000 AXNT20 KNHC 210002 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 802 PM EDT Tue Mar 20 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...SPECIAL FEATURES... ...ATLANTIC OCEAN GALE WARNING... A cold front is exiting the Georgia and Florida coastlines entering the west Atlantic this evening. Gale force southwest winds are noted ahead of the front north of 29N and west of 78W, with seas building to 9 ft. The Gale Warning will continue through the next 24-36 hours as the front continues moving east across the west Atlantic. Please refer to the High Seas Forecast product under WMO/AWIPS headers FZNT02 KNHC/HSTAT2 for more details. ...GULF OF MEXICO GALE WARNING... The same cold front described above extends across the east Gulf of Mexico from 30N84W to 24N90W then tot he Bay of Campeche. Near- gale force northwesterly winds with frequent gusts up to gale force are noted behind the front north of 26N west of the front to 92W. tHese conditions will continue through the next 18 hours. Please refer to the High Seas Forecast product under WMO/AWIPS headers FZNT02 KNHC/HSTAT2 for more details. ...GALE WARNING for the METEO-FRANCE areas... Please refer to the METEO-FRANCE High Seas Forecast, that is listed on the website: WWW.METEOFRANCE.COM/PREVISIONS-METEO- MARINE/BULLETIN/ GRANDLARGE/METAREA2. Gale-force winds are forecast for the area that is called: AGADIR, TARFAYA, and CANARIAS. The OUTLOOK, for the 24 hours that follow the forecast that is valid until 21/1200 UTC, consists of: the persistence of a N or NE near gale or gale in: AGADIR, TARFAYA, CANARIAS, and CAP BLANC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 08N13W, to 04N20W. The ITCZ continues from 04N20W to 01N30W, to Brazil near 03N51W. Scattered moderate convection is within 120 nm either side of the boundaries between 16W and 30W. ...DISCUSSION... GULF OF MEXICO... Please read the Special Features section for information about the Gale Warning in the Gulf of Mexico. Upper level westerly wind flow is moving across the open waters of the Gulf of Mexico. A cold front passes from the Florida Panhandle near 31N85W to 25N90W to N of Tampico Mexico near 23N98W. A surface trough is over the SW Gulf from 24N90W to 18N93W. Scattered to numerous showers and thunderstorms have developed along the front mainly across the far east Gulf waters east of 84W affecting the Florida Peninsula. The current cold front will shift SE across the forecast waters, moving SE of the area by early Wednesday. High pressure will build in the wake of the front. CARIBBEAN SEA... Undersea volcano Kick'em Jenny, north of Grenada near 12.18N 61.38W, is in a state of unrest. The government of Grenada advises mariners to observe a 5 km or 3.1 nm exclusion zone around Kick'em Jenny. Please refer to the webpage, www.nadma.gd, for additional information. Broad upper level anticyclonic wind flow spans the area. A surface ridge passes from the Atlantic Ocean at 23N70W to W Cuba near 23N84W. A 1008 mb low is centered over N Colombia. The resultant surface pressure gradient will support fresh to locally strong trade winds across the south central Caribbean Sea during the next several days. Winds will reach near gale force along the NW coast of Colombia during the overnight hours. ATLANTIC OCEAN... Please read the Special Features section for information about the Gale Warning in the Atlantic Ocean. An upper level trough is in the central Atlantic Ocean supporting a surface trough that extends from 32N53W to 28N60W. Scattered showers are N of 27N between 46W and 50W. A surface ridge extends from a 1031 mb high pressure centered near 35N26W to 25N50W. The surface trough will move eastward today. A strong cold front has entered the region off the Florida/Georgia coasts. Numerous showers and thunderstorms are noted with the front affecting the waters west of 74W. Gale-force winds will continue north of 29N through Wednesday night as the front moves eastward. The wind speeds and sea heights will diminish on Thursday, as the front reaches from Bermuda to the Windward Passage, then continues E and weakens slowly. For additional information please visit http://www.hurricanes.gov/marine $$ ERA/MT