000 AXNT20 KNHC 040605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT SUN SEP 4 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 0545 UTC. ...SPECIAL FEATURES... Post-tropical cyclone Hermine is centered near 36.5N 72.1W at 04/0300 UTC or about 178 nm southeast of Ocean City, Maryland moving east-northeast at 11 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Scattered moderate convection is present mainly northeast of the center from 35N to 42N between 63W and 70W. 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 extending from 07N to 22N with axis near 31W, moving west at 10 kt within the last 24 hours. A 1012 mb center of low pressure is associated with the wave and is located near 18N31W, which is expected to dissipate within the next 24 hours. The wave is mainly within a favorable deep layer wind shear from 10N to 20N, however intrusion of Saharan dry air and dust in the wave environment is hindering deep convection north of 15N. Moist air associated with the monsoon trough and a diffluent environment aloft support scattered showers from 06N to 15N between 24W and 39W. A tropical wave is over the Atlantic waters east of the Lesser Antilles extending from 08N to 19N with axis near 56W, moving west at 15-20 kt within the last 24 hours. A 1010 mb center of low pressure is associated with the wave and is located near 14N56W, which is expected to dissipate within the next 24 hours. The wave has been entering a region of unfavorable deep layer wind shear and convection around the low has diminished. Scattered moderate to isolated strong showers are from 12N to 17N between 51W and 60W. Isolated showers extend further west to the Windward Islands and Caribbean adjacent waters. A tropical wave is over the western Caribbean extending from 09N to 19N with axis near 81W, moving at 15 kt within the last 24 hours. The wave is in a favorable deep layer wind shear environment that along with diffluent flow aloft support isolated heavy showers within 60 nm either side of the wave axis south of 13N. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 14N17W to 11N31W to 11N44W to 12N53W. 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 weak surface ridge anchored by a 1018 mb high near 26N83W dominate the Gulf waters east of 90W supporting light variable wind flow. A surface trough, remnants of a former frontal boundary, extends along the Florida Panhandle coastal waters to 30N89W with scattered to isolated showers. A second surface trough is over the NW basin extending from 28N92W to 23N97W with isolated heavy showers over Mexico coastal waters between Tampico and Vera Cruz. Scattered heavy showers and tstms are in the Bay of Campeche mainly east of 95W associated with a third surface trough extending from 21N92W to 18N92W. Gentle to moderate E to SE winds are across the western basin. All the features across the basin are expected to dissipate before sunrise Monday leaving mainly moderate return flow basin-wide. CARIBBEAN SEA... A weak tropical wave is over western Caribbean waters supporting heavy showers over Nicaragua, Panama and Costa Rica adjacent waters. A second tropical wave with an associated center of low pressure is over Atlantic waters east of the Lesser Antilles. This system continues to produce a large area of cloudiness and showers, and is likely producing winds to near tropical storm force. Upper-level winds are forecast to become less conducive for any significant development of this disturbance while it moves westward through the Caribbean Sea this week. Regardless of development, this disturbance will produce locally heavy rainfall and gusty winds, possibly to tropical storm force, over portions of the Lesser Antilles Sunday afternoon through early Monday. Please refer to the tropical waves section for details. Fresh to strong winds are in the NE Caribbean as well as in the south-central basin. ...HISPANIOLA... Fair weather prevails across the island due to strong subsidence from aloft as indicated by water vapor imagery. Stable and fair weather is expected to continue through Sunday. On Monday, a moist airmass associated with a tropical wave will bring showers. ATLANTIC OCEAN... Post-tropical cyclone Hermine is N of forecast waters. 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. A surface trough, remnants of a former frontal boundary extends from 30N78W to 26N80W with isolated showers and tstms within 60 nm of its axis N of 27N. Another surface trough is moving across the central Bahamas generating similar shower activity. The remainder basin is dominated by a weak and broad surface ridge. 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. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS