000 AXNT20 KNHC 041810 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon Nov 4 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... Tropical Depression Eighteen: Newly formed Tropical Depression (TD) Eighteen is centered near 15.2N 76.9W at 04/1500 UTC or 170 nm south of Kingston Jamaica, and moving N at 8 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained winds are 30 kt with gusts to 40 kt. Seas are peaking from 8 to 10 ft near the center. Scattered heavy showers and isolated thunderstorms are occurring from 11N to 16N between 74W and 80W. TD Eighteen is expected to turn northwestward later today and this general motion should continue for the next few days. Steady strengthening is forecast, and the depression is anticipated to become a tropical storm later today and a hurricane by Wednesday. In addition, TD Eighteen will likely bring heavy rain across Jamaica, Cuba, the Cayman Islands and western Haiti. For the latest Eighteen NHC Forecast/Advisory and Public Advisory, visit www.hurricanes.gov for more information. Atlantic Ocean Significant Swell: Large easterly swell along with wind waves produced by strong to near-gale force ENE winds will continue is producing seas of 12 to 14 ft from 24N to 27N between 70W and the central and southwestern Bahamas. These conditions will expand northward to near 30N tonight. Starting Tue evening, both winds and seas should gradually subside. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and https://www.nhc.noaa.gov/marine/offshores.php for more details. Central America and Northwestern Colombia Heavy Rainfall: The formation of Tropical Depression Eighteen at the western Caribbean Sea has made it less likely for a strong low pressure to develop over Central America over the next few days. Therefore, the threat for heavy rain across Costa Rica, Panama and northwestern Colombia has decreased. However, heavy showers and strong thunderstorms remain possible. Brief flooding in low-lying and urban areas can still occur in heavy showers. Please refer to your local weather service for more information. ...TROPICAL WAVES... A central Atlantic tropical wave is near 48W from 13N southward, and moving westward at 5 to 10 kt. Scattered moderate convection is noted from 08N to 13N between 44W and 51W. ...MONSOON TROUGH/ITCZ... A monsoon trough stays mostly over the Africa continent. An ITCZ extends west-southwestward from just off the Guinea coast to 06N33W, then turns northwestward to 11N43W. Scattered moderate convection is noted near and up to 100 nm south of the ITCZ. ...GULF OF MEXICO... Please refer to the SPECIAL FEATURES section on newly formed Tropical Depression Eighteen. A surface ridge reaches southwestward from the Florida Panhandle to near Veracruz, Mexico. Fresh to strong SE winds and seas of 7 to 9 ft are present at the northwestern Gulf. Moderate to fresh E to SE winds and 4 to 6 ft prevail for the rest of the Gulf. For the forecast, the pressure gradient between the surface ridge and troughs over Mexico and the northwest Caribbean is supporting fresh winds and moderate seas across most of the Gulf. The forecast track of Tropical Depression Eighteen brings it into Florida Straits after midweek, therefore expect stronger winds and higher seas. ...CARIBBEAN SEA... Please refer to the SPECIAL FEATURES section on newly formed Tropical Depression (TD) Eighteen. An upper-level low and related upper-level trough are triggering scattered showers and isolated thunderstorms at the Gulf of Honduras and near the Cayman Islands. Converging southerly winds are producing scattered heavy showers and strong thunderstorms across the central basin. Outside the direct influence from TD Eighteen, gentle to moderate NW to N to SE winds with 3 to 6 ft seas are evident across the southwestern, central and eastern basin. Fresh to strong NE to ENE winds and seas at 6 to 8 ft prevail at the northwestern basin. For the forecast, Eighteen will strengthen to a tropical storm near 16.5N 77.6W this evening, move to 18.2N 79.0W Tue morning, 19.9N 80.7W Tue evening, strengthen to a hurricane near 21.7N 82.4W Wed morning, 23.4N 83.9W Wed evening, and 24.6N 85.1W Thu morning. Moderate winds and seas can be expected elsewhere into mid week. Large NE to E swell may enter the Atlantic passages of the northeastern Caribbean Thu into Fri. ...ATLANTIC OCEAN... Please refer to the SPECIAL FEATURES section for information regarding the significant swell across the western Atlantic. A stationary front stretches eastward from a 1010 mb low over the southeast Bahamas to a 1013 mb low near 24N53W. Widely scattered moderate convection is found near and south of these features to near 20N. A surface trough is generating similar convection east of Trinidad and Tobago from 10N to 13N between 52W and the Lesser Antilles. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional convection in the Atlantic Basin. Besides the strong to near-gale winds mentioned in the Special Features section, fresh to strong ENE to E winds with 6 to 8 ft seas are seen north of 20N between 60W and the Florida-Georgia coast. Farther east, gentle to moderate E to SE winds and seas of 5 to 7 ft are present north of 20N between 35W and 60W. For the tropical Atlantic from the Equator to 20N between 35W and the Lesser Antilles, gentle to moderate with locally fresh NE to E winds and 6 to 8 ft seas in mixed moderate swells prevail. For the forecast W of 55W, Tropical Depression Eighteen has formed in the central Caribbean Sea this morning. This depression is forecast to strengthen and move N and NW into the southeast Gulf of Mexico later this week, and could bring some increasing winds and seas to waters near and west of the Bahamas. Otherwise, a trough extends from Hispaniola to 26N63W. The pressure gradient between the trough and strong high pressure north of the region is supporting strong to near gale-force easterly winds and rough to very rough seas across the waters northwest of the trough. The trough will shift westward today, as building high pressure north of the area follows a cold front moving across the western Atlantic before becoming stationary and weakening along 22N by Wed. High pressure building to the north will support fresh to strong easterly winds and rough to very rough seas across the basin by mid week. $$ Chan