000 AXNT20 KNHC 270548 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 147 AM EDT Wed Sep 27 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURES... Tropical Storm Maria is centered near 34.8N 73.0W at 27/0600 UTC or about 126 nm east of Cape Hatteras North Carolina, moving north at 4 kt. Minimum central pressure is 976 mb. Maximum sustained winds are 60 kt with gusts to 75 kt. Maria is a very large cyclone with tropical storm-force winds extending outward up to 200 nm from the center. Scattered moderate convection is within 330 nm of the storm in the eastern semicircle. Stable air on the western semicircle is resulting in mainly showers within 300 nm west of the center. Buoy data indicates seas of 15 ft extending nearly 300 nm southeast of the center, with 8 ft seas about 420 nm south and southeast of the center. See the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC for more details. Hurricane Lee is centered near 30.0N 55.5W at 27/0300 UTC or about 495 nm ESE of Bermuda. Lee is moving to the west at 8 kt. Estimated minimum central pressure is 971 mb. Maximum sustained winds are 95 kt with gusts to 115 kt. Lee is a small cyclone with numerous moderate and isolated strong convection confined to within 90 nm of the center. Lee is forecast to remain a hurricane the next couple of days as it turns toward the west-northwest by Wednesday, then turns northeast on Thursday. See the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC for more details. ...TROPICAL WAVES... A tropical wave is off the coast of Africa with axis extending along 18W/19W from 04N-13N, moving west at 15 kt. SSMI TPW imagery shows a very moist area. Surface and 700 mb trough are also present. Scattered moderate isolated strong convection is E of the wave axis from 07N-13N between 12W-17W. A tropical wave extends along 44W/46W from 06N-18N, moving west at 15 kt. This wave is well defined in 700 mb wind fields. A fairly dry and stable environment covers the northern portion of the wave. Scattered showers are south of 13N between 41W-49W. A tropical wave is in the central Caribbean along 73W, from 10N- 19N, moving west at 10 to 15 kt. The wave is embedded within a moist area ,and weak 700 mb trough. Isolated moderate convection is within 90 nm of the wave axis. This convection is also partially due to upper level diffluence over the region. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the coast of Africa near 13N16W to 10N22W to 09N42W. The Intertropical Convergence Zone extends from 09N48W to 09N61W. Aside from convection associated with the tropical waves, isolated moderate convection is from 09N-13N between 50W-60W. ...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. In the upper levels, a large upper level trough is over the western half of the U.S. with axis along 113W. 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 28N83W 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 Yucatan Channel, Yucatan Peninsula, and the Bay of Campeche. CARIBBEAN SEA... A surface trough is over the W Caribbean from 22N87W to 16N88W. Scattered moderate convection is over the NW Caribbean, Cayman Islands, and Jamaica, from 17N-22N between 76W-85W. Much of this convection is also enhanced by upper level diffluence. A tropical wave is over the central Caribbean. Elsewhere, scattered showers are over the Leeward and Windward Islands, while Puerto Rico has fair weather. Lastly, the eastern extent of the E Pacific monsoon trough is well into the SW Caribbean extending from NE Nicaragua to N Colombia. Isolated moderate convection is from 11N-16N between 75W-87W. Expect over the next 24 hours for continued showers and convection over the W Caribbean and Central America W of 75W. ...HISPANIOLA... A tropical wave is presently over Haiti supporting isolated showers and thunderstorms. The wave will move west of the island on Wednesday. However, upper level conditions will support additional mainly afternoon and evening showers and thunderstorms on Wednesday. ATLANTIC OCEAN... Two tropical waves are moving across the basin. Please refer to the tropical waves section above for details. Tropical Storm 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 eastern 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 from 22N-28N, west of 71W. Elsewhere, surface ridging prevails across much of the remainder of the central and the eastern Atlantic, anchored by a 1021 mb high centered near 34N42W. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa