southerly winds and high seas will develop over the west Atlantic waters east of the northeast Florida through Friday before shifting northward. For additional information please visit http://www.hurricanes.gov/marine $$ PAW