000 AXNT20 KNHC 240006 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT TUE AUG 23 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... Tropical Storm Gaston is centered near 14.2N 35.8W at 23/2100 UTC or about 665 nm west of the southernmost Cabo Verde Islands, moving west-northwest at 16 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Scattered moderate to isolated strong convection is from 12N-16N between 33W-38W. Please see the latest NHC Forecast/ Advisory under the AWIPS/WMO headers MIATCMAT2/WTNT22 KNHC for more details. A tropical wave is located at about 160 nm east of the Leeward Islands with axis from 22N60W to a 1009 mb low near 17N58W to 11N56W, moving west-northwest at 15-20 kt. Moisture continues to increase in the wave's environment. Scattered moderate to isolated strong convection is from 12N-23N between 54W-62W. Large-scale conditions could become more conducive for tropical development later this week while the system moves near Hispaniola and then the southeastern and central Bahamas. Interests from the islands of the northeastern Caribbean Sea to the Bahamas should monitor the progress of this system. Despite of the tropical development, gusty winds, heavy rains, and possible flash floods and mud slides could occur over these areas. This system has a medium chance for tropical formation within the next 48 hours. ...TROPICAL WAVES... The northern portion of a tropical wave extends across the Bay of Campeche and southern Mexico with axis from 21N95W to 10N96W, moving west at 15-20 kt. This wave is embedded in subtle 700 mb troughing. Scattered moderate convection is from 15N-24N between 95W-99W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 13N17W to 12N28W. The ITCZ begins near 07N43W and continues to 06N58W. Other than convection associated with T.S. Gaston and the tropical wave, scattered moderate convection is from 07N-12N between 22W-25W. ...DISCUSSION... GULF OF MEXICO... Surface ridging extends over the northern Gulf of Mexico anchored by a 1021 mb high over N Mississippi near 34N90W. This ridge supports gentle winds over the northern Gulf, and mainly moderate east to southeasterly winds over the remainder of the Gulf. Scattered moderate to isolated strong convection is over the NE Gulf and Florida. Isolated moderate convection is over the SE Gulf and the Straits of Florida. A tropical wave extends across the Bay of Campeche and southern Mexico S of 21N95W, with scattered moderate convection from 15N-24N between 95W-99W. Expect over the next 24 hours for the tropical wave to move west with convection. Also expect continued convection over the E Gulf and Florida. CARIBBEAN SEA... The pressure gradient between high pressure over the western Atlantic and lower pressures over Colombia supports fresh breeze winds from 11N-16N between 69W-82W. Moderate trade winds prevail elsewhere over the Caribbean basin. Scattered moderate convection is over the N Colombia, the SW Caribbean, Panama, and Costa Rica due to the monsoon trough. Isolated moderate convection is over Hispaniola, Jamaica, and Cuba. A tropical wave and associated low just east of the Leeward Islands will produce abundant convection. Environmental conditions could become conducive for tropical development of this system later this week. Please see the Special Features section above for further details. ...HISPANIOLA... Isolated moderate convection is inland over Hispaniola due to maximum heating. More tropical moisture is forecast to advect over the island Wednesday. ATLANTIC OCEAN... The main features of interest in the basin continue to be Tropical Storm Gaston, and the tropical wave just east of the Leeward islands. Islated moderate convection is over the W Atlantic and the N Bahamas, W of 70W. The remnant 1014 mb low of Fiona is centered near 27N65W. Scattered moderate convection is from 25N-31N between 58W-68W. The remainder of the area is dominated by a surface ridge anchored by two high pressure centers located just N of our area of discussion. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa