000 AXNT20 KNHC 231811 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Fri Jul 23 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. ...SPECIAL FEATURES... As of 1800 UTC, a 1017 mb low pressure center near 30N79W, about 140 nm southeast of the Georgia coast. Disorganized numerous moderate to isolated strong convection is noted displaced to the east and south of the center due to strong upper level wind shear. Seas of 2-4 ft are occurring north of 28N and between 73W and 78W. Environmental conditions appear marginally conducive for additional development and a tropical depression could form over the next couple of days as the system meanders over the Gulf Stream, just offshore of the southeastern United States. Heavy Rainfall in Southern Central America: High moisture levels, persistent strong trade wind flow, and favorable conditions aloft will together support heavy rainfall for much of southern Central America through early next week. The heaviest rain is expected over the Caribbean coast of Costa Rica and southeast Nicaragua. These rains could cause significant flooding and mudslides in some areas. Currently, scattered moderate convection is noted along the Caribbean coast from northern Costa Rica through western Panama. ...TROPICAL WAVES... An Atlantic tropical wave is analyzed along 54W, south of 18N, moving W near 15 kt. A surface reflection is noted on the scatterometer satellite pass from 1300 UTC. Scattered moderate convection is noted within 100 nm east of the wave axis from 06N to 09N. A Caribbean tropical wave is analyzed along 68W, south of 22N, moving W at 15 to 20 kt. No significant convection is associated with this wave. Another Caribbean tropical wave is analyzed along 81W, south of 25N, moving W near 15 kt. No significant convection is associated with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean near Guinea-Bissau near 12N16W and extends to 11N42W. The ITCZ continues from 11N43W to 11N53W. Scattered moderate and isolated strong convection is noted within 300 nm south of these features between 42W and 55W. GULF OF MEXICO... The Bermuda High extends across Florida to a regional 1022 mb high pressure near 25N90W, which dominates the Gulf of Mexico. This system is keeping fair weather conditions in place, except for an area of showers and thunderstorms off the SW Florida peninsula. Recent scatterometer satellite data showed gentle winds prevailing across the basin. Seas 3-5 ft over the western Gulf, and 1-3 ft elsewhere. For the forecast, the Bermuda High will drift westward over the weekend as low pressure meanders offshore of the Atlantic waters of Florida, providing tranquil marine conditions across the Gulf through early next week. CARIBBEAN SEA... A recent scatterometer satellite pass showed strong to near gale force winds within 60 nm of the Colombia. Fresh to strong trades prevail elsewhere across the central and eastern Caribbean. Gentle to moderate winds are found elsewhere. Seas are 8-11 ft in the south-central Caribbean, 5-7 ft in the reminder of the central and eastern Caribbean, and 3-5 ft elsewhere. For the forecast, high pressure centered across the central Atlantic extends W-SW to central Florida and is combining with low pressure over N Colombia to support fresh to strong E winds over the central Caribbean. Fresh to strong winds are expected to continue across the central Caribbean through early Sat before the ridge weakens west of 75W. ATLANTIC OCEAN... An expansive 1028 mb high pressure near 34N43W is supporting mainly dry weather conditions across the basin. An area of fresh to strong winds is found south of 25N and west of 45W due to the pressure gradient between the strong ridge and lower pressures over South America. Seas within this region are 6-8 ft. Another area of fresh to strong NE winds surrounds the Canary Islands east of 25W, with winds reaching near gale force between the islands. Seas are 5-7 ft east of 25W. Elsewhere, gentle to moderate flow prevails and seas of 4-6 ft. For the forecast, moderate to fresh trades will prevail south of 25N through Sun. Low pressure along a frontal boundary will sink southward today through the weekend off the Georgia and NE Florida coasts. Environmental conditions are forecast to be marginally conducive for some gradual development over the weekend and into early next week while the system drifts offshore of the southeastern United States. Regardless of development, showers and thunderstorms and moderate to fresh winds can be expected over the weekend off the Florida coast as the ridge remains in place. $$ DELGADO/MORA