000 AXNT20 KNHC 122336 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Jul 12 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 2300 UTC. ...TROPICAL WAVES... An Atlantic tropical wave extends its axis along 38W from 12N southward and moving W at 10 to 15 kt. Scattered showers are noted along 08N between 37W-40W where the wave meets the monsoon trough. Another Atlantic tropical wave extends its axis along 50W from 10N southward and moving W near 10 to 15 kt. Scattered moderate convection is noted along 08N where the wave meets the ITCZ. A central Caribbean tropical wave extends its axis along 74W and south of 22N, moving W at 10 to 15 kt. Aided by upper-level divergent winds, scattered showers prevail across the northern portion of the wave affecting the Windward Passage, Hispaniola and eastern Cuba. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea-Bissau near 12N16W to 08N41W. The ITCZ then continues from 08N41W to 07N50W. In addition to the convection listed in the Tropical Wave section above, scattered moderate convection is evident near the monsoon trough from 07N to 12N between 15W and 20W. Scattered showers is noted south of 10N between 20W-30W and within 60 nm of the boundaries. ...GULF OF MEXICO... A surface ridge extends west-southwestward from northern Florida across the northern Gulf to South Texas. Latest scatterometer pass depicts gentle to moderate E to SE winds over most of the basin. Seas are mainly 2 to 4 ft. A few showers and thunderstorms are noted over the northwestern Gulf, the Straits of Florida, and over the warmer Loop Current of the south-central Gulf. For the forecast, surface ridge just north of the area will maintain gentle to moderate winds and slight to moderate seas across much of the Gulf through Fri. A surface trough will develop each day over the Yucatan and shift westward into the SW Gulf. This will support fresh to occasionally strong winds off the northwest Yucatan Peninsula and eastern Bay of Campeche during the overnight hours through mid week. ...CARIBBEAN SEA... Please refer to the section above for details on the tropical wave moving across the basin. Scatterometer data depicts fresh trades across most of the eastern and central Caribbean, with locally strong winds in the south-central Caribbean offshore of Colombia. Maximum seas are estimated to be 10 ft in the south-central Caribbean, mainly off the coast of Colombia, and 6 to 8 ft over the eastern Caribbean where fresh tradewinds follow the tropical wave moving across the basin. Moderate E to SE winds and 3 to 5 ft seas are noted over the northwest Caribbean. In addition to the convection mentioned in the Tropical Wave section, scattered moderate convection is ongoing off Costa Rica and eastern Nicaragua west of 80W. For the forecast, the tropical wave in the central Caribbean will move west of the basin the middle of the week. High pressure centered north of the region will support strong tradewinds and building seas into Wed, including strong nocturnal NE winds across the Windward Passage Tue night into Wed. Winds and seas will diminish through Fri. ...ATLANTIC OCEAN... Please see the Tropical Waves and Monsoon Trough/ITCZ sections above for information on convection across the basin. A surface ridge extends from the central Atlantic across Bermuda to the central Florida coast. This pattern is supporting gentle to moderate E to SE trade winds north of 25N west of 35W with 3 to 5 ft seas over open waters. Fresh trades are noted south of 25N west of 35W to 60W with 6 to 9 ft seas. Fresh to locally strong E winds are south of 25N and west of 60W over waters surrounding the Greater Antilles with 4 to 6 ft seas. Divergence aloft associated with an upper low now centered over the west Atlantic is supporting scattered moderate convection mainly west of 75W. To the east, another upper level low is centered near 28N53W and it is reflected at the surface as a trough along 50W. Scattered showers are noted along and west of the trough north of 25N between 50W and 59W. For the forecast, the surface ridge will lift north to along 32N through Tue. Strong winds will continue to pulse off Hispaniola and into the Windward Passage Tue night into Wed. Winds and seas will diminish across the region through Fri as the area of high pressure weakens. $$ ERA