000 AXNT20 KNHC 271727 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 127 PM EDT Tue Mar 27 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 1700 UTC. ...SPECIAL FEATURES... ...GALE WARNING FOR THE SOUTH-CENTRAL CARIBBEAN SEA... A surface ridge in the western Atlantic Ocean and relatively strong low pressure in northern parts of South America support winds pulsing to gale force near the coast of Colombia. The gale force winds will recur each night during the evening and overnight hours, through Friday morning, while this surface weather pattern persists. Please read the High Seas Forecast issued by the National Weather Service under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. This information also is found at the following website: www.nhc.noaa.gov/marine. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the southern coastal sections of Sierra Leone near 07N12W to 06N16W. The ITCZ continues from 06N16W, crossing the Equator along 34W, to 01S42W, off the coast of Brazil. Precipitation: widely scattered moderate to isolated strong rainshowers are from 05N southward between 23W and 51W. ...DISCUSSION... GULF OF MEXICO... A cold front passes through the Florida Keys near 23N80W to 24N83W. The cold front is dissipating from 24N83W beyond southern Mississippi. Scattered to broken low level clouds are in the waters that are between the line from Key West-to-the Florida Big Bend and 90W. Upper level anticyclonic wind flow spans the Gulf of Mexico. A strong surface ridge that extends from the western Atlantic Ocean into the western Gulf of Mexico will maintain fresh-to- strong SE return flow through Thursday morning. A cold front is forecast to enter the NW Gulf of Mexico on Thursday morning. The front will reach from the Florida Big Bend to the central Bay of Campeche on Friday morning, and then weaken from central Florida to the Yucatan Peninsula on Friday night. High pressure will build across the SE CONUS in the wake of the front, supporting NE moderate-to-fresh winds through Saturday morning. CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details about the gale warning for the coastal areas near Colombia. 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 web page, www.nadma.gd, for additional information. The southernmost point of a surface trough reaches 19N66W. Precipitation: isolated moderate rainshowers are from 16N to 20N between 62W and 69W, including around the nearby islands of the Caribbean Sea. An upper level trough passes through 20N68W to 15N71W. Upper level cyclonic wind flow is moving across the southern half of the Bahamas, SE Cuba, Hispaniola, Puerto Rico, and the Virgin Islands. High pressure in the SW N Atlantic Ocean will support fresh to strong trade winds in the south central Caribbean Sea through Saturday. The winds will pulse to near-gale force along the NW coast of Colombia each night through Friday morning, Minimal gale-force winds are expected from Wednesday night through Thursday morning. Large N to NE swells will propagate into NE Caribbean Sea passages from Tuesday night through Friday morning. ATLANTIC OCEAN... A cold front passes through 32N56W to 26N60W, 22N70W, 23N80W, and 24N83W. The cold front is dissipating from 24N83W beyond southern Mississippi. Precipitation: isolated moderate rainshowers are within 120 nm on either side of the line that passes through 32N56W 25N62W 23N70W and 23N82W. A surface trough, the remnants of a dissipating stationary front, is along 31N54W 25N58W 19N66W. Precipitation: Widely scattered moderate to isolated strong rainshowers are within 60 nm on either side of 32N53W 25N58W 19N64W. isolated moderate rainshowers are elsewhere from 16N to 20N between 62W and 69W, including around the nearby islands of the Caribbean Sea. Surface anticyclonic wind flow covers the area that is from 51W eastward. A 1033 mb high pressure center is near 37N28W. An upper level cyclonic circulation center is near 26N27W, about 700 nm to the west of the coast of the Western Sahara. Widely scattered moderate to isolated strong rainshowers are within 400 nm to 800 nm to the east of the cyclonic center, near the Canary Islands and in northern sections of the Western Sahara. The current 32N56W-to-24N83W cold front will push southward across the Bahamas today, and it will be to the E of the area late on Wednesday night. Strong NE winds will affect the Bahamas and adjacent waters through this afternoon, and then the approaches of the Windward Passage through Friday. Large NE swell will impact the waters NE of the Bahamas through Friday morning. A cold front will move off NE Florida on Friday afternoon, then stall on Saturday morning before it lifts N of the area late on Saturday. For additional information please visit http://www.hurricanes.gov/marine $$ MT