978 AXNT20 KNHC 102131 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Jul 11 2024 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 2015 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave is well west-southwest of the Cabo Verde Islands near 30W from 16N southward, and moving west around 15 kt. Hindered by Saharan Dust in the vicinity, no significant convection is seen near this wave. A central Atlantic tropical wave is near 43W from 23N southward, and moving westward around 10 kt. Influenced by dry Saharan Dust, no significant convection is seen near this wave. A western Atlantic tropical wave is near 58W from 25N southward, and moving westward at 15-20 kt. Being enveloped by much drier air at both low and mid levels, there is no significant convection. A western Caribbean tropical wave is near 82.5W from near western Cuba southward to just east of the eastern Nicaraguan and Caribbean Costa Rican coast. It is moving westward at 10-15 kt. Scattered to numerous showers and thunderstorms are found from 09N to 13N between 78W and the coast with additional convection inland, as well as just east of the Gulf of Honduras from 16N to 19N between 84W and 87W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic along the coast of southern Mauritania near 18N16W then curves southwestward through 12N24W to 13N37W to 11N45W. The ITCZ extends from 11N145W to 12N55W. Scattered moderate convection is observed from 07N to 11N between 43W and 48W. ...GULF OF MEXICO... A stationary front extends from the Florida Panhandle to 28N94W, then continues as a surface trough to the western Bay of Campeche. These features are triggering scattered showers and isolated thunderstorms in their vicinity. A surface ridge prevails to the east of the features. Gentle to locally moderate anticyclonic winds and seas at 2-4 ft prevail for the entire Gulf. For the forecast, the tail of a stationary front will dissipate over the NE Gulf of Mexico tonight and weak high pressure will develop, providing light to gentle variable winds across most of the basin north of 24N through Sun night. A surface trough will move off the Yucatan Peninsula into the Bay of Campeche every night through Sun, supporting moderate to fresh NE to E winds and moderate seas over the SW Gulf of Mexico. Otherwise, moderate to locally fresh easterlies are likely to develop across the Florida Straits and portions of the SE basin the next several nights. ...CARIBBEAN SEA... A broad subtropical ridge related to a Azores-Bermuda High north of 25N is supporting a trade-wind pattern across the entire basin. Aided by afternoon heating, convergent trades are triggering scattered showers and isolated thunderstorms over both western and eastern Cuba, Hispaniola, and Puerto Rico. Refer to the Tropical Waves section for additional weather in the Caribbean Sea. Fresh to locally strong NE-E winds and seas at 6-8 ft are evident at the south-central basin. Light to gentle winds and 3-5 ft seas in NE swell are found at the waters near Costa Rica and Panama. Gentle to moderate with locally fresh easterly winds and 3-5 ft seas prevail for the rest of the basin. For the forecast, fresh to strong trade winds will prevail across the central and portions of the SW Caribbean through Sun under the influence of the Azores-Bermuda High N of the region. The strongest winds will be in the south-central Caribbean and portions of the SW basin, including the Gulf of Venezuela and Colombia offshore waters. Strong winds in these regions may briefly reach near gale-force Fri night and seas will be rough to 10 ft. Gentle to moderate trades in the E Caribbean will reach moderate to fresh speeds Thu night into Sat as two tropical waves moves across the area. Gentle to moderate NE to E winds are forecast for the NW Caribbean, increasing to fresh speeds at night in the Gulf of Honduras, the lee of Cuba and the Windward Passage today through Fri. ...ATLANTIC OCEAN... A broad trough of low pressure located off the southeastern U.S. coast from near Charleston, South Carolina to 29N74W is currently producing scattered showers and thunderstorms across the Florida and the northern Bahamas offshore waters. Farther east, a pronounced upper-level low near 27N66W is generating widely scattered moderate convection from 23N to 29N between 61W and 74W. Refer to the Monsoon Trough/ITCZ section for additional convection in the Atlantic Basin. A broad subtropical ridge associated with a Azores-Bermuda High is promoting gentle to moderate winds across the basin west of 35W. Seas are 3-5 ft west of 65W, north of 29N between 25W and 65W, and also offshore of northeastern South America. Moderate to fresh NE winds prevail east of 35W, except fresh to strong from offshore Africa from near the Canary Islands to the Cabo Verde Islands. Seas are 6-8 ft across the area of fresh to strong winds, and 5-7 ft across the remainder of the waters. For the forecast west of 55W, environmental conditions associated with the aforementioned broad trough of low pressure located off the southeastern U.S. coast appear only marginally favorable for some additional development of this system over the next couple of days before it moves inland over the SE U.S. by this weekend. Regardless of development, moderate to fresh SE winds and moderate seas will affect the offshore waters between 64W and 80W through Fri night. Shower activity associated with this system will also prevail in this region through Thu night. Gentle to moderate E to SE winds elsewhere will reach moderate to fresh speeds tonight into Sat night due to a strengthening Azores- Bermuda High and the passage of two tropical waves over the eastern and central Caribbean. Locally strong winds and rough seas are likely for Puerto Rico and Hispaniola adjacent waters Thu night into Sat. $$ Lewitsky