324 AXNT20 KNHC 170628 RRA TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Jul 17 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 31W, from 22N southward, moving westward 10 knots. Precipitation: any nearby precipitation is mostly related to the monsoon trough/ITCZ. Any earlier precipitation that may have been associated with this wave has diminished, partially due to dry and dusty Saharan Air Layer that has been present in the vicinity. An Atlantic Ocean tropical wave is along 55W, from 20N southward, moving westward 15 to 20 knots. Dry and dusty Saharan Air Layer also has been suppressing precipitation. Precipitation: Isolated moderate is from 09N to 17N between 46W and 60W. A Caribbean Sea tropical wave is along 74W/75W, from 16N southward, moving westward 15 knots. Precipitation: numerous strong is within 60 nm to the east of the tropical wave, and within 100 nm to the west of the tropical wave, in Colombia from 05N to 10N. Scattered moderate to widely scattered strong is in Colombia and Venezuela, within 150 nm to the east of the tropical wave from 08N to 11N to the west of Lake Maracaibo in Venezuela, and within 180 nm to the west of the tropical wave from 05N to 07N. A Caribbean Sea tropical wave is along 87W/88W, from 21N at the northern part of the Yucatan Peninsula southward, moving westward 10 to 15 knots. The wave passes through the NW corner of the Caribbean Sea, through Honduras, into the eastern Pacific Ocean. Precipitation: widely scattered moderate to isolated strong is within 240 nm on either side of the tropical wave, from 16N in the NW Caribbean Sea, to just to the north of the northern coast of the Yucatan Peninsula, to the western sections of the Yucatan Peninsula, and in the eastern half of El Salvador. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal border areas of Senegal and The Gambia, to 08N30W. The ITCZ is along 07N32W 04N47W. Precipitation: widely scattered moderate to isolated strong is within 240 nm of the coast of Africa, from 04N to 15N between 10W and 20W, and within 240 nm to the south of the monsoon trough and the ITCZ between 22W and 35W. ...GULF OF MEXICO... Precipitation: Isolated to widely scattered moderate is in the coastal waters of western Florida from 25N to 29N, and in the SW part of the area from 21N to 24N between 92W and 94W. An upper level inverted trough is along 90W, according to the GFS model. A surface ridge passes through 31N78W in the Atlantic Ocean, toward the west central Gulf of Mexico, toward the coast of Mexico near 22N98W. Gentle winds, with sea heights of 1 foot to 3 feet cover most of the Gulf. Moderate winds are occurring in the Florida Straits and in the adjacent waters off western Cuba. Surface ridging over SE CONUS, extending to the Gulf of Mexico, will support mainly moderate to locally fresh return flow through Sun night. The wind speeds will diminish to gentle to moderate on Monday, and continue through the middle of next week. ...CARIBBEAN SEA... A Caribbean Sea tropical wave is along 74W/75W, from 16N southward, moving westward 15 knots. Precipitation: numerous strong is within 60 nm to the east of the tropical wave, and within 100 nm to the west of the tropical wave, in Colombia from 05N to 10N. Scattered moderate to widely scattered strong is in Colombia and Venezuela, within 150 nm to the east of the tropical wave from 08N to 11N to the west of Lake Maracaibo in Venezuela, and within 180 nm to the west of the tropical wave from 05N to 07N. A Caribbean Sea tropical wave is along 87W/88W, from 21N at the northern part of the Yucatan Peninsula southward, moving westward 10 to 15 knots. The wave passes through the NW corner of the Caribbean Sea, through Honduras, into the eastern Pacific Ocean. Precipitation: widely scattered moderate to isolated strong is within 240 nm on either side of the tropical wave, from 16N in the NW Caribbean Sea, to just to the north of the northern coast of the Yucatan Peninsula, to the western sections of the Yucatan Peninsula, and in the eastern half of El Salvador. Fresh to locally strong trade winds, and sea heights that range from 6 feet to 8 feet, are in the south central Caribbean Sea. Moderate to locally fresh winds, and sea heights that range from 5 feet to 7 feet, cover the rest of the area. The Bermuda High north of the area and lower pressure over N Colombia continue to support fresh to strong NE to E trades over the S central Caribbean and portions of the SW basin. These winds will continue through early next week and increase in speed and areal coverage Mon night through Wed night. Otherwise, NE trades will become fresh to strong Sat night and Sun night in the Windward Passage. ...ATLANTIC OCEAN... A surface trough extends from just to the west of Bermuda, to the 28N75W. Precipitation: isolated moderate is within 120 nm on either side of the surface trough. Broad surface anticyclonic wind flow covers the rest of the Atlantic Ocean from 22N northward between Africa and 70W, away from the tropical waves. A 1030 mb high pressure center is near 39N43W. A surface ridge passes through 31N78W, toward the west central Gulf of Mexico. Light to gentle winds, and sea heights that range from 3 feet to 4 feet, cover the areas that are N of 23N from 35W to the Georgia/Florida coastline. Gentle to moderate trades and seas of 4 to 6 ft prevail from 11N to 23N between 26W and the Lesser Antilles, and also near the Canarias Islands from 24N northward between the coast of Africa and 26W. Light to gentle E to ESE trades and seas of 3 to 5 ft are seen for the rest of the basin. Surface ridging over SE CONUS extending to the gulf will support maily moderate to locally fresh return flow through Sun night. Winds will diminish to gentle to moderate Mon and continue through the middle of next week. $$ mt