000 AXNT20 KNHC 010007 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT WED AUG 31 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 Gaston is centered near 35.6N 46.5W at 01/0000 UTC or about 870 nm west of Faial Island in the central Azores and about 950 nm west of Lajes Air Base in the Azores moving northeast at 16 kt. Estimated minimum central pressure is 969 mb. Maximum sustained wind speed is 90 kt with gusts to 110 kt. Scattered moderate to isolated strong convection is within 150 nm of the center in all quadrants. See latest NHC Forecast/ Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. Tropical Storm Hermine is centered near 25.5N 87.4W at 01/0000 UTC or about 290 nm south-southwest of Apalachicola, Florida and about 290 nm southwest of Tampa, Florida moving north-northeast at 7 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered to numerous strong convection is within 30/45 nm of a line from 25N87W to 23N89W. Scattered moderate to isolated strong convection covers the Gulf east of a line from Apalachicola, Florida along 26N89W to 19N93W including portions of Florida, Cuba and the Yucatan peninsula. See latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. Tropical Depression Eight is centered near 36.3N 71.9W at 31/2100 UTC or about 185 nm east-northeast of Cape Hatteras North Carolina and 1050 nm west-southwest of Cape Race Newfoundland moving northeast at 14 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Scattered moderate convection is sheared to the northeast of the center, from 35N-37N between 70W-71W. See latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT3/WTNT33 KNHC and the full Forecast/Advisory under the AWIPS/WMO headers MIATCMAT3/WTNT23 KNHC for more details. ...TROPICAL WAVES... Tropical wave in the east Atlantic extends along 29W from 10N- 20N with a 1012 mb low along the wave near 13N29W. Wave and low are moving west 10 to 15 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. Scattered moderate to isolated strong convection is within 90 nm of the low over the northwest quadrant. Tropical wave in the central Atlantic extends along 43W/44W from 8N-19N moving west at 15 to 20 kt over the past 24 hours. Wave is embedded within a weak surge of moisture as seen on the Total Precipitable Water imagery. No associated showers or deep convection. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 21N17W through the 1012 mb low along the wave near 13N29W 8N35W to 7N41W where the ITCZ begins and continues along 10N55W to South America near 9N61W. Scattered moderate to strong convection is inland over west Africa from Guinea to Mauritania and within 90 nm along the coast from 7N-11N and 75 nm along the coast from 16N-21N. Clusters of scattered moderate to isolated strong convection are within 120 nm south of the ITCZ between 47W-57W and within 210 nm north of the ITCZ between 48W-56W. ...DISCUSSION... GULF OF MEXICO... The primary concern this evening is Tropical Storm Hermine moving through the Gulf of Mexico. See Special features above. An upper low is in the west Gulf near 25N93W while an upper ridge is over Mexico anchored near 24N103W. This is creating a diffluent environment along the west Gulf coast to generate scattered showers and isolated thunderstorms from 23N-27N west of 95W. A large upper ridge covers the remainder of the Gulf as well as the activity in the east Gulf being associated with Tropical Storm Hermine. The current forecast track takes Tropical Storm Hermina across the Florida panhandle near the Big Bend Region late Thursday night then continues northeast inland along the coastal plains of Georgia and the Carolinas. CARIBBEAN SEA... The upper ridge associated with Hermine covers the Caribbean west of 75W with a second upper ridge anchored in the central Atlantic covering the east Caribbean east of 67W. Wedge between these upper ridges is an elongated upper low centered along the north coast of Hispaniola near 20N71W and extends south into the Caribbean waters. 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 14N west of 76W. The upper low is generating scattered showers and isolated thunderstorms inland over Hispaniola west of 71W. The easterly trade winds over the east Caribbean are generating isolated showers and possible isolates thunderstorms from 12N-16N east of 67W to over the Lesser Antilles. Fresh to strong trade winds are across the south-central Caribbean through Friday. ...HISPANIOLA... An upper low remains along the north coast of Hispaniola near 20N71W with scattered showers and isolated thunderstorms west of 71W. The upper low will track westward becoming an open trough through Friday. Afternoon/evening showers and thunderstorms could develop across the island through Friday. ATLANTIC OCEAN... Hurricane Gaston moving through the north-central Atlantic and Tropical Depression Eight moving off the coast of North Carolina are the primary concerns for the Atlantic basin this evening. See Special features above. Scattered to numerous showers and isolated thunderstorms are northwest of a line from West Palm Beach Florida to beyond 32N74W due to the outflow from Tropical Storm Hermine in the Gulf of Mexico. An elongated upper trough is in the east-central Atlantic extending from 15N55W to 32N4! supporting a surface trough that extends from 22N52W to 16N53W. This surface trough is along the leading edge of large area of of Saharan dust and dry air that extends east to the coast of Africa. this is limiting shower activity associated with this surface trough as well as the two tropical waves. The remainder of the Atlantic is dominated by a surface ridge that is anchored by a 1028 mb high just south of the Azores and extends a ridge axis through 32N35W south of Hurricane Gaston along 26N48W to a 1019 mb high near 25N61W continuing to 28N76W. Tropical Storm Hermine is expected to track inland along the southeast CONUS Friday and Saturday. This will generate strong southerly winds off the northeast Florida coast with seas building to 10 ft Thursday and Friday. For additional information please visit http://www.hurricanes.gov/marine $$ PAW