521 AXNT20 KNHC 240003 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Mon Jul 23 2018 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...TROPICAL WAVES... A tropical wave is moving across the far east Atlantic with axis extending from 05N-20N along 30W, moving W at 10-15 kt. A large area of Saharan dust is noted along the wave mainly north of 10N. Widely scattered moderate convection is noted where the wave intersects the monsoon trough from 08N-11N between 25W-32W. A tropical wave is in the central Atlantic with axis extending from 05N-22N along 50W, moving W at 15 kt. This wave is on the leading edge of a large area of Saharan air, inhibiting large scale convection at this time. Scattered moderate convection is noted on the southern end of the tropical wave where it intersects the monsoon trough from 05N-09N between 41W-47W. A tropical wave in the western Atlantic with axis extends from 07N-21N along 62W, moving W at 15 kt. The wave is accompanied by Saharan dry air and dust, inhibiting any significant convection. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 16N16W to 09N26W to 08N40W. The ITCZ extends from 08N40W to the coast of South America near 07N58W. Besides the convection mentioned in the tropical waves section, scattered showers are within 120 nm either side of the remainder of the convergence zone axis. ...DISCUSSION... GULF OF MEXICO... A nearly stationary front extends from the Florida Panhandle at 30N84W to SE Louisiana near New Orleans, with scattered moderate to strong convection over water south of the front as a squall line from northern Florida south of Louisiana. strong winds and 6-7 ft seas are reported along the squall line. The remainder of the basin is under the influence of a surface ridge, anchored by a 1016 mb high centered over the Yucatan Channel near 21N85W. This feature is maintaining fair weather, light to gentle winds, and 1 to 3 ft seas across remainder of the basin. The cold front over the Florida Panhandle will be followed by another weak cold front that will move over the northern Gulf waters Tue night. This front will become stationary and weaken Thu. A surface trough will move off the Yucatan Peninsula into the Bay of Campeche each evening, accompanied by fresh nocturnal winds. Elsewhere, surface ridging will prevail. CARIBBEAN SEA... A tropical wave is entering the E Caribbean. See above. Widely scattered moderate convection is S of Cuba from 18N-20N between 76W-82W. Dry conditions persist elsewhere. Scatterometer data indicated fresh to strong trade winds over the south central Caribbean, mainly off Colombia. Maximum seas are estimated to be 8 to 9 ft. Seas are 2 to 3 ft in the northwest Caribbean, and 5 to 7 ft elsewhere. ATLANTIC OCEAN... Two more tropical waves are moving across the basin. Refer to the section above for details. Scattered moderate to isolated strong convection is over the northern Bahamas and adjacent waters related to divergent flow aloft. Gusty winds are possible in these thunderstorms. Moderate S to SW winds are noted west of 70W with 4 to 6 ft seas in open waters. A broad high prevails across the remainder of the basin, centered near 40N48W. The Atlantic high along with low pressure over the southeast U.S. will produce moderate to fresh southerly winds across the waters just offshore the central and northeast Florida through Wed. Moderate to fresh winds are also expected south of 22N, including approaches to the Windward Passage. Ridging will dominate the area most of the forecast period, with a surface trough reaching the E part of the region by Thu. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell