000 AXNT20 KNHC 141757 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Jul 14 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 1730 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 31W, from 14N southward, moving westward about 15 knots. Scattered moderate convection is where the wave meets the monsoon trough, and mainly from 07N to 10N between 30W and 32W. The northern portion of this wave is surrounded by SAL. A second, weaker Atlantic Ocean tropical wave is along 55W, from 15N southward, moving westward from 10 to 15 knots. Scattered moderate convection is from 10N to 12N between 53W and 58W. An active tropical wave passes through the Yucatan Peninsula, to western Central America, and into the eastern Pacific Ocean. The wave is moving westward from 10 to 15 knots. The wave is generating scattered rainshowers and isolated thunderstorms from 16N to 20N between 88W and 93W. The wave will move across the Yucatan Peninsula into the SW Gulf of Mexico today and tonight. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean near the Guinea- Bissau/Senegal border to 09N30W. The ITCZ continues from 09N32W to 07N53W. Clusters of moderate to strong convection are near and to the south of the monsoon trough from 06N to 10N from 25W eastward. Scattered moderate to isolated strong convection is from 05N to 08N between 31W and 50W. GULF OF MEXICO... A southeastern U.S.A. ridge extends across most of the northern Gulf of Mexico. A scatterometer satellite pass from 14/1400 UTC indicated 15 to 20 knots in the SW corner of the Gulf of Mexico. Gentle to moderate SE winds and sea heights ranging from 2 feet to 4 feet in the central Gulf. Scattered rainshowers and thunderstorms are in the far southwest Gulf, south of 22N and west of 93W. Scattered moderate rainshowers also are in the north central Gulf of Mexico. A surface ridge just north of the area will maintain gentle to moderate E to SE winds and slight to moderate seas across much of the Gulf through Friday. 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 Thu night. Looking ahead, a trough will move through the southeast Gulf on Friday and across the central Gulf on Saturday and Sunday, bringing a slight increase in winds and seas to the Straits of Florida Friday night into Saturday. CARIBBEAN SEA... An active tropical wave passes through the Yucatan Peninsula, to western Central America, and into the eastern Pacific Ocean. The wave is moving westward from 10 to 15 knots. The wave is generating scattered rainshowers and isolated thunderstorms from 16N to 20N between 88W and 93W. The wave will move across the Yucatan Peninsula into the SW Gulf of Mexico today and tonight. An upper level trough extends from the Atlantic Ocean, across the Greater Antilles, into the southern Caribbean Sea. Dry, subsident northerly flow aloft is suppressing showers and thunderstorms across much of the central and western Caribbean Sea. Scattered showers and isolated thunderstorms are within 60 nm of the coasts of Panama and Costa Rica. Fresh to strong trade winds are noted from 10N to 15W between 75W to 80W with 8 to 11 ft seas. Moderate to fresh E winds and 5 to 7 ft seas are noted elsewhere. High pressure north of the region is supporting strong tradewinds and rough seas over the south-central Caribbean. Fresh to strong NE to E winds are expected in the Gulf of Honduras through tonight. Winds and seas will diminish Thu and Fri as the high pressure weakens, although areas of fresh to strong winds will continue to pulse in the Gulf of Venezuela and near the coast of NE Colombia. Looking ahead, tradewinds and related seas will increase over the south-central Caribbean and slightly around the Leeward Islands Sat into Sun as another tropical wave reaches the eastern Caribbean. ATLANTIC OCEAN... Two tropical waves are moving westward between the west coast of Africa and the Lesser Antilles. Please refer to the Tropical Waves section for details. Anticyclonic wind flow covers most of the Atlantic basin. A 1025 mb high pressure center is near 31N41W. A large upper level trough is just to the north of Puerto Rico. A weak surface trough is located northeast of the Leeward Islands from 24N59W to 29N56W. A few showers are within 60 nm to the west of the trough. Scattered rainshowers also reaching the eastern Bahamas and Hispaniola. For the forecast for the waters west of 65W, a ridge extends just north of the area from roughly Bermuda to Georgia. This pattern will maintain gentle to moderate E winds across the basin. Looking ahead, winds and seas will build slightly Saturday south of 22N and north of the Leeward Islands as a tropical wave approaches the region from the east. Expect fresh to strong winds to pulse off Hispaniola by Saturday and Sunday. $$ SDR/MT/SK