468 AXNT20 KNHC 200003 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 803 PM EDT Sun Aug 19 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 2315 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 30W from 17N southward, moving W at 10-15 kt. Scattered showers are from 05N-10N between 27W-33W. An Atlantic Ocean tropical wave is along 46W from 20N southward, moving W at 10-15 kt. Scattered showers are within 90 nm of the wave axis S of 17N. A Caribbean Sea tropical wave extends from E Hispaniola to NW Venezuela, along 70W from 20N southward, moving W at 10-15 kt. Scattered showers are E of the wave axis from 14N-17N between 64W-68W. Similar showers are inland over NW Venezuela. A Caribbean Sea tropical wave is along 86W from 21N southward, in the western Caribbean Sea, moving W at 15 kt. Isolated moderate convection is within 120 nm of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Senegal near 13N17W, to 10N20W, to 09N23W, and to 09N43W. The ITCZ is along 07N46W to 06N53W, near the coast of French Guiana. Widely scattered moderate convection is from 06N-12N between 13W-26W. ...DISCUSSION... GULF OF MEXICO... Upper level cyclonic wind flow covers the S half of the Gulf of Mexico due to an upper level low centered over the Yucatan Channel. Upper level anticyclonic wind flow covers the N half of the Gulf of Mexico due to an upper level high centered over S Mississippi near 32N89W. Isolated moderate rainshowers are in the north central Gulf, between the Florida Panhandle and south central Louisiana. Isolated moderate rainshowers are along the Florida west coast from 27N85W southward and eastward into the Straits of Florida. Rainshowers are possible elsewhere south of 26N. A surface ridge is along 28N/29N at 75W in the Atlantic Ocean, crossing Florida along 28N/29N, reaching the north central Gulf waters, and beyond the middle Texas Gulf coast. A surface trough will develop along the western Yucatan Peninsula during the late afternoons, and then drift westward across the southwest Gulf waters during the overnight hours. The surface trough will be accompanied by a fresh east to southeast wind shift. The trough will dissipate along 96W during the late mornings. An east to west ridge will extend across the Gulf waters between 26N and 27N accompanied by gentle to moderate surface anticyclonic flow. CARIBBEAN SEA... An upper level low is centered over the Yucatan Channel. Upper level cyclonic wind flow covers the Caribbean Sea from 15N northward from Jamaica. Isolated moderate rainshowers cover the waters from 14N northward from 73W westward. An upper level inverted trough extends from Hispaniola into the SW corner of the Caribbean Sea. Scattered moderate to strong rainshowers are from 07N to 10N between 78W and 81W, around Panama. The monsoon trough is along 07N/08N from 74W in Colombia westward beyond at least 88W in the eastern Pacific Ocean. Strong nocturnal easterly trade winds are expected along the northwest coast of Colombia and in the Gulf of Venezuela through the middle of the week, with the strong winds expanding as far north as 15.5N on Monday night, and with the sea heights building to 10 feet. Strong east trade winds are forecast along the south coast of Hispaniola tonight. ATLANTIC OCEAN... An upper level trough is off the Florida NE coast. Scattered showers are W of 78W. An upper level low is centered over the central Atlantic near 32N57W. Scattered moderate convection is from 26N-29N between 56W-61W. A surface trough is along 46W/47W from 20N to 29N. Isolated moderate rainshowers cover the waters from 20N northward between 40W and 46W. A surface ridge will dominate the forecast waters during the next several days. A broad surface trough extending from 25N68W to 20N71W will continue westward, passing through the Bahamas on Monday and on Tuesday. Light to gentle winds are expected near the trough, and moderate to fresh trades are forecast south of 23N, except becoming locally strong along the north coast of Hispaniola during the late afternoon into the evening hours. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa