000 AXNT20 KNHC 040602 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT TUE OCT 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 0515 UTC. ...SPECIAL FEATURES... Hurricane Matthew is centered near 17.4N 74.5W at 04/0600 UTC or about 52 nm south of Tiburon, Haiti and about 143 nm west- southwest of Port au Prince Haiti moving north at 7 kt. Estimated minimum central pressure is 934 mb. Maximum sustained wind speed is 125 kt with gusts to 150 kt. Scattered to numerous strong convection is from 15N-18N between 73W-77W. Scattered moderate to isolated strong convection is elsewhere from 13N-19N between 66W-78W, including Hispaniola and western Jamaica. See latest NHC Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC and the full Forecast/Advisory under AWIPS/ WMO headers MIATCMAT4/WTNT24 KNHC for more details. A 1012 mb surface low is centered near 23N60W that nearly coincides with a mid-level area of low pressure. This system has become better organized and has a medium chance of tropical development during the next 48 hours as it moves west-northwest to northwest at 10 to 15 kt. Scattered moderate to isolated strong convection is from 20N-25N between 55W-60W. Please see the latest Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more details. ...TROPICAL WAVES... Tropical wave extends from 13N44W to 5N50W moving west 5 to 10 kt over the past 24 hours. Wave is moving through an area between two upper ridges enhancing clusters of scattered moderate to isolated strong convection that covers the area from 7N-16N between 40W-56W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from a 1010 mb low over west Africa into the east Tropical Atlantic near 12N16W to 8N19W where the ITCZ begins and continues along 4N27W to 5N38W. Clusters of scattered maturate to isolated strong convection are from 1N-5N between 34W-42W. Clusters of scattered moderate convection are 1N-4N between 26W-34W and from 5N-8N between 31W-41W. ...DISCUSSION... ...GULF OF MEXICO... An upper trough extends over the southeast CONUS into the central Gulf from Alabama to the Yucatan peninsula. An upper ridge extends across Mexico to over the west Gulf while the upper ridge associated with Hurricane Matthew extends over the far east Gulf generating scattered showers and isolated thunderstorms north of 26N east of 85W to over the north portion of the Florida peninsula and south of 25N east of 84W through the Straits of Florida, including the Florida Keys. A weak surface trough is along the west side of the upper trough extending from 26N93W to 21N95W. Isolated showers and thunderstorms are from 22N-26N between 89W-91W. The surface trough will gradually dissipate through Tuesday. A surface ridge will build across the eastern CONUS into the northwest Gulf Tuesday night through early Wednesday. Winds and seas will increase over the east Gulf wednesday through the end of the week as Hurricane Matthew moves across the Bahamas. ...CARIBBEAN SEA... The primary concern tonight is Hurricane Matthew moving north toward the islands of Hispaniola and Cuba. See Special Features above. An upper ridge dominates most of the Caribbean tonight with the upper trough over the Gulf of Mexico extends south to over the Yucatan peninsula covering the far west Caribbean. The upper trough is generating isolated showers and thunderstorms within 60 nm along the coast of the Yucatan north of 19N. Diffluence associated with the upper ridge is generating scattered showers and isolated thunderstorms inland and within 90 nm along the south coast of Cuba east of 80W and east of Hurricane Matthew north of a line from 14N60W to 17N66W including the Lesser Antilles to Puerto Rico. Hurricane Matthew is expected to track north through late Tuesday night before turning to the north-northwest Wednesday. This will take Matthew toward southwestern Haiti tonight and Tuesday morning, then near eastern Cuba late Tuesday, and move near or over portions of the southeastern and central Bahamas Tuesday night and Wednesday. ...HISPANIOLA... The outer rainbands of Hurricane Matthew are currently moving across the island bringing numerous showers and isolated thunderstorms. Hurricane conditions are expected to reach Haiti overnight with tropical storm conditions to reach portions of the Dominican Republic before morning. Expected rainfall amounts of 15 to 25 inches across the island with isolated amounts of up to 40 inches. These rainfall amounts could produce life- threatening flash floods and mudslides. The combination of a dangerous storm surge and large and destructive waves could raise water levels by as much as 7 to 10 ft along the south coast of Haiti with amounts of 3 to 5 ft in the Gulf of Gonave, and 1 to 3 ft along the south coast of the Dominican Republic. ...ATLANTIC OCEAN... A main concern tonight is Hurricane Matthew moving north across the central Caribbean. See Special Features above. The upper trough over the eastern CONUS is supporting a cold front over the northwest Atlantic with a stationary front extending to 31N75W where a surface trough continues along 29N79W to over the Florida peninsula near Melbourne. Scattered showers and isolated thunderstorms are southeast of the surface trough from 25N-32N between 69W-80W. An upper ridge dominates the west Atlantic east of 60W and is associated with Hurricane Matthew. An upper trough over the far east Atlantic is supporting a frontal boundary to 31N29W with a surface trough continuing along 29N37W to 31N41W. This frontal boundary is splitting a surface ridge that dominates the remainder of the central and east Atlantic, anchored by a 1025 mb high north of the Azores and and 1021 mb high near 26N37W. Hurricane Matthew is expected to move out of the Caribbean early Wednesday with conditions over the Turks and Caicos to begin to deteriorate Tuesday. Matthew is expected to track north-northwest across the Bahama islands Wednesday through Thursday night. Matthew will move north of the discussion area late Friday. For additional information please visit http://www.hurricanes.gov/marine $$ PAW