000 AXNT20 KNHC 011204 TWDAT TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 AM EDT SAT OCT 1 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 1000 UTC. ...SPECIAL FEATURES... Hurricane Matthew is centered near 13.4N 73.1W at 01/1200 UTC or about 317 nm S of Port Au Prince Haiti and about 348 nm SE of Kingston Jamaica moving W at 6 kt. Estimated minimum central pressure is 947 mb. Maximum sustained wind speed is 135 kt with gusts to 165 kt. Numerous strong convection is from 11N-15N between 68W-75W. Scattered moderate convection is elsewhere from 09N-17N between 67W-76W. 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. ...TROPICAL WAVES... A tropical wave is in the central Atlantic extending from a 1010 mb low near 13N34W to 20N33W, moving W at 15-20 kt over the past 24 hours. The wave is in a region of favorable deep layer wind shear and in a region of middle level diffluence. However, the TPW and CIRA LPW imagery show dry air intrusion W of the wave axis. Meteosat enhanced imagery confirm the presence of Saharan dry air and dust in the wave environment, which is inhibiting convection at the time. A tropical wave is in the central Atlantic extending from a 1008 mb low near 14N51W to 23N52W, moving WNW at 10-15 kt over the past 24 hours. The wave is in a region of unfavorable deep layer wind shear and Saharan dry air and dust is observed mainly W of its axis. Low level moisture and middle level diffluence support scattered showers and isolated tstms from 11N to 23N between 43W and 55W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from 11N15W to 09N24W to 09N36W. The ITCZ begins near 09N36W and continues to 09N45W. For information about convection see the tropical waves section above. ...DISCUSSION... GULF OF MEXICO... A broad deep layered low is centered over Indiana with troughing dipping southward over the eastern Gulf and a portion of the NW basin. The upper trough supports a stationary front extending across the northern Florida peninsula to 27N83W to 25N90W to 21N97W. The base of the upper trough extends S to Honduras and generates a diffluent environment over the far SE basin to support scattered to isolated showers across the Florida Straits and the Yucatan Channel. Scattered showers are occurring across the SW Gulf generally S of the front W of 93W due in part to a diffluent environment aloft between the troughing and a broad upper level anticyclone centered S of the Baja California Peninsula. Clear skies prevail N of the frontal boundary as a surface ridge remains anchored across the central plains. The front is expected to gradually become diffuse through Sunday with light to gentle E-NE winds expected as ridging slides eastward to the N across the SE CONUS. CARIBBEAN SEA... The main concern in the basin is Hurricane Matthew located in the south-central Caribbean. See the special features section for details. An upper level ridge covers much of the Caribbean E of 80W while the base of an upper level trough extends from the Florida Straits to over Honduras. The upper level trough supports isolated showers across the NW Caribbean S of 20N W of 83W. Across the SW Caribbean...the Monsoon Trough axis extends along Costa Rica to northern Colombia and provides focus for scattered showers and tstms S of 14N. Otherwise, as Matthew tracks N-NW across the central Caribbean through Monday, the trades will continue to be disrupted. Trades will begin to re-establish from east to west Wednesday through early next weekend. The next tropical wave will move across the Lesser Antilles Sunday night. ...HISPANIOLA... High level cloudiness associated with Hurricane Matthew in the south-central Caribbean continue to cover the Island. Isolated showers are likely occurring over the southern Dominican Republic and Haiti as well as the Windward Passage. Matthew is expected to track W through tonight before making a turn toward the NW then north late in the weekend. Heavy showers are expected across the Island from Sunday night through Wednesday when the cyclone will be moving across the northern Bahamas. ATLANTIC OCEAN... The deep layered trough over the eastern Gulf of Mexico extends over the far western portions of the SW North Atlc west of 76W supporting a stationary front extending from 31N79W to 27N82W then across the Gulf of Mexico waters to 21N97W. Scattered showers and isolated tstms prevails N of 23N W of 73W being supported by the trough aloft. The remainder of the Atlc is under the influence of a surface ridge anchored by a 1022 mb high near the Azores. The surface ridge is expected to persist through the weekend as Matthew moves through the Caribbean Sea. The ridge will shift east as Matthew moves into the SW North Atlc by early Tuesday. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS