000 AXNT20 KNHC 301049 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 649 AM EDT TUE AUG 30 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 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...SPECIAL FEATURES... Hurricane Gaston is centered near 32.0N 54.0W at 30/0900 UTC or about 550 nm east of Bermuda and about 1370 nm west of the Azores moving northeast at 5 kt. Estimated minimum central pressure is 971 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Scattered to numerous moderate convection is from 29N-34N between 51W-56W. See latest NHC Forecast/Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. Tropical Depression Eight is centered near 33.9N 75.0W at 30/0900 UTC or about 80 nm southeast of Cape Hatteras North Carolina moving northwest at 5 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is observed from 32N-35N between 72W and 75W. 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 Depression Nine is centered near 23.8N 86.6W at 30/0900 UTC or about 270 nm west of Key West Florida and about 235 nm west-northwest of Havana Cuba moving west at 6 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Numerous strong convection is observed from 21N-26N between 84W-87W. See latest NHC Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...TROPICAL WAVES... A tropical wave is analyzed from 09N35W to 18N35W moving west at 15 to 20 kt. The tropical wave is well represented on animated precipitable water imagery and GOES high density winds for the lower and mid levels of the atmosphere. Aside from mid level cloudiness, no significant sensible weather is associated with this tropical wave and minimal amplification at the surface. Global models indicate the tropical wave will continue west although remain fairly weak at the surface, possible bringing a few showers into the Leeward and Windward Islands by Thursday. A tropical wave emerging off the African coast reaches from 08N19W to 1008 mb low pressure near 16N20W to 18N19W. The gradient bewteen the tropical wave and high pressure to the north is enhancing northeast flow across the Canary Islands. Scattered moderate showers and thunderstorms are evident off the coast of Senegal, Gambia and Guinea-Bissau. The tropical wave is expected to stay intact as it tracks westward across the Atlantic over the next several days, accompanied by areas of fresh to strong winds and scattered showers and thunderstorms. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 09N21W to 08N27W to 09N40W. The intertropical convergence zone axis extends from 09N40W to 06N57W. Scattered moderate convection is evident within 120 nm south of the monsoon trough and ITCZ axes between 25W and 45W, and within 180 nm north of the ITCZ between 25N and 55W. ...DISCUSSION... GULF OF MEXICO... The primary concern is Tropical Depression Nine centered in the southeast Gulf under an upper level anticyclonic circulation allowing slow and gradual strengthening during the next several days. A weak trough remains in place over the northwest Gulf reaching from a 1010 mb low pressure system centered near 27N97W to 27N92W. Moderate to fresh northeast to east winds are noted north of the trough axis and west of 90W. Convergence of these winds is supporting scattered showers and thunderstorms in the same vicinity. Light to gentle breezes are noted elsewhere. Looking ahead, T.D. Nine is expected across central portions of the basin and will begin re- curving to the northeast and in the general direction of the Florida Big Bend region, reaching the Florida coast Thursday afternoon. CARIBBEAN SEA... Divergent flow aloft between an upper anticyclone over T.D. Nine in the southeast Gulf and an upper low east of the Bahamas is supporting scattered showers and thunderstorms over the north central Caribbean this morning, north of 20N to the coast of Cuba as well as the Yucatan Channel. Scattered showers and thunderstorms are training over the western portion of Cuba into T.D. Nine to the north. The normally dominant subtropical ridge north of the area is temporarily weakened due to the presence of T.D. Nine and a persistent trough north of Hispaniola, resulting in only moderate to fresh trade wind flow across the southwest Caribbean this morning. Yesterday's sounding data from Trinidad indicated a low latitude trough moved into the far southeast Caribbean early Saturday. Scttered showers and thunderstorms along with slightly stronger trade wind flow are noted across the southeast Caribbean currently. Trade winds will increase across much of the south- central Caribbean through mid week as high pressure builds north of area. ...HISPANIOLA... Scattered showers and thunderstorms will develop today over the mountainous interior portions of Hispaniola, due in part to daytime heating but also due to divergence aloft between an upper anticyclone over the southeast Gulf and an upper low to the northeast of the region. The pattern will be similar through mid week. ATLANTIC OCEAN... Aside from active tropical cyclones, scattered showers and thunderstorms are noted across the Bahamas and adjacent waters including north of the Bahamas associated with an upper low centered over the coast of Georgia. Another upper low centered near 24N68W, supporting scattered moderate convection from 23N to 26N between 65W and 70W. Elsewhere, the remainder of the central and eastern Atlc is under the influence of a surface ridge anchored by a 1022 mb high centered near 31N42W. A surface trough is evident into the ridge from 18N46W to 23N45W to 26N42W. For additional information please visit http://www.hurricanes.gov/marine $$ CHRISTENSEN