843 AXNT20 KNHC 180549 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Mar 18 2023 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Atlantic Significant Swell Event: A cold front extends from 31N40W SW to the NE Caribbean crossing near Guadeloupe in the Leeward Islands. Long period NW swell accompanies this front, currently peaking near 16 ft. Seas of 12 ft or greater are noted generally N of 27N W of the front to about 60W based on altimeter data and buoy observations. Fresh to strong winds are observed on either side of the front, particularly N of 28N and E of 56W. This swell event will continue to propagate across the forecast waters today, with seas subsiding below 12 ft by Sun morning as the front moves E of 35W. At that time, seas of 8 to 11 ft will continue to dominate most of the waters between 35W and 60W. Atlantic Gale Warning E of 35W: A strong pressure gradient between surface high pressure located N of the Madeira Islands and lower pressures over northern Africa will lead to the development of gale force winds in the region of Agadir Sat morning through Sat evening and in the Tarfaya region late Sat afternoon into Sat night. For more details, refer to the Meteo-France High Seas Forecast listed on their website https://wwmiws.wmo.int. Gulf of Mexico Gale Warning: A strong cold front extends from the western Florida Panhandle to near Poza Rica, Mexico. Behind this front, fresh to strong northerly winds are seen over the NW and west-central Gulf; while gale northerly winds are at the western Bay of Campeche, including the Veracruz area until early Sat morning. Rough seas are present in all areas. The front will reach from near Fort Myers, Florida to the eastern Bay of Campeche late Sat afternoon, spreading strong to near-gale force northerly winds to the north-central, northeastern and central Gulf. Frequent gusts to gale force are expected at the central Gulf by late Sat afternoon, which will expand into the eastern Bay of Campeche by Sun evening. In addition, winds offshore Veracruz, Mexico will reach again gale force by Sun morning. This front should reach from the Florida Straits to the Yucatan Peninsula Sun afternoon, bringing fresh to strong northerly winds to the western portions of the east-central and southeastern Gulf. Looking ahead, winds and seas will gradually diminish across the Gulf during the early to middle parts of next week as the front stalls and dissipates over the far northwest Caribbean. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and Offshore Waters Forecast at https://www.nhc.noaa.gov/marine/offshores.php for more details on these SPECIAL FEATURES. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic at the coast of Liberia near 06N11W then continues southwestward to 03N22W. The ITCZ continues westward from 03N22W to 02N30W to 00N50W. Scattered moderate to isolated strong convection is from the equator to 05N between 05W and 18W. GULF OF MEXICO... A strong cold front extends from the western Florida Panhandle to near Poza Rica, Mexico. Gale force winds are over the western Bay of Campeche behind the front. Please, read the Special Features section for information. A large area of showers and thunderstorms is ahead of the front mainly N of 25N affecting especially the NE Gulf, the Florida Bid Bend and N Florida. Gusty winds to gale force may occur in association with the strong thunderstorms. A well defined band of mainly low clouds is associated with the front. This cloudiness is banked up against the Sierra Madre Mountains in Mexico. For the forecast, please see the Special Features section for information about the cold front. CARIBBEAN SEA... A cold front extends over the NE Caribbean from near Guadeloupe in the Leeward Islands to S of Dominican Republic near 16N70W. The front is still generating some shower activity. Low level clouds with embedded showers and isolated thunderstorms are noted over parts of Hispaniola, between Jamaica and eastern Cuba and near the Cayman Islands where this activity is more concentrated. This could be associated with the remnants of the front. Fresh NE winds are noted north of the boundary. Seas of 6 to 8 ft in N swell are across the NE Caribbean Passages, including the Anegada and La Mona passages. High pressure over the western Caribbean combined with the Colombian low supports fresh to strong trade winds across the south-central Caribbean near the coast of Colombia, and in the Gulf of Venezuela. Mainly fresh winds are across the remainder of the central Caribbean, the Windward Passage and in the Gulf of Honduras. Seas in the aforementioned areas are 5-7 ft. Elsewhere, gentle to moderate trades prevail with seas of 4-6 ft. For the forecast, high pressure north of the area behind the front will support fresh to occasionally strong NE to E winds and moderate to occasionally rough seas across the eastern and central Caribbean into early next week. Large northerly swell will continue to impact Atlantic passages through Sat night. Fresh to strong E winds will continue to pulse off Colombia through mid week. Winds and seas will increase in the Yucatan Channel by Sun night as a cold front moves into the area. These winds and seas will gradually diminish through Tue as the stalled front dissipates. ATLANTIC OCEAN... A Gale Warning is in effect E of 35W for the regions of Agadir and Tarfaya. Please read the Special Features section for more details. As previously mentioned, a cold front extends from 31N40W SW to the NE Caribbean crossing near Guadeloupe in the Leeward Islands. Seas in excess of 12 ft are in the wake of the front. Please read the Special Features section for more information. High pressure of 1022 mb located near 28N67W dominates the western Atlantic, including SE Florida and the Bahamas. The associated ridge extends southward toward the Greater Antilles. Cold air stratocumulus clouds, and a gentle to moderate anticyclonic flow are seen under the influence of this system with seas of 5 to 7 ft E of the Bahamas. Fresh to locally strong E to SE winds are noted per scatterometer data over the Old Bahama Channel, including approaches to the Windward Passage. Fresh to strong southerly winds are on the western periphery of the ridge due to the pressure gradient between the high pressure and an approaching cold front from the west. These winds cover roughly the waters N of 28N E of Florida to about 75W. The remainder of the Atlantic forecast waters is dominated by another high pressure system of 1025 mb situated midway between the Azores and the Madeira Islands. Fresh to strong NE winds are occurring over the Canary Islands while fresh to locally strong winds are blowing over the Cabo Verde Islands. Seas of 8 to 12 ft in NW swell are observed per altimeter data across most of the waters N of 16N and E of 35W. Mainly moderate NE to E trades are blowing across the tropical Atlantic, with seas of 6 to 8 ft in NW to N swell prevailing between 35W and the Lesser Antilles, with the exception of an area with seas in the 8 to 10 ft range NE of the Leeward Islands. For the forecast W of 55W, a 1022 mb high pressure is centered between the Bahamas and Bermuda, building behind a cold front that moved south of the area into the northern Leeward Islands. This pattern will support moderate to occasionally fresh E to SE winds off Hispaniola through Sun. Large northerly swell west of 70W will subside through Sun. Meanwhile, expect fresh to strong southerly flow and building seas north of 29N between northeast Florida and Bermuda through Sat evening, ahead of a cold front moving off the northeast Florida coast Sat morning. The front will move east and stall from Bermuda to the Straits of Florida by early Mon. Looking ahead, seas will build north of the stalled front Mon through mid week with NE swell. $$ GR