472 AXNT20 KNHC 031204 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 804 AM EDT Fri Aug 3 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 0600 UTC surface analysis and satellite imagery through 1100 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 19W/20W from 20N southward. widely scattered moderate to isolated strong rainshowers are from 09N to 12N between Africa and 20W. scattered moderate to strong rainshowers are about 100 nm to the south of the monsoon trough, from 10N to 12N between 20W and 28W. An Atlantic Ocean tropical wave is along 42W/43W from 19N southward, moving W 10 to 15 knots. isolated moderate rainshowers are from 06N to 14N between 36W and 50W. some of the precipitation is possibly more related to the ITCZ. An Atlantic Ocean tropical wave is along 56W/57W from 19N southward, moving W 10 to 15 knots. isolated moderate rainshowers are from 06N to 13N between 50W and 60W. some of the precipitation is possibly more related to the ITCZ. A Caribbean Sea tropical wave is along 76W/77W from 21N southward, moving W 10 to 15 knots. The wave is moving into the area of a pre-existing area of upper level cyclonic wind flow, with a trough and a cyclonic circulation center. A tropical wave is along 93W/94W from 20N southward, from the SW corner of the Gulf of Mexico into the eastern Pacific Ocean. rainshowers are possible within 60 nm to 120 nm on either side of the tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Senegal and Gambia near near 13N17W, to 12N30W, and 13N39W. The ITCZ continues from 08N44W to 09N49W, and 10N56W. Precipitation: scattered moderate to isolated strong rainshowers, in general, are from 09N to 12N between Africa and 28W. Please refer to the TROPICAL WAVES section for more information about precipitation. ...DISCUSSION... GULF OF MEXICO... An upper level trough is in the NW corner of the Gulf of Mexico, in the Texas coastal waters. The upper level trough is associated with a frontal boundary that extends from SE Louisiana to east Texas and into south central Texas. A surface trough extends from south central Georgia, through SE Louisiana, toward the coast of Mexico near 24N. Precipitation: isolated moderate to locally strong rainshowers are in the Straits of Florida between 79W and 82W, around the periphery of the SE Cuba cyclonic circulation center. Widely scattered moderate to isolated strong rainshowers are to the north of the line that extends from 27N82W along the Florida west coast, to 23N90W, to 22N98W along the coast of Mexico. A surface trough is along the line from 23N94W to 17N95W in the Isthmus of Tehuantepec of southern Mexico. Widely scattered moderate to isolated strong rainshowers are from land to 23N between 90W and 95W. The current Alabama-to-south Texas surface trough will wander in the western Gulf of Mexico between 85W and 95W through Friday, and then it will dissipate. It is likely that widespread rainshowers with thunder may be in the vicinity of the trough, increasing in intensity by late afternoon and evening. A surface trough will form each day across the Yucatan Peninsula, and then move across the Bay of Campeche at night. Fresh to locally strong winds will be possible in the eastern waters of the Bay of Campeche from sunset to midnight. A surface trough extending from southern Louisiana to the western Bay of Campeche will shift W and inland through tonight. The northern extent of a tropical wave will move through the Straits of Florida tonight and across the southern Gulf this weekend. Surface troughs moving W from the Yucatan Peninsula will produce fresh to locally strong winds over the eastern waters of the Bay of Campeche from sunset to around midnight. Otherwise, high pressure ridging will prevail in the wake of the tropical wave. CARIBBEAN SEA... An upper level trough passes through Cuba near 22N80W, into the SW corner of the Caribbean Sea. Scattered moderate to strong rainshowers are from 11N to 13N between 80W and 86W, from the coastal waters into the southern half of Nicaragua. Upper level cyclonic wind flow also covers the NE part of the area, from 15N to 23N in the Atlantic Ocean between 60W and 70W. Comparatively drier air in subsidence is present in the area of cyclonic wind flow. The monsoon trough is along 08N/09N between 74W in Colombia and beyond 83W/84W in southern Costa Rica. Isolated moderate rainshowers are elsewhere in the SW corner of the Caribbean Sea, away from the scattered moderate to strong rainshowers that are with the upper level trough. Fresh to locally strong trade winds are expected in the central Caribbean Sea and in the Gulf of Honduras through Tuesday night. The strongest wind speeds will pulse to 30 knots near 12N74W during the overnight hours, where the sea heights occasionally will build to 10 to 12 feet. ATLANTIC OCEAN... An upper level trough extends from a 31N72W cyclonic circulation center, to a 21N80W cyclonic circulation center just off Cuba, to 11N83W in the SW corner of the Caribbean Sea. Isolated moderate rainshowers are in the Atlantic Ocean from 20N northward between 50W and 80W. A surface ridge extends from a 1022 mb high pressure center that is near 33N35W, to a 1026 mb high pressure center that is near 33N66W. The wind speeds will pulse to strong speeds near the northern coast of Hispaniola each night through Tuesday night. The trade trade winds, elsewhere across the region, will diminish gradually through early next week, as a ridge across the Atlantic Ocean weakens with a backdoor cold front moving southward. The front will dissipate into a trough through the end of the weekend. It is possible that weak low pressure may develop along the trough through early next week. A surface Ridge will develop by the middle of the week as the trough dissipates. For additional information please visit http://www.hurricanes.gov/marine $$ MT