000 AXNT20 KNHC 172251 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC SUN Jul 18 2021 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 1800 UTC surface analysis and satellite imagery through 2230 UTC. ...TROPICAL WAVES... An Atlantic tropical wave is near 35W from 21N southward and moving W at 5 to 10 kt. This wave remains embedded in the Saharan Air Layer, which dust and dry air suppressing all convection. Another tropical wave is crossing the Lesser Antilles into the eastern Caribbean this evening along 61W, from 20N southward. It is moving W at 10 kt. This wave is at the western edge of the Saharan Air Layer, thus no significant convection is occurring. A third tropical wave over the western Caribbean is near 81W from 16N southward across Panama and into the eastern Pacific. This wave is moving W at 10 to 15 kt. Scattered moderate convection is occurring between this wave and Central America. ...MONSOON TROUGH/ITCZ... A monsoon trough extends through the Gambia coast at 12N16W to 06N37W. Scattered moderate to isolated strong convection is seen from 04N to 10N between the African coast and 30W. ...GULF OF MEXICO... A surface trough that is moving W offshore the western Yucatan Peninsula inducing scattered moderate to locally strong convection in the eastern Bay of Campeche. Locally strong winds and seas at 4 to 6 ft are possible in these thunderstorms. Otherwise, a surface ridge extending southwestward from the Bermuda High across N Florida and the N Gulf is supporting mainly gentle ESE to SE winds and seas of 1 to 3 ft across the Gulf. For the forecast, the Bermuda High extends a ridge southwestward across the SE CONUS. As the ridge sinks southward during the next few days, tranquil conditions will prevail across the Gulf of Mexico. No tropical cyclone activity is expected over Gulf through at least Wed night. ...CARIBBEAN SEA... See Tropical Waves section for information on tropical waves in the far southwestern and far eastern portions of the basin. Otherwise, dry conditions prevail. Tight pressure gradient between the Atlantic ridge and the Colombian low continues to create fresh to strong trades and seas of 8 to 11 ft across the central and S central Caribbean. Gentle to moderate trades and seas of 2 to 4 ft are seen in the NW Caribbean. Moderate to locally fresh trades and seas of 4 to 6 ft prevail across the rest of the basin. For the forecast, the Bermuda High north of the area and lower pressure over N Colombia will support fresh to strong NE to E winds over the south-central Caribbean through most of the week. Expect an increase in speed and areal coverage from Mon night through Wed night while reaching as far west as the Hispaniola adjacent waters. Elsewhere, NE trades will become fresh to strong tonight and Sun night in the Windward Passage. Fresh to strong winds are also expected to pulse in the Gulf of Honduras Thu night. No tropical cyclone activity is expected through at least Thu. ...ATLANTIC OCEAN... A surface trough extends from Bermuda to the NW Bahamas. Scattered moderate convection is occurring in association with the through over and just north of the NW Bahamas. Refer to the Monsoon Trough/ITCZ section above for details on additional convection along the monsoon trough. The persistent surface ridge across the central Atlantic is sustaining light to gentle winds and seas of 2 to 4 ft N of 24N. Moderate to locally fresh trades and seas of 4 to 6 ft are present from 12N to 24N. Gentle to moderate trades and seas of 3 to 5 ft prevail for the rest of the Atlantic. For the forecast W of 65W, fresh to strong E winds will occur afternoons and early evenings north of Hispaniola for the next several days. Ridging associated with a weak Bermuda High will slowly sink southward to 27N by Wed, leading toward quiescent conditions across the remainder of the SW N Atlantic waters. No tropical cyclone activity is expected in the area through at least Thu. $$ KONARIK