000 AXNT20 KNHC 300604 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 204 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...SPECIAL FEATURES... Hurricane Gaston is centered near 31.6N 54.6W at 30/0300 UTC or about 520 nm east of Bermuda and about 1400 nm west of the Azores moving northeast at 5 kt. Estimated minimum central pressure is 968 mb. Maximum sustained wind speed is 90 kt with gusts to 110 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 33.8N 74.1W at 30/0300 UTC or about 110 nm southeast of Cape Hatteras North Carolina moving northwest at 4 kt. Estimated minimum central pressure is 1011 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is observed within 120 nm in the northeast semicircle of the center. 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 23.9N 85.5W at 30/0300 UTC or about 210 nm west of Key West Florida and about 175 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. Scattered moderate convection is observed within 90 nm in the southwest semicircle of the center. See latest NHC Forecast/Advisory under the AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...TROPICAL WAVES... A tropical wave is analyzed from 09N34W to 18N34W moving west at 10 to 15 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. There is , and there is little evidence of this feature at the surface at this time, although that cannot be ruled out. 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 08N15W to 1008 mb low pressure near 15.5N16.5W to 20N16W. 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 Gambia and Senegal. The tropical wave is expected to stay intact as it tracks westward across the Atlantic over the next several days, accompanied by areas of strong winds, seas to 8 ft and scattered showers and thunderstorms. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from 10N20W to 08N27W to 10N40W to 08N45W. The Intertropical Convergence Zone axis extends from 08N45W to 07N55W. Scattered moderate convection is evident within 120 nm south of the monsoon trough and ITCZ axes. ...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. Buoy observations and an earlier scatterometer pass indicated easterly winds of 20 to 30 kt across much of the eastern Gulf north T.D. Nine and east of 85W. A weak trough remains in place over the northwest Gulf reaching from a 1009 mb low pressure system centered near 27N97W to 25N94W. 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. Earlier shower and thunderstorm activity over the northeast Gulf has diminished. 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 15N between 75W and 85W. 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. Clusters of thunderstorms over Central America earlier in the evening have weakened and shifted to the Pacific coast. Recent sounding data from Trinidad indicated a low latitude trough moved into the far southeast Caribbean early Saturday. Slightly stronger trade wind flow is noted across the southeast Caribbean currently, reaching as far west as Curacao where winds to 25 kt are noted. Trade winds will increase across much of the south- central Caribbean through mid week as high pressure builds north of area. ...HISPANIOLA... The scattered showers and thunderstorms from earlier this afternoon have dissipated as daytime heating as decreased. The showers and thunderstorms were enhanced in part by divergence aloft related to an upper low centered north of the area. 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 20N43W to 27N41W. For additional information please visit http://www.hurricanes.gov/marine $$ CHRISTENSEN