000 AXNT20 KNHC 181756 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue May 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... ...METEO-FRANCE GALE-FORCE WIND WARNING OFF THE COAST OF MOROCCO... The surface pressure gradient between the 1026 mb Azores high pressure center that is near 35N22W and the comparatively lower surface pressures in West Africa is supporting gale-force winds in the METEO-FRANCE forecast area, that is called AGADIR. The sea heights there are ranging from 9 to 11 feet. The winds are forecast to diminish below gale-force at 19/0000 UTC. Please, refer to the Meteo-France High Seas Forecast, which is on the website: www.meteofrance.com/previsions-meteo- marine/bulletin/grandlarge/m etarea2, or the website: http://www.gmdss.org/bulletins/METAREA2.HIGH_SEAS_WARNING.0635.18 06352524849.html for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Guinea near 10N14W to 05N25W. The ITCZ continues from 05N25W to 03N36W to the NE coast of Brazil near 04N51W. Scattered moderate to strong convection is noted from 01N to 08N between 05W and 24W. Scattered moderate convection is noted within 200 nm of the ITCZ between 37W to 49W. GULF OF MEXICO... Weak surface ridging continues across the northeastern Gulf of Mexico due to high pressure located over the mid-Atlantic states. An ASCAT pass at 1500 UTC revealed fresh SE winds across most of the basin associated with the pressure gradient. Seas are 5 to 7 ft across the basin. A broad area of diffluence and middle level troughing over the Gulf continues to interact with the moist return flow at low levels and is producing clusters of strong convection across SW Louisiana and within 150 nm offshore SE of the Louisiana and Mississippi coastlines. A similar area of scattered convection is north of the Yucatan Channel from 22N-25N between 85W-88W. For the forecast, high pressure along the middle Atlantic coasts extending SW to the NE Gulf will remain generally stationary throughout the week. Winds will increase to fresh to strong late today through Fri as low pressure deepens across the Southern Plains and northern Mexico. CARIBBEAN SEA... High pressure across the NE Atlantic extends W-SW across the central Atlantic and weakly north of the NE Caribbean. The associated pressure gradient is producing moderate to fresh tradewinds across the basin. Generally fair weather prevails across most of the basin under the stable influence of an upper level ridge. Widely scattered moderate convection is seen across the coastal waters of Cuba, north of 20N, due to associated moisture from a stationary front extending from the central Bahamasacross central Cuba. Seas are 3 to 5 ft over most of the basin, the exception being off Colombia and NW Venezuela where seas are 5 to 7 ft. The monsoon trough extends into the basin from the eastern Pacific ocean through Panama. Scattered strong convection is within 100 nm offshore of Panama and NW Colombia. For the forecast, the high pressure across the NE Atlc will maintain moderate to fresh tradewinds across the basin through Wed. Trade winds will increase basin wide Wed night through Sat night as high pressure builds across the western Atlantic. Expect fresh to strong easterly winds in the Gulf of Honduras mainly at night through Thu night. ATLANTIC OCEAN A lingering cold front extends from 31N44W to 25N54W to 24N55W then becomes stationary to the central Bahamas to central Cuba. Scattered showers and thunderstorms are within 100 nm of the front. High pressure over the middle Atlantic coasts is supporting moderate to fresh E-NE winds to the north of the stationary front and west of 55W, where seas are 5 to 7 ft. East of 50W, winds ahead of the cold front are fresh to locally strong from the S-SW. For the forecast west of 65W, the stationary front will gradually become aligned E to W along 23N through Thu then sink southward to 21Nand dissipate by Fri night. The pressure gradient between high pressure off of Cape Hatteras and the frontal boundary will support an area of fresh to strong easterly winds N of the front and W of 68W Wed through Fri morning, with seas peaking around 11 ft E of the Bahamas late Wed through early Thu. Farther east, an elongated ridge axis extending from a 1026 mb high centered near 35N22W is allowing for gentle to moderate anticyclonic flow, except for near the Canary islands where NE winds become fresh. Moderate trades prevail elsewhere. Satellite imagery suggests an area of suspended African dust across the Tropical Atlantic south of 17N from the W African coast to 40W. $$ Mora