000 AXNT20 KNHC 032357 TWDAT TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 635 AM EDT SAT SEP 3 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 2230 UTC. ...SPECIAL FEATURES... Post-tropical cyclone Hermine is centered near 36.2N 73.3W at 03/2100 UTC or about 150 nm southeast of Ocean City, Maryland and about 150 nm east-southeast of Norfolk, Virginia moving ENE at 10 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Scattered moderate convection is present mainly E of the center from 34N to 37N between 65W and 69W. 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 WAVES... A tropical wave over the eastern Atlc has an axis extending from 22N30W to a 1012 mb low near 17N30W to 08N30W. The wave is moving W at 10-15 kt. Convection in this wave N of 15N is being inhibited by a dry layer of air containing African dust. Numerous moderate and scattered strong convection is present E of the wave axis from 11N to 14N between 25W and 29W. Scattered moderate convection prevails on the S side of the wave from 05N to 10N between 23W and 37W. A tropical wave is moving across the central Atlc with an axis extending from 20N54W to a 1009 mb low near 14N54W to 07N54W, moving W at 15-20 kt. This wave is embedded in a broad area of high TPW. Divergent upper-level winds are supporting numerous moderate and isolated strong convection from 13N to 17N between 51W to 58W. Satellite-derived wind data show the pres gradient on the N side of the wave is also generating a broad area of fresh to strong NE to E winds from 13N to 20N between 45W and 60W. A tropical wave extends from near Jamaica in the central Caribbean into Panama with an axis extending from 17N78W to 08N78W. This feature remains embedded in an area of deep-layer moisture, as noted in TPW imagery. Isolated moderate convection is observed within 120 nm either side of the axis of the wave. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 14N17W to the tropical wave near 12N30W to 10N40W to the tropical wave near 12N54W to end just E of Trinidad and Tobago near 11N59W. Aside from the convection associated with the tropical waves, little convection is observed in the vicinity of the monsoon trough. ...DISCUSSION... GULF OF MEXICO... A surface trough extends across the western Gulf of Mexico from 19N92W to 23N95W to 27N93W. Scattered moderate convection exists near the trough from 21N to 26N between 92W and 99W. A small thermal surface trough over the western portion of the Yucatan Peninsula is enhancing convection over the SW portion of the peninsula. To the E, a surface trough extends from 27N88W to the Florida Big Bend at 30N84W to 30N82W. Scattered moderate convection prevails near this trough from 24N to 31N between 84W and 91W. Scatterometer data generally depicts light to moderate E to SE winds over the basin. An upper-level trough will continue to provide a favorable environment for deep convection over the western Gulf during the next 24 hours. CARIBBEAN SEA... A tropical wave is moving across the central Caribbean. Please refer to the tropical waves section for details. An upper-level low is over the Caribbean S of the Dominican Republic near 17N67W. This feature is generally associated with convergent upper-level winds. An upper-level trough over the far SW Caribbean is sparking isolated convection over central America. Scatterometer data depicts moderate to locally fresh trade winds across the basin, except in the vicinity of the monsoon trough S of 12N over the SW Caribbean. The tropical wave over the central/west Caribbean will continue moving W and usher in an increase in the trades over the S central Caribbean. The next tropical wave is already beginning to affect the eastern Caribbean with showers and thunderstorms. Fresh to strong easterly winds will accompany the northern portion of this wave. ...HISPANIOLA... Fair weather prevails across the island at this time beneath a region of convergent upper-level winds. A tropical wave will bring increasing easterly winds across the island as well as increased shower and thunderstorm coverage by Sunday. ATLANTIC OCEAN... Post-tropical cyclone Hermine is located of the E coast of the United States near 36N73W. Please refer to the special features section for details. Two tropical waves are moving across the basin. Please refer to the tropical waves section for details. Satellite-derived winds indicated strong to near gale-force SW winds extended S from Hermine as far as 31N. To the W, a surface trough extends from eastern Cuba at 20N76W to the central Bahamas at 26N75W. There was little convection associated with this feature. A surface ridge dominates the remainder of the basin. The ridge stretches between 1022 mb highs centered near 32N25W and 29N65W. Post-tropical cyclone Hermine will remain N of the discussion area during the next 24 hours. However, fresh to strong winds and large swell will continue to affect the NW portion of the discussion area through the weekend. The tropical waves will continue to produce showers and thunderstorms as they move W across the central tropical Atlc through late Sunday. For additional information please visit http://www.hurricanes.gov/marine $$ CAM