000 AXNT20 KNHC 041151 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...SPECIAL FEATURES... Hurricane Matthew is centered near 17.8N 74.4W at 04/0900 UTC or about 30 nm south of Tiburon, Haiti and about 145 nm south of the eastern tip of Cuba moving north at 8 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 within 90 nm of the center over the south semicircle. Scattered moderate to isolated strong convection is within 150 nm of the center over the north semicircle and within 210 nm of the center over the remainder of the south semicircle, and from 14N-21N between 67W-71W, including Hispaniola, western Jamaica, and eastern Cuba. 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. Although this system remains fairly organized, the satellite images indicate that the low level circulation is elongated and the low does not have a well-defined center. However, only a slight increase in organization of this system would result in the formation of a tropical depression during the next day or two. There is a high chance of tropical development during the next 48 hours as it moves northwestward 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 15N46W to 8N52W moving west-northwest at near 15 kt over the past 24 hours. Wave is moving through an area between two upper ridges enhancing scattered moderate to strong convection within 180 nm southeast of the wave axis, within 270 nm northwest of the wave axis south of 15N, and within 60/75 nm of a line from 16N38W to 2N45W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from a 1009 mb low inland over west Africa into the east Tropical Atlantic near 12N16W to 9N19W where the ITCZ begins and continues along 4N32W to 7N43W. Clusters of scattered moderate convection are within 150 nm either side of the ITCZ between 25W-36W and within 250 nm either side of the ITCZ between 36W-43W. ...DISCUSSION... ...GULF OF MEXICO... An upper trough extends over the southeast CONUS into the central Gulf from west Georgia 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 southeast Gulf generating isolated showers and thunderstorms north of 27N east of 85W to over the north portion of the Florida peninsula. A weak surface trough is along the west side of the upper trough extending from 27N94W to 23N94W. Isolated showers and possible isolated thunderstorms are from 22N-29N between 89W-95W. The surface trough will gradually dissipate through today. A surface ridge will build across the eastern CONUS into the northwest Gulf tonight through early Wednesday. Winds and seas will increase over the east Gulf Wednesday through the end of the week as Hurricane Matthew moves northward across the Bahamas and off or near the east coast of Florida. ...CARIBBEAN SEA... The primary concern this morning is Hurricane Matthew moving north across Hispaniola and toward eastern Cuba. See Special Features above. An upper ridge dominates most of the Caribbean this morning with the upper trough over the Gulf of Mexico extends south to over the Yucatan peninsula covering the far west Caribbean. Diffluence associated with the upper ridge is generating scattered showers and possible isolated thunderstorms east of Hurricane Matthew north of 16N between 62W-67W including the Virgin Islands and Puerto Rico. Hurricane Matthew is expected to track north through late tonight before turning to the north-northwest Wednesday. This will take Matthew toward eastern Cuba later today, then will continue away from the Caribbean Wednesday. ...HISPANIOLA... The eye of Hurricane Matthew is approaching the southwest peninsula of Haiti this morning. The outer rainbands of Hurricane Matthew are continue to move across the island bringing numerous showers and isolated thunderstorms. Hurricane conditions are expected to be across portions of Haiti this morning with tropical storm conditions across the remainder of Haiti and over portions of the Dominican Republic. 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 this morning is Hurricane Matthew moving north across the north/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 31N76W where a surface trough continues along 29N79W to over the Florida peninsula near Melbourne. Scattered showers and isolated thunderstorms are east of the surface trough from 25N-32N between 69W-78W. An upper ridge dominates the west Atlantic east of 60W and is associated with Hurricane Matthew. Scattered showers and isolated thunderstorms are south of a line from 25N78W to 22N68W. An upper trough over the far east Atlantic is supporting a dissipating front to 31N29W with a surface trough continuing to 30N35W. This frontal boundary is splitting a surface ridge that dominates the remainder of the central and east Atlantic, anchored by a 1026 mb high northeast of the Azores and and 1021 mb high near 28N48W. Hurricane Matthew is expected to move out of the Caribbean early Wednesday with conditions over the Turks and Caicos to begin to deteriorate later today. Matthew is expected to track north- northwest Wednesday with a gradually turn to the northwest Wednesday night. This will take Matthew near or over the southeastern and central Bahamas tonight and Wednesday and approach the northwestern Bahamas Wednesday night. Matthew will move north of the discussion area late Friday. For additional information please visit http://www.hurricanes.gov/marine $$ PAW