000 AXNT20 KNHC 141746 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu Jul 14 2022 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. ...TROPICAL WAVES... A newly analyzed tropical wave that recently departed the African Continent is along 19W, from 19N southward, moving W at 10-15 kt. Scattered moderate isolated strong convection is from 09N to 12N east of the wave axis along 19W. Scattered moderate convection is from 09N to 12N between 19W and 24W. Convective activity with the tropical wave is likely being enhanced by the Monsoon Trough. A central Atlantic tropical wave has its axis along 42W from 16N southward, moving W at 10-15 kt. Scattered moderate convection is from 12N to 13N between 39W and 41W. A central Atlantic tropical wave has its axis along 52W from 09N to 22N, moving W at 15-20 kt. Scattered showers and tstorms are noted within 90 nm of either side of the southern portion of the wave axis. An eastern Caribbean tropical wave has its axis along 64.5W from 20N southward, moving W at 10-15 kt. Upper Air Sounding data from St. Maarten, which captured the tropical wave passage quite well, indicates that the Saharan Air Layer and a mid-level inversion are inhibiting convection with this tropical wave. ...MONSOON TROUGH/ITCZ... The Monsoon Trough extends from the border of Guinea-Bissau and Senegal near 12N17W to 08N30W. The ITCZ continues from 08N30W to 07N38W. Convection is described in the Tropical Waves Section. GULF OF MEXICO... At 1500 UTC, 1020 mb high pressure was centered near 27N85W. As a result of this feature and the subtropical Atlantic high pressure, ridging remains in force across the basin. Scattered moderate convection is in the NW Gulf from 25N to 27N between 94W and 96W. Additional scattered moderate convection is in the W Bay of Campeche from 19N to 21N between 94W and 96W. Gentle to moderate anticyclonic flow prevails with seas of 2-4 ft. The latest scatterometer pass showed locally fresh E winds in the Bay of Campeche. For the forecast, the aforementioned high pressure ridge will gradually weaken as it lifts northward to the southeastern U.S. by the upcoming weekend. This will allow for mainly gentle winds over the Gulf into early next week. Southerly winds increase to moderate speeds over the far western Gulf starting late on Sun. Otherwise, a weak upper-level low over the south-central Gulf will enhance showers and thunderstorms through today over portions of the southwestern and west-central Gulf. CARIBBEAN SEA... No significant convection is noted over the Caribbean at this time, as areas of Saharan Dust propagate westward through the basin. In the south-central Caribbean, the latest scatterometer data shows moderate to fresh trades. Seas are 6-7 ft in the central Caribbean, peaking at 8-9 ft within the area of strongest winds from 11N to 13N between 76W and 78W. In the E and W Caribbean, gentle to moderate trades prevail with 4-6 ft seas. For the forecast, the pressure gradient between the subtropical high and lower pressure over South America will weaken, allowing for the fresh to strong trade winds in the south- central Caribbean to diminish to mainly fresh speeds on Fri through Sat. The gradient will tighten again on Sun causing these winds to increase to fresh to strong Sun through Mon night while expanding in coverage over the central Caribbean. Fresh to strong east to southeast winds in the Gulf of Honduras will continue through tonight before diminishing Fri. Large NE to E swell is anticipated to begin impacting the tropical Atlantic Ocean zones this afternoon. The swell continue through Sat night, then subside by Mon ATLANTIC OCEAN... The subtropical Atlantic ridge centered north of the area remains in force across the basin. The latest scatterometer data depicts gentle anticyclonic winds are north of 25N, with moderate to fresh trades south of 25N. Seas are 4-7 ft across the basin, except locally 8 ft just NE of the Leeward Islands. A Tropical Upper Tropospheric Trough (TUTT) is apparent on satellite imagery, with the large upper level cyclonic circulation encompassing the Bahamas, Cuba, and South Florida. Some showers and tstorms are evident, mainly on the eastern half of the TUTT. For the forecast W of 55W, the aforementioned high pressure ridge will gradually shift northward during the next couple days. As the pressure gradient increases, the E trades south of 25N should strengthen to fresh from tonight through the weekend, pulsing to strong just north of Hispaniola. Large E swell will impact the waters south of 22N and east of the Bahamas from tonight through Sat before diminishing Sun into Mon. Expect for scattered showers and thunderstorms to increase over most of the western part of area, including the Bahamas, today into the weekend, as an upper- level low creates additional instability. Winds and seas may be higher in and near showers and thunderstorms. $$ Mahoney