000 AXNT20 KNHC 301748 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 PM EDT FRI SEP 30 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...SPECIAL FEATURES... Hurricane Matthew is centered near 13.6N 71.3W at 30/1800 UTC or about 75 nm north of Punta Gallinas, Colombia and about 415 nm southeast of Kingston, Jamaica moving west-southwest at 10 kt. Maximum sustained winds are 105 kt with gusts to 130 kt. Estimated minimum central pressure is 960 mb. Scattered moderate to strong convection is from 12N-15N between 66W-73W including the ABC Islands. Scattered moderate convection covers the remainder of the area from 12N-18N between 64W-74W. Matthew is expected to continue on a westerly track through late Saturday before making a turn toward the northwest then north late in the weekend. Please see the latest NHC Forecast/Advisory under AWIPS/WMO headers MIATCMAT4/WTNT24 KNHC and the Intermediate Public Advisory under AWIPS/WMO headers MIATCPAT4/WTNT34 KNHC for more details. ...TROPICAL WAVES... Tropical wave in the east Tropical Atlantic extends along 28W from 10N-20N moving west-northwest 5 to 10 kt over the past 24 hours. Wave is in the vicinity of a broad 700 mb trough and a surge of moisture. Clusters of scattered moderate to isolated strong convection are within 90 nm of line from 17N27W to 14N34W. Tropical wave in the west Tropical Atlantic extends along 49W from 9N-21N moving west-northwest at near 10 kt over the past 24 hours. Wave is embedded within a broad upper trough and within a surge of moisture. No associated deep convection is noted. Scattered showers and isolated thunderstorms are within 90/120 nm of a line from 19N49W to 25N47W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across over Africa into the east Tropical Atlantic near 13N16W then continues along 10N19W 13N27W 9N33W to 9N38W where the ITCZ begins and continues to east of a tropical wave near 12N46W then resumes west of the wave near 11N52W to South America near 8N59W. Scattered moderate to isolated strong convection is within 180 nm of a line from 12N51W to 19N41W and is due to an upper trough rather than the ITCZ or tropical wave. ...DISCUSSION... ...GULF OF MEXICO... A broad deep layered trough covers the Gulf of Mexico east of 90W with the upper low centered over southern Indiana and extends an upper trough into the west Atlantic. This is supporting a cold front that extends from the west Atlantic across Florida from Saint Augustine into the Gulf between Cedar Key and Tampa then along 26N90W to just off Mexico near 24N97W. Scattered showers and isolated thunderstorms are within 90 nm south of the front west of 88W. An upper ridge covers the west Gulf anchored over central Mexico. A weak surface trough is in the southwest Gulf extending from 24N93W along 21N93W to 19N92W. Isolated showers and possible isolated thunderstorms dot the remainder of the Gulf south of the front, leaving the skies clear north of the front. The front will stall across the Gulf later today through Saturday and dissipate Sunday as high pressure builds in across the north Gulf. ...CARIBBEAN SEA... The main concern this afternoon is Hurricane Matthew located in the central Caribbean. Please see Special Features above. An upper ridge dominates the Caribbean this afternoon with the exception of the far northwest, where the upper trough over the east Gulf of Mexico dips south to 16N west of 80W. This is generating isolated showers and thunderstorms mainly from 16N- 20N west of 86W to just inland over the Yucatan peninsula, and within 60 nm of the Isle of Youth off the south coast of Cuba. Northerly surface flow combined with southerly flow aloft is generating scattered to numerous showers and isolated thunderstorms south of 11N to inland over Panama between 76W-80W and south of 13N to the coast of Panama between 80W-83W. The remainder of the activity in the Caribbean is associated with Hurricane Matthew. Matthew is expected to continue on a westerly track through late Saturday before making a turn toward the northwest then north late in the weekend. ...HISPANIOLA... High clouds are moving across the island due to the outflow from Hurricane Matthew. Isolated showers are possible across the island through today. Matthew is expected to continue on a westerly track through late Saturday before making a turn toward the northwest then north late in the weekend. Moisture associated with Matthew is expected to move toward the island Saturday with showers and thunderstorms moving in Saturday afternoon through the Sunday as Matthew makes the turn toward a more northerly track. Please see Special Features above. ...ATLANTIC OCEAN... The deep layered trough over the east Gulf of Mexico extends over the far west Atlantic west of 74W supporting a cold front that extends through 32N80W then across the Florida peninsula near Saint Augustine continuing into the Gulf of Mexico. Skies are clear west of the front with scattered showers and isolated thunderstorms north of 24N between 73W-80W. The remainder of the Atlantic is dominated by a surface ridge west of 60W and is anchored by a 1025 mb high in the central Atlantic near 35N57W and a 1029 mb high northwest of the Azores. The west Atlantic cold front will stall and weaken through Saturday. The surface ridge will persist through the weekend as Matthew moves through the Caribbean. The ridge will shift east as Matthew moves into the west Atlantic early next week. For additional information please visit http://www.hurricanes.gov/marine $$ PAW