000 AXNT20 KNHC 171725 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Mar 17 2021 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 1700 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 12N15W to 02N25W. The ITCZ continues from 02N25W to 01N37W. Numerous moderate and scattered strong convection is observed within 360 nm of the coast of Liberia and Sierra Leone, east of 17W from 02S-07N. Isolated showers are within 210 nm N and within 180 nm S of the ITCZ and monsoon trough between 20W-36W. GULF OF MEXICO... A cold front is moving off the Texas coast and into the far western Gulf of Mexico now, as of about 17/1700 UTC, from roughly Houston TX to 27.5N96.5W to the Mouth of the Rio Grand River. Ahead of the front, fresh to strong S to SE winds prevail across the central Gulf of Mexico, per the latest ASCAT pass, where seas are likely 6 to 8 ft. A pre-frontal line of scattered showers and tstorms has formed offshore of Texas, mainly north of 27N, extending northward to the Texas/Louisiana border. This line of tstorms will move from west to east across the NW Gulf this afternoon. By midnight tonight local time, the line of tstorms will be near the coast of Mississippi and SE Louisiana. Some of the tstorms to the north of 28N are likely to be strong to severe, with frequent lightning, gusty winds, small hail and isolated waterspouts. The cold front will reach from the Florida Panhandle to the Bay of Campeche on Thu, and from southern Florida to the Yucatan peninsula on Fri. Near gale-force NW winds are expected near the Veracruz coast of Mexico Thu afternoon. The strong winds will end by Thu night. Seas will peak around 8-10 ft in the area of strongest winds Thu afternoon and Thu evening, then subside Thu night as the winds diminish. Fresh to strong winds and building seas are expected in the NE Gulf Sat night through Sun night. CARIBBEAN SEA... A recent ASCAT pass indicates the presence of a surface trough in the SW Caribbean from the SE coast of Nicaragua to the N coast of Panama near 09N80W. This surface trough and a mid-level trough over the southern portion of Central America are enhancing scattered moderate to strong convection over the SW Caribbean from 09.5N-12N between 80W-83.5W, or within 180 nm of the coasts of western Panama, Costa Rica and SE Nicaragua. Heavy rain could impact the southeast coast of Nicaragua this afternoon through tonight. A cold front extends from west of the Azores near 38N33W to Antigua near 17N62W to just south of Puerto Rico and ending inland over the Dominican Republic. Cloudiness with possible scattered showers are within 45 nm either side of the front, including near Antigua, Montserrat, Nevis and the Dominican Republic. The cold front is forecast to drift SE across the NE Caribbean through Thu. A surface trough extends from St. Lucia east-northeastward to 17N53W. Scattered showers are possible near St. Lucia and Martinique. The latest ASCAT pass shows fresh winds covering most of the Caribbean, with strong NE to E winds over the central Caribbean. Strong E to SE winds are also likely occurring in the Gulf of Honduras. Seas are likely currently 7-10 ft in the central Caribbean, 5-8 ft in the eastern Caribbean and 4-7 ft in the NW Caribbean, except 6-8 ft in the Gulf of Honduras. Strong trade winds will continue across the central Caribbean through Fri morning, with near gale-force winds expected near the coast of Colombia each night. Fresh to strong winds are expected in the Windward Passage tonight. SE winds will increase across the NW Caribbean through tonight, ahead of a cold front moving into the Gulf of Mexico. The front will stall and weaken near the Yucatan Channel Fri night and Sat. Large northerly swell will affect the Tropical N Atlantic waters and NE Caribbean Passages through Thu. ATLANTIC OCEAN... A cold front extends from 34N73W to Savannah Georgia. Ahead of the front, scattered moderate showers and tstorms are occurring from 29.5N-32N between 70W-77W. Fresh S to SW winds are located in the same area. Gentle anticyclonic winds prevail elsewhere north of 22N and west of 60W, due to surface ridging. An exception is in the Florida Straits, where fresh SE winds are seen on the latest ASCAT data pass. A cold front extends southwestward across the central Atlantic from 32N36W to 21N50W to Antigua near 17N62W, and across the NE Caribbean, ending inland over the Dominican Republic. The latest ASCAT data pass shows fresh NE winds north of the front to 22N between 52W-70W. These winds are locally strong just north of the Mona Passage. A pre-frontal surface trough is analyzed from 30N36W to 18N47W. Cloudiness and scattered light showers are along the cold front and the surface trough. Large NW to N swell of 10-20 ft covers the Atlantic behind the cold front and east of 65W, highest near 31N43W. Seas are 6 to 9 ft east of the Bahamas, in N swell. For the forecast, a cold front will move east of northern Florida Thu night, extend from near 31N71W to the Straits of Florida Fri night, then become stationary on Sat. An area of low pressure forming along the stationary front will intensify northerly winds east of northern Florida Sun and Sun night, with gale conditions possible. Farther east, the cold front from 21N50W to the NE Caribbean will drift SE today. Large northerly swell will continue to affect the waters E of 72W through Thu, then gradually diminish afterwards. Aside from some fresh to locally strong NE winds occurring Fri and Sat near 28N45W, south of a developing high pressure, the trade winds across the central Atlantic will remain moderate to fresh. $$ Hagen