000 AXNT20 KNHC 291745 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 145 PM EDT THU SEP 29 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 1730 UTC. ...SPECIAL FEATURES... Tropical Storm Matthew at 29/1500 UTC is centered near 14.2N 66.3W or about 252 NM south of San Juan Puerto Rico, moving west at 13 KT. Maximum sustained winds are 60 KT with gusts to 75 KT. Estimated minimum central pressure is 996 mb. Scattered to numerous showers and thunderstorms are observed from 10N-19N between 59W-68W and another area of scattered moderate convection is south of 14N between 68W-73W. Matthew is forecast to become a hurricane within the next 24 hours. Please refer to the NHC forecast/advisory under AWIPS/WMO headers WTNT24 KNHC/TCMAT4, or visit the NHC website at http://hurricanes.gov for additional details. ...TROPICAL WAVES... A tropical wave is in the E Atlantic extending its axis from 18N25W to 08N26W, moving west at 15 kt over the past 24 hours according to satellite and global model guidance. Abundant moisture and a diffluent wind environment at the middle and upper levels support scattered moderate convection from 12N-19N between 20W-30W. A tropical wave is in the Central Atlantic with axis from 14N35W to 10N35W, moving west at 15 kt over the past 24 hours. Latest TPW imagery show dry air in the northern portion of the wave that along dust explains the lack of convection at the time. Isolated showers are observed ahead of the wave's axis and along and south of 14N between 34W-42W. A tropical wave is in the Central Atlantic with axis from 14N36W to a 1011 mb low near 10N47W to 05N47W, moving west at 15 kt over the next 24 hours. The convection observed around these features is mostly related to the proximity of the ITCZ which has scattered moderate showers and thunderstorms south of 12N between 41W-50W. A weak tropical wave is in the west Caribbean extending its axis from 19N87W to EPAC near 10N89W, moving west at 15 KT over the past 24 hours. TPW imagery depicts moderate moisture prevailing across the northern portion of the wave but despite this, no significant convection is observed with this wave at this time. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends over Africa reaching the east Atlantic near 14N17W through 08N33W. The ITCZ begins near 08N33W to 07N59W. Aside from the convection associated with the tropical waves, scattered moderate convection is south of 12N between 41W-50W. ...DISCUSSION... GULF OF MEXICO... A cold front extends across the northern portion of the basin from 27N97W to 30N85W. Isolated showers are observed along this boundary. To the south; a diffluent flow aloft supports scattered moderate convection with a surface trough extending over the Bay of Campeche from 26N96W to 20N95W. The convection is from 21N-26N and west of 93W. Isolated showers prevail across the remainder of the basin east of 89W. Scatterometer data depicts light to gentle northwesterly winds across the basin. Expect for the cold front to continue moving south across the basin during the next 24 hours. Convection will prevail ahead of this boundary affecting the southern Gulf waters. CARIBBEAN SEA... The main feature of concern in the Caribbean is T.S. Matthew located south of Puerto Rico. Please refer to the section above for details. An upper-level trough extends across the Florida Peninsula reaching the west Caribbean waters west of 80W. Scattered showers are observed south of 16N between 80W-84W affecting portions of Nicaragua and Honduras as well as their adjacent waters. Isolated showers are observed south of 10N between 78W-82W due to the proximity of the EPAC Monsoon Trough. Scatterometer data depicts moderate to fresh northeasterly winds across the basin west of 70W. Expect for Matthew to become a hurricane within the next 24 hours. This system will continue moving west through Friday. ...HISPANIOLA... Fair weather prevails across the island. T.S. Matthew is forecast to move south of Hispaniola as a hurricane by Friday through Sunday. Cloudiness associated with this system is expected to spread over the island today with an increase in showers and thunderstorms late tonight into Friday. The heaviest rain is expected Sunday, especially over the western portion of the island. For additional information on Matthew, please refer to the special features section above. ATLANTIC OCEAN... Three tropical waves are moving across the basin. Please refer to the section above for details. A broad mid-level trough extends across the southeast CONUS and covers the west Atlantic waters W of 76W, supporting scattered showers and thunderstorms between 70W-80W. The remainder basin is dominated by a surface ridge anchored by a 1036 mb high in the north central Atlantic near 41N39W. For additional information please visit http://www.hurricanes.gov/marine $$ ERA