000 AXNT20 KNHC 030005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT FRI SEP 2 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... Tropical Storm Hermine is centered near 33.5N 79.5W at 03/0000 UTC or about 30 nm west-southwest of Myrtle Beach, South Carolina and about 45 nm northeast of Charleston, South Carolina moving northeast at 17 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate convection is from 31N to 37W between 72W and 82W. Locally heavy rainfall and flooding is possible in the path of this storm. Please see the 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. Tropical Storm Gaston is centered near 39.6N 29.8W at 03/0000 UTC or about 75 nm northwest of Faial Island in the central Azores and about 135 nm west-northwest of Lajes Air Base in the Azores moving east- northeast at 14 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. No deep convection is noted with this system. Please see the latest NHC Forecast/ Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. ...TROPICAL WAVES... A tropical wave is over the eastern Atlantic with an axis along 24W/25W, through a 1010 mb low near 16N25W. The northern portion of this wave is interacting with African dust which is inhibiting convection. Isolated moderate convection is from 06N to 14N between 22W and 28W. A tropical wave is moving across the central Atlantic along 46W, through a 1010 mb low near 13N46W. This wave is embedded in a moderately moist environment with upper level diffluence supporting scattered moderate convection from 12N to 18N between 43W and 54W. This wave is also generating a broad area of fresh to strong easterly winds across the northern portion of the wave. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 14N17W to 10N25W to 11N35W to 09N45W. Other than convection associated with the tropical waves, scattered moderate and isolated strong convection are from 05N to 12N between 28W and 40W. ...DISCUSSION... GULF OF MEXICO... Winds and seas over the eastern Gulf have been gradually improving through the day today as Tropical Storm Hermine moves northeast of the region. A trailing surface trough from Hermine extends from northern Florida to 27N90W to 24N93W. SW winds of 15 to 25 kt are south of this trough, and east of 86W to the Florida coast. A diffluent upper level environment and abundant moisture to the south of the trough support scattered to numerous showers and thunderstorms from 23N to near the trough axis. Another surface trough is over the southwestern Gulf with an axis from 23N94W to 18N94W. Scattered showers and thunderstorms are south of 25N west of 92W. Elsewhere over the Gulf, moderate to fresh northwest winds are occurring over the extreme northwest Gulf, and moderate northwesterly winds are north of the trough over the northeastern Gulf. Moderate northeasterly winds are west of the trough, and light to gentle winds are east of the trough over the southwestern Gulf. Over the next 24 hours the trough supporting showers and thunderstorms over the eastern Gulf will remain nearly stationary. The trough over the southwestern Gulf will drift toward the Mexico coast with ongoing showers and thunderstorms. CARIBBEAN SEA... An upper level low over the western Caribbean near 19N80W is supporting isolated thunderstorms over the western Caribbean this evening. A weak surface trough extending from 17N69W to 13N70W supports isolated showers and thunderstorms within 210 nm of either side of the trough axis. Moderate to locally fresh trade winds dominate the Caribbean this evening. Over the next 24 hours the trough will move west over the central Caribbean, helping to bring an increase in trades over the south central Caribbean Saturday night. A strong tropical wave will reach the eastern Caribbean Saturday night to Sunday with showers and thunderstorms. Fresh to strong easterly winds will accompany the northern portion of this wave. ...HISPANIOLA... The southern portion of a surface trough extending into the Atlantic supports scattered showers and thunderstorms this evening across the island. Dry conditions will return overnight. A strong tropical wave will bring increasing easterly winds along with showers and thunderstorms to the area beginning late Sunday. ATLANTIC OCEAN... Tropical Storm Gaston is rapidly weakening as it nears the Azores. Tropical Storm Hermine is just inland over the Carolinas this evening. Strong to near gale southwesterly winds are north of 27.5N west of 76W as well as seas to 14 feet. Scattered squalls and isolated thunderstorms are north of 27N west of 77W. See the Special features above for details on these two storms. A surface trough extends from Hispaniola to 23N68W. Scattered showers and isolated thunderstorms are within 210 nm north and west of the trough axis. Two tropical waves are moving across the basin. Please refer to the tropical waves section above for details. A surface ridge prevails across the remainder of the basin anchored by a 1023 mb high near 29N48N and a 1023 mb high near 33N27W. Over the next 24 hours Tropical Storm Hermine will track northeastward north of our area. However, fresh to strong winds, large seas, and scattered squalls will continue along the extreme northwestern portion of our discussion waters over the weekend. The westernmost tropical wave will continue to produce showers and thunderstorms as it moves westward across the remainder of the central tropical Atlantic through Saturday night. For additional information please visit http://www.hurricanes.gov/marine $$ LATTO