000 AXNT20 KNHC 211725 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1225 PM EST Sun Jan 21 2018 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 1745 UTC. ...MONSOON TROUGH/ITCZ... The African monsoon trough enters the Atlantic Ocean near 04N08W and continues to 01N22W. The ITCZ begins near 01N22W and extends to 01N37W to 02N50W. Scattered moderate convection is within 175 nm N of the ITCZ. Isolated showers are within 210 nm S of the ITCZ. ...DISCUSSION... ...GULF OF MEXICO... Ridging extends across the SW N Atlantic waters, across the Florida Peninsula and into the Gulf. Moderate to fresh southeast return flow is observed over the northwest Gulf between the ridge and lower pressure over the central Plains. Fresh easterlies are also noted over portions of the Straits of Florida. Moderate east to southeast winds persist elsewhere. A mid to upper level short- wave trough over the SE CONUS extending across the E Gulf along with the western periphery of a ridge over the Caribbean continue to support diffluent flow over the NW Caribbean and into portions of the SE Gulf. This environment aloft along with shallow moisture is supporting isolated showers in the Florida Straits. Dense fog continue to be reported in the NW basin N of 25N W of 91W. Caution must be exercised transiting in this area. Moderate to fresh SE winds will continue across the western Gulf through tonight ahead of the next cold front to move southeast off the Texas coast before sunrise on Mon. The cold front will extend from Dixie, Florida SW to the eastern Bay of Campeche Tue morning, and from the Straits of Florida to the Yucatan Peninsula Wednesday morning. Fresh to strong northerly winds will accompany the passage of the front. ...CARIBBEAN SEA... Clusters of showers and thunderstorms are ongoing across the northwest Caribbean, related to diffluence aloft at the base a sharp mid to upper trough extending from the SE CONUS into the E Gulf. Fresh to near gale-force trade winds are noted in latest scatterometer data over much of the central Caribbean with the strongest winds being along the coast of Colombia. Seas are 10 to 14 ft over the south central Caribbean with highest seas off Colombia. Moderate to fresh trades are noted in the eastern Caribbean and east of the Windward and Leeward Islands. Persistent ridging north of the area will allow strong to near gale force trades to pulse along the northwest coast of Colombia through Friday. The tail of a cold front is forecast to reach the NW Caribbean waters by late Wednesday night. Fresh to strong northeasterly winds will populate the NW Caribbean waters through Friday as the front continues to move SE across the SW N Atlc waters. Moderate to fresh trades will continue across the tropical Atlc waters E of the Windwards through Friday. ...ATLANTIC OCEAN... Ridging covers the SW N Atlc waters being anchored by a 1026 mb high pressure area centered near 29N62W. Diffluence aloft on the east side of a mid to upper trough over the E Gulf of Mexico is supporting isolated showers off the Florida coast and across the Bahamas to 70W. Former cold front over the central Atlc waters has stalled along 30N40W to 23N51W to 21N58W where it starts to dissipate. Latest scatterometer data show fresh trade winds across the Turks/Caicos and southern Bahamas, along the dissipating stationary front. Scattered showers are noted N of 23N between 30W and 46W. A 1036 mb high pressure centered over SW Portugal adjacent waters extends a ridge over the eastern Atlc region north of 20N. Farther south, moderate to fresh trade persist across the deep tropics. The High pressure will shift east to just southwest of Bermuda through Mon, then shift north of Bermuda Mon night allowing a cold front to move off the northeast Florida coast Tue afternoon. The cold front will reach from near Bermuda to Straits of Florida Wed night and from 27N65W to Central Cuba on Thu night. Strengthening high pres in the wake of the front will support strong NE wind W of 73W. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos