000 AXNT20 KNHC 241055 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sat Jul 24 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 0600 UTC surface analysis and satellite imagery through 0950 UTC. ...SPECIAL FEATURES... A 1015 mb low pressure centered over the waters east of Jacksonville, Florida, near 29.5N77.5W, and has a trough that extends W to near Daytona Beach, Florida and across the peninsula. This low continues to produce an area of showers and thunderstorms to the south and and east of the low, extending from NW Bahamas northeastward to beyond 31N74W. This system has become better organized since yesterday, and a tropical depression could Form over the weekend while the low meanders offshore or near the Florida peninsula. Interest in Florida should monitor the progress of this system. There is a medium chance for development in the next 5 days. Please read the latest Tropical Weather Outlook at hurricanes.gov, for more information. Heavy Rainfall in Southern Central America: High moisture content, persistent strong trade wind flow, and favorable conditions aloft will continue to 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 to strong convection is noted along the Caribbean coast from southern Nicaragua through western Panama. ...TROPICAL WAVES... A Caribbean tropical wave extends from the Atlantic waters north of Puerto Rico near 22N66W to 10N63W, moving W near 20 kt. Overnight scatterometer data and recent surface observations indicate a sharp surface trough associated with this wave and have required a repositioning farther to the W. A broad area of Saharan Air and a low level wind surge accompany this wave. Scattered squalls and thunderstorms have developed overnight between the islands of the NE Caribbean and 23N as the wave has interacted with an upper level low center to the north of Hispaniola. Other scattered showers and squalls extend south and southeastward across the Lesser Antilles and across the tropical Atlantic to 13N58W. A Caribbean tropical wave is along 75W, from the eastern end of Cuba to northwest Colombia, moving W at 15 to 20 kt. A few small clusters of showers are seen across the Windward Passage and the waters of the southeast Bahamas. Another Caribbean tropical wave is analyzed along 83W, north of 14N through western Cuba. No significant convection is associated with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean near Guinea-Bissau near 12N16W to 10N21W to 11.5N30W. The ITCZ continues from 11.5N30W to 10N46W to 11N54W. Scattered moderate convection is noted over the eastern Atlantic within 210 nm south of the trough between 29W and Africa, and from 06N to 14N between 48W and 58W. GULF OF MEXICO... Scattered moderate convection extends from the coastal waters of SE Louisiana to near the Tampa Bay, Florida area, and are associated with a surface trough that has moved southward into the NE Gulf. Across the northwest Gulf, a 1020 mb high pressure is centered near 27N92W, which is dominating the wind flow across much of the Gulf. To the southeast, a surface trough is analyzed along the west coast of the Yucatan Peninsula. Scattered moderate convection is noted west of the trough to 93W and south of 22N. Moderate S winds are noted along the Texas coast, west of the high pressure. Elsewhere, the high pressure is supporting light to gentle breezes and mostly 1 to 3 ft seas across the basin. The high pressure in the northwest Gulf of Mexico will meander and weaken through Mon as low pressure meanders offshore of the Atlantic waters of central Florida, and an associated trough across the NE Gulf drifts SW across the eastern Gulf. This is expected to produce tranquil marine conditions across the Gulf through early next week. CARIBBEAN SEA... A nearly stationary middle to upper low center remains north of Hispaniola near 21N79W and continues to interacting with the tropical wave moving across the E Caribbean to produce scattered squalls and a few thunderstorms across the waters of the NE Caribbean, from the Mona Passage southeastward to the waters of Guadeloupe and Dominica. Expect this activity to shift westward across the eastern Caribbean today. Overnight scatterometer data indicated a large area of fresh to strong trades winds over the south-central and southwest Caribbean, with the strongest winds off northeast Colombia. Seas are 5 to 9 ft in this area. These enhanced winds are occurring between the Atlantic high pressure ridge extending W-SW to the NW Bahamas, and low pressure over northern Colombia. Fresh winds are also noted just west of the Leeward Islands, south of Cabo Beata on the south coast of Hispaniola, and over the northern part of the Windward Passage. Elsewhere, generally moderate E winds and 3 to 5 ft seas are noted. This Atlantic ridge will weaken through early next week as the high shifts slowly NE and low pressure persists offshore of the Florida coast. This will lead to a gradual diminishing in the strength of tradewinds across the basin through tonight that will persist through early Wed. Look for scattered squalls and tstms across the NE Caribbean today and tonight associated with the fast moving tropical wave. ATLANTIC OCEAN... Please see the Special Features section above for information related to the area of low pressure off northeast Florida. A nearly stationary middle to upper low center remains north of Hispaniola near 21N79W and continues to interacting with the tropical wave moving across the E Caribbean, and is supporting scattered squalls and strong thunderstorms between 23N and Puerto Rico and the Virgin Island. Expect this activity to continue today east of 68W as the tropical wave moves across the eastern Caribbean and adjacent Atlantic waters to the north. Fresh to strong ESE winds and seas of 6-8 ft will prevail across the southeast waters today. Elsewhere, 1026 mb high pressure near 34N42W extends W-SW to the NW Bahamas and is supporting moderate to fresh tradewinds south of 25N, and mainly dry weather conditions across the remainder of the basin. Seas within this region are 6-8 ft. Fresh to locally strong E winds are active off the north coast of Hispaniola, reaching westward to the approaches of the Windward Passage, with 5 to 6 ft seas. 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. Moderate to fresh trades will prevail south of 25N through Sun. Low pressure near 29.5N77.5W 1015 mb has a trough that extends SW to central Florida. Environmental conditions are forecast to be marginally conducive for additional development of this low, with potential for it to become a tropical cyclone over the weekend while it meanders near or just offshore of Florida, then drifts W across Florida early next week. Scattered squalls and tstms associated with the fast moving tropical wave will move across the SE waters and north of the Greater Antilles through tonight. $$ Stripling