000 AXNT20 KNHC 091810 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Mar 9 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 1700 UTC. ...SPECIAL FEATURES... Western and Central Atlantic Significant Swell: Large, long-period N swell produced by gale to strong-gale winds associated with a 993 mb low pressure at the north-central Atlantic will move southward tonight through Sunday. This swell is going to create seas of 12 to 14 ft in the central Atlantic north of 27N between 36W and 57W from Sunday morning through late Monday morning. By Monday morning, a deep frontal low pressure system is expected to exit into the northwestern Atlantic near Nova Scotia. This system is forecast to produce even larger, long- period NW swell toward the western Atlantic, then spread into the central Atlantic by Wednesday. Anticipate seas to build steadily and reach 12 to 19 ft north of 27N between 53W and 72W by late Monday afternoon. These very rough to high seas will shift southeastward to north of 25N between 42W and 64W by Wednesday morning. Mariners need to monitor this developing situation 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 border of Guinea and Sierra Leone, then reaches southwestward to near 02N17W. An ITCZ continues westward from 02N17W across 00N30W to 00N45W. Scattered moderate convection is noted within 120 nm N of the ITCZ between 20W and 38W. Scattered moderate convection is seen south of the trough from the Equator to 02N between 11W and 16W, and up to 80 nm along either side of the ITCZ. ...GULF OF MEXICO... A cold front curves southwestward from the Florida Panhandle to near Tampico, Mexico. Scattered showers and isolated thunderstorms are occurring near and up to 50 nm northwest of the front. A surface trough extends northward from southeastern Mexico through a 1007 mb low at the central Bay of Campeche to just south of the cold front. Patchy showers are noted near the features. Fresh to strong N winds and seas at 5 to 8 ft are present behind the front across the northwestern and west-central Gulf. Fresh to strong NW winds and 4 to 6 ft seas are evident at the western Bay of Campeche. Gentle W to NW winds and seas of 2 to 4 ft are seen at the central Gulf, and the central and eastern Bay of Campeche. Moderate to fresh S to SW to NW winds and 3 to 6 ft seas prevail for the rest of the Gulf. For the forecast, the cold front will reach from Port Charlotte, Florida to Merida, Mexico by Sun morning before stalling and dissipating over the Yucatan Channel Mon. Fresh to strong northerly winds and moderate to rough seas are expected in the wake of the front. Conditions will improve early next week as high pressure builds in the wake of the front. ...CARIBBEAN SEA... A modest 1019 mb high north of Puerto Rico near 25N66W continues to sustain a trade-wind pattern for the entire basin.Fresh will locally strong ENE to SE winds and seas of 5 to 7 ft are exist at the south-central basin, and Gulf of Honduras. Fresh will locally strong E winds and seas at 6 to 7 ft are present near the ABC Islands. Gentle to moderate E to SE winds and 3 to 5 ft seas prevail elsewhere in the Caribbean Sea. For the forecast, the 1019 mb high will combine with Colombian Low to cause pulses of fresh to strong NE to E winds over the south- central Caribbean through Tue night, and in the Gulf of Honduras through tonight. Fresh to locally strong trades will also prevail near the ABC Islands through tonight. Gentle to moderate winds will prevail elsewhere. A weakening cold front will approach the Yucatan Channel and western Cuba late Sun. ...ATLANTIC OCEAN... Please read the Special Features section at the beginning about an upcoming Significant Swell Event for the western and central Atlantic. A modest frontal boundary reaches west-southwestward from the north-central Atlantic across 31N56W to near 28N70W, then turns northwestward to beyond 31N at 77W. Widely scattered showers are found up to 60 nm along either side of this boundary. A surface trough curves southeastward from 28N55W to a 1017 mb low at 25N50W, then turns northeastward to 26N48W. Enhanced by strong divergent flow aloft, scattered moderate convection is flaring up east of these features from 18N to 28N between 42W and 50W. Convergent trade winds are causing scattered showers near and just east of the Leeward Islands. Refer to the Monsoon Trough/ITCZ section for additional convection in the Atlantic Basin. Moderate to fresh southerly winds and seas at 6 to 8 ft are noted across the offshore waters of northeastern Florida. Otherwise, a 1019 mb high is promoting mostly gentle winds and 4 to 7 ft seas in moderate E swell north of 20N between 50W and the central Florida coast/Bahamas. At the central Atlantic, moderate to fresh SE to S winds and seas of 6 to 8 ft in moderate easterly swell are evident north of 20N between 38W and 50W. Farther east, a 1026 mb high near 31N38W is supporting light to gentle winds and 5 to 8 ft seas in moderate N swell north of 23N between 22W and 38W. Near the Canary and Cabo Verde Islands, Moderate to fresh NW to NE winds and seas of 7 to 10 ft in large northerly swell are noted from 12N to 23N/31N between the Africa coast and 22W/30W. For the tropical Atlantic, moderate to gentle easterly winds and seas at 6 to 10 ft in moderate to large NE swell exist from 05N to 20N/12N between 20W/30W and the Lesser Antilles. Light to gentle winds and 5 to 7 ft seas in mixed moderate swells prevail for the remainder of the Atlantic Basin. For the forecast W of 55W, the cold front portion of the aforementioned frontal boundary from 31N56W to 29N65W will continue to move to the east of the area through tonight. Another cold front will move off the northeast Florida coast tonight and reach from Bermuda to western Cuba Sun night. The portion of the front north of 22N will continue to the east of the region Tue, leaving a weakening stationary front extending to the Windward Passage by early Tue. Strong 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 mid week as high pressure builds over the western Gulf in the wake of the front. Combined seas in excess of 8 ft may linger east of 70W through mid week due to associated northerly swell. $$ Chan