000 AXNT20 KNHC 222317 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 717 PM EDT Wed Mar 22 2017 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. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 08N13W to 00N25W. The Intertropical Convergence Zone extends from 00N25W to 05S36W. Scattered moderate convection prevails within 100 nm on either side of the Monsoon Trough. ...DISCUSSION... GULF OF MEXICO... NW flow aloft prevails over the Gulf providing dry air and stable conditions. A surface high is centered near 29N92W and extends its ridge across the basin. Gentle to moderate anticyclonic winds accompany the ridge as noted on recent ASCAT data. The high is forecast to weaken slightly through the next 24 hours as a frontal boundary tries to enter the northern portion of the basin. The frontal boundary will dissipate quickly across the area. Surface ridging will prevail through the end of the week. CARIBBEAN SEA... A broad upper-level trough is noted on water vapor imagery over the northwest Caribbean while southwesterly flow aloft to the east of the trough prevails over the central and eastern Caribbean. Dry and stable air overall is providing for a lack of deep convection and mostly tranquil surface conditions at this time. A few areas of isolated showers, however, are noted on satellite imagery across the far southwestern waters south of 17N west of 80W affecting portions of Honduras, Nicaragua, and Costa Rica. Moderate to occasional fresh trades prevail across the basin and are expected to persist through Thursday night. ...HISPANIOLA... The tail end of a warm front extends north of the island across the west-central Atlantic. The proximity of this boundary is enhancing cloudiness and showers mainly over the northern half of the island. The front is expected to gradually lift northward and become absorbed by a cold front expected to impact the SW North Atlantic waters by Thursday. Any lingering remnant boundary or surface troughing will provide a slight probability of shower activity through the remainder of the week. ATLANTIC OCEAN... A cold front extends across the west Atlantic mainly north of 30N. Isolated showers and thunderstorms are developing along the front affecting the Atlantic waters between 70W-80W. To the east, a frontal system was analyzed as a stationary front from 31N47W to 25N58W, then as a warm front from that point to 21N72W. Scattered light to moderate convection is observed within 200 nm on either side of these boundaries between 55W-70W. The remainder of the basin is under the influence of a surface ridge, anchored by a 1035 mb high centered near 42N26W. Expect during the next 24 hours for the cold front to enter the west Atlantic with convection. Fresh to strong northerly winds are expected behind the front on Thursday. The front will then weaken by the end of the week as well as the winds behind it. The frontal system across the central Atlantic will dissipate within the next 24 hours. For additional information please visit http://www.hurricanes.gov/marine $$ ERA