000 AXNT20 KNHC 281700 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 100 PM EDT Wed Mar 28 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 1645 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, within 75 nm to 150 nm of 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 extends from Sierra Leone near 07N13W to 04N17W. The ITCZ continues from 04N17W, crossing the Equator along 34W, to 01S43W just off the coast of Brazil. Precipitation: isolated moderate to locally strong rainshowers, in a disorganized pattern, are from 07N southward from 53W eastward. ...DISCUSSION... GULF OF MEXICO... A surface ridge extends from an Atlantic Ocean 1025 mb high pressure center, that is near 29N75W, across SE Florida and NW Cuba, to the Yucatan Peninsula. A developing frontal boundary is organizing itself in Texas at the moment. The current surface ridge, from the SW N Atlantic Ocean into the eastern Gulf of Mexico, will maintain fresh-to-strong SE return flow through Thursday morning. The current Texas cold front will enter the NW Gulf of Mexico on Thursday morning. Fresh-to-strong southerly winds will develop within 60 nm to the east of the front, and in the Louisiana adjacent waters on Thursday afternoon, continuing through the evening hours. The front will reach from the Florida Big Bend to Tampico on Friday afternoon, and then the front will stall across central Florida on Saturday morning while it weakens. CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details about the gale warning for the coastal areas near Colombia. Seismic activity with undersea volcano Kick em Jenny, north of Grenada near 12.18N 61.38W has steadily declined, and the alert level for mariners has returned to normal, with an exclusion zone of 1.5 km. Please see www.nadma.gd for additional information. The SW part of a cold front, that is dissipating at the moment, passes through 20N70W, just to the north of Hispaniola, and the front reaches its endpoint across SE Cuba. Scattered to broken low level clouds and possible rainshowers cover the area that is from 16N63W 13N81W 18N87W northward between the Virgin Islands and the NW corner of the Caribbean Sea. 24-hour rainfall totals, that are listed for the period that ended at 28/1200 UTC, according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES, MIATPTPAN/SXCA01 KNHC, are: 1.51 in St. Thomas in the U.S. Virgin Islands, 0.91 in Guadeloupe, and 0.02 in San Juan in Puerto Rico. Surface high pressure, that is to the NE of Great Abaco Island in the Bahamas, will support fresh-to-strong trade winds in the south central Caribbean Sea through Saturday morning. The wind speeds will pulse to minimal gale force near the coast of Colombia each night through Friday morning. Large N to NE swell will continue to propagate into the northern Caribbean Sea through Friday morning. Fresh to strong winds will develop in the Gulf of Honduras tonight and on Thursday night. ATLANTIC OCEAN... A cold front passes through 32N54W to 27N57W, curving to 24N60W and 20N70W, and eventually to SE Cuba. A surface trough is along 26N56W, curving to 21N60W, and to 17N60W. Precipitation: widely scattered moderate to isolated strong from 18N northward between 50W and 60W. isolated moderate rainshowers from 18N southward between 50W and 60W. Surface anticyclonic wind flow covers the Atlantic Ocean from 50W eastward. A surface ridge is along 35W. An upper level cyclonic circulation center is near 27N23W in the eastern Atlantic Ocean. Precipitation: widely scattered moderate to isolated strong rainshowers are within 620 nm to the NE of the 27N23W cyclonic center. The current weakening cold front will push southeastward through this evening, and then stall before dissipating north of Puerto Rico on Thursday. Strong NE winds will affect the adjacent waters that are to the west of the central and southern Bahamas through early Friday, including the Atlantic Ocean approaches. Large north swell will impact the waters that are to the NE of the Bahamas through Friday morning. A new cold front will move off NE Florida early on Friday evening, stall N of the Bahamas on Saturday, and lift N of the area as a warm front on Saturday. For additional information please visit http://www.hurricanes.gov/marine $$ MT