000 AXNT20 KNHC 111754 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon Mar 11 2024 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Western and Central Atlantic Significant Swell: Residual N swell will still be big enough at the central Atlantic to keep seas at 12 to 13 ft north of 28N between 38W and 46W through this afternoon. This swell is expected to subside further which will allow seas to drop below 12 ft by this early evening. A deep 977 mb frontal low pressure is moving across Nova Scotia today. Storm-force winds associated with this low has generated very large, long-period NW swell southward across the western Atlantic. Seas north of 28N between 55W and 72W will continue to build today and reach 12 to 18 ft by late this afternoon. By late Tue afternoon, these seas are anticipated to shift southeastward to near 25N between 45W and 66W, while peaking at 12 to 20 ft. On Wednesday, these seas should be near 23N between 40W and 60W and starting to decrease to between 12 and 18 ft. Afterward, a decreasing trend along with an eastward propagation will continue through Friday. Caribbean Gale Warning: A large 1027 mb high pressure over the central and southeastern US will build eastward into the western Atlantic over the next several days. Tightening pressure gradient between this high and a Colombian Low will support strong to near-gale NE winds off the northwestern Colombia coast most of this week. These winds will pulse to gale-force during the nighttime and early morning hours tonight through Wednesday morning. Seas under the gale-force winds will peak between 10 and 12 ft. Mariners need to monitor these hazardous marine conditions and plan their route accordingly. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at websites: https//www.nhc.noaa.gov/text/MIAHSFAT2.shtml and https//www.nhc.noaa.gov/marine/offshores.php for more details. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near the coastal borders of Sierra Leone and Liberia, then runs southwestward to 04N16W. An ITCZ continues southwestward from 04N16W to 02S25W, then turns westward to 02N37W. Widely scattered showers are noted near and south of the trough from 03N to 05N between 10W and 15W. Scattered moderate convection is seen near and north of the ITCZ from the Equator to 04N between 16W and 31W. ...GULF OF MEXICO... A surface ridge extends southwestward from a 1027 mb high over the central US to a 1021 mb high at the western Bay of Campeche. A surface trough is causing patchy showers across the eastern Bay of Campeche. Moderate with locally fresh ENE to E winds and seas of 4 to 6 ft are present across the eastern and south-central Gulf, including the Florida Straits and eastern Bay of Campeche. Gentle to moderate E to ESE winds and 2 to 4 ft seas prevail for the rest of the Gulf. For the forecast, high pressure will dominate the Gulf waters through the week. Gentle to occasionally moderate winds and slight to moderate seas will prevail. ...CARIBBEAN SEA... Please see SPECIAL FEATURES section about an upcoming Gale Warning. The southwestern end of a weakening cold front reaches southwestward from central Cuba to near the Island of Youth, then continues as a stationary front to the Yucatan Peninsula. Patchy showers are evident up to 40 nm along either side of this boundary. Convergent trade winds are causing scattered showers near the northern Windward Islands and Panama coast. Fresh to strong NE to ENE winds and seas of 6 to 9 ft are noted at the south-central basin. Gentle to moderate NE to E winds and 3 to 6 ft seas exist at the north-central and southwestern basin, and near the ABC Islands and Yucatan Channel. Gentle ENE to E winds and seas at 2 to 4 ft prevail elsewhere in the Caribbean Sea. For the forecast, high pressure mentioned in the Special Features section will continue to support fresh to strong winds across the south-central Caribbean into the weekend. Gentle to moderate winds will prevail elsewhere. The aforementioned frontal boundary will gradually dissipate tonight into Tue. ...ATLANTIC OCEAN... Please see SPECIAL FEATURES section at the beginning about Significant Swells. A cold front extends southwestward from the north-central Atlantic across 31N59W to beyond the southeast Bahamas and Great Bahama Bank. Scattered showers and isolated thunderstorms are occurring near and up to 60 nm northwest of the front. Another cold front reaches southwestward from the western Azores across 31N35W to near 27N43W, then continues as a surface trough to 25N50W. Scattered showers are found up to 50 nm along either side of the front. Refer to the Monsoon Trough/ITCZ section for additional weather in the Atlantic Basin. Other than the Significant Swell area mentioned in the Special Features section, fresh to strong W to NW winds and seas at 7 to 11 ft are present behind the first cold front. Fresh to strong southerly winds and 6 to 8 ft seas are found near the second cold front, north of 27N between 26W and 35W. A surface ridge related to a 1018 mb high near 23N56W is supporting light to gentle winds and 7 to 11 ft seas in large northerly swell exist from 20N to 31N/cold front between 44W and southeast Bahamas. Near the Canary Islands, a surface ridge extending southwestward from a 1025 mb high southwest of Portugal is promoting gentle to moderate NE to E to SE winds and seas of 7 to 10 ft in large northerly swell are evident north of 20N between the Africa coast and 30W/second cold front. Near the Cabo Verde Islands, gentle to moderate NNE to NE winds and seas at 6 to 8 ft at moderate N swell are noted from 10N to 20N between the central Africa and 30W. For the tropical Atlantic, gentle with locally moderate NE to E winds and 5 to 7 ft seas dominate from the Equator to 20N between 30W and the Lesser Antilles. Light to gentle winds and 4 to 7 ft seas in mixed moderate swells prevail for the remainder of the Atlantic Basin. For the forecast W of 55W, the northern portion of the first cold front will continue moving eastward across the region through Tue, leaving a weakening stationary front extending to the Windward Passage by early Tue. Strong to near-gale force winds and very rough to high seas will accompany the front mainly north of 24N, through the early part of the week. Winds will diminish from west to east into midweek as high pressure builds in the wake of the front. Combined seas in excess of 8 ft may linger east of 70W through midweek due to associated northerly swell. $$ Chan