000 AXNT20 KNHC 281033 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 633 AM EDT Thu Sep 28 2017 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 1015 UTC. ...SPECIAL FEATURES... Tropical Storm Maria is centered near 36.8N 71.0W at 28/0900 UTC or about 238 nm east-northeast of Cape Hatteras North Carolina, moving ENE at 7 kt. Minimum central pressure is 982 mb. Maximum sustained winds are 60 kt with gusts to 75 kt. Maria is a large tropical cyclone with tropical storm force winds extending up to 200 nm from the center. Scattered moderate convection is within 270 nm of the storm in the northeastern semicircle. Stable air on the southwestern semicircle is resulting in mainly showers within 300 nm southwest of the center. See the latest NHC Forecast/ Advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC for more details. Hurricane Lee is centered near 32.5N 57.2W at 28/0900 UTC or about 386 nm E of Bermuda. Lee is moving N at 8 kt. Estimated minimum central pressure is 966 mb. Maximum sustained winds are 95 kt with gusts to 115 kt. Lee is a small tropical cyclone with numerous moderate convection within 120 nm of the center. Lee is forecast to remain a hurricane through Friday evening as it accelerates over open ocean. See the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...TROPICAL WAVES... A tropical wave off the coast of Africa is along 25W from 16N to 05N, moving west at 15 kt. This wave is embedded in a very moist environment, and a sharp 700 mb trough. Widely scattered moderate convection is within 180 nm of either side of the wave axis. A tropical wave is in the central Atlantic along 51W/53W from 16N to 06N, moving west at 10 to 15 kt. This wave is evident in 700 mb wind fields and is generating isolated moderate convection within 180 nm of either side of the wave axis. A tropical wave in the western Caribbean along 87W from 20N to 09N, moving west at 10 kt. The wave is embedded within a moist environment, and a 700 mb trough. Isolated moderate convection is within 180 nm of either side of the wave axis. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the coast of Africa near 11N16W to 06N25W to 07N36W. The Intertropical Convergence Zone extends from 07N36W to 10N51W, then resumes west of a tropical wave near 10N54W to 10N61W. Aside from convection associated with the tropical waves, widely scattered moderate convection is from 10N- 16N between 56W-62W. ...DISCUSSION... GULF OF MEXICO... Slight surface ridging is over the N Gulf of Mexico, with mostly 5-15 kt E flow over the Gulf. Strongest winds are over the W Gulf W of 90W. A surface trough is over the Bay of Campeche from 22N92W to 16N93W. Scattered moderate to isolated strong convection is within 120 nm of the trough. In the upper levels, a large upper level trough is over the western half of the U.S. with axis along 112W. Upper level diffluence E of the axis is producing convection over S Texas and Mexico between 95W-105W. An upper level low is centered over the NE Gulf of Mexico near 28N84W with strong subsidence. Again upper level diffluence SE of the center is producing showers and convection over W Cuba, the Straits of Florida, and the Bahamas. Expect over the next 24 hours for an increase of showers and convection over the SW Gulf. CARIBBEAN SEA... A tropical wave is over the western Caribbean. Elsewhere, scattered showers are over the Windward Islands advecting from the Atlantic. Lastly, the eastern extent of the E Pacific monsoon trough is well into the SW Caribbean extending from SE Nicaragua to N Colombia. Isolated moderate convection is over Panama, while N Colombia has scattered moderate to strong convection. In the upper levels, diffluence from the NE Gulf upper level low is producing scattered moderate to isolated strong convection over the central Caribbean from 15N-19N between 78W-82W. Expect over the next 24 hours for more showers and convection to advect over the E Caribbean. ...HISPANIOLA... Presently fair weather is over Hispaniola. Expect afternoon and evening showers and thunderstorms on Thursday. ATLANTIC OCEAN... Two tropical waves are moving across the basin. Please refer to the tropical waves section above for details. Hurricane Maria in the western Atlantic and Hurricane Lee in the central Atlantic are discussed in the special features section above. A plume of moisture is being pulled northeast across the Bahamas and surrounding waters by an upper low over the NE Gulf of Mexico, and by low level southerly flow well to the south of Maria. This plume combined with upper level diffluence from the upper low supports numerous showers and scattered thunderstorms W of 63W. Elsewhere, surface ridging prevails across much of the remainder of the central and the eastern Atlantic, anchored by a 1022 mb high centered near 33N40W. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa