926 AXNT20 KNHC 261206 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 806 AM EDT Sun Aug 26 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 1145 UTC. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 28W from 05N to 20N, moving westward at 15 kt. Scattered moderate convection is within 30 nm of line from 12N28W to 11N34W, and within 30 nm of line from 06N26W to 05N28W to 04N32W. Isolated showers are elsewhere from 10N to 13N between 27W and 30W. Another eastern Atlantic tropical wave has its axis along 38W/39W from 04N to 20N, moving westward at 10-15 kt. Broken to overcast multilayer clouds along with scattered moderate isolated strong convection are noted where the wave axis crosses the monsoon trough, and to the south of the monsoon trough. The scattered moderate isolated strong convection is occurring from 05N to 07N between 35W and 37W. Scattered moderate isolated strong convection is within 30 nm of line from 11N34W to 11N38W, and within 30 nm of line from 11N39W to 11N44W. Scattered showers and isolated thunderstorms are seen along the monsoon trough within 120 nm east of the wave. A central Atlantic tropical wave has its axis along 55W from 03N to 19N, moving westward at 15 kt. Isolated showers and thunderstorms are within 60 nm either side of the wave south of 08N. A central Caribbean Sea tropical wave has its axis along 72W south of 19N to well inland S America, moving westward at 10-15 kt. Rather dry and stable conditions surround this wave. Isolated showers moving quickly westward are possible near this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from coast of Senegal near 14N17W, to 10N23W, 09N30W, 08N36W, and 07N39W. The ITCZ continues from 07N39W to 05N45W and 05N50W. Aside from convection associated with the tropical waves, increasing scattered moderate isolated strong convection is south of the trough axis within 30 nm of a line from 06N12W to 07N20W to 07N26W, and also within 60 nm of 08N145W. ...DISCUSSION... GULF OF MEXICO... A surface trough is in the NE corner of Florida. An upper level trough extends from the coastal waters of Georgia and South Carolina, across NE Florida, to a Gulf of Mexico 26N88W cyclonic circulation center. Upper level cyclonic wind flow covers nearly the entire Gulf of Mexico, from 94W eastward. A second upper level cyclonic circulation center is at the coast of Mexico near 20N97W. Isolated moderate rainshowers span the Gulf of Mexico. A surface trough will develop during the evening hours in the Yucatan Peninsula, before pushing offshore into the SW corner of the Gulf of Mexico each night. A surge of moderate to fresh NE to E winds will accompany this trough. A surface ridge will dominate the rest of the Gulf waters, supporting a gentle to moderate wind flow. CARIBBEAN SEA... An upper level trough extends from a 21N63W cyclonic circulation center, to a second cyclonic center that is near 17N71W, just off the coast of Hispaniola, and eventually to 15N77W in the Caribbean Sea. A surface trough is along 26N71W 23N72W 20N73W just off the coast of Haiti and near the northern part of the Windward Passage. An upper level inverted trough is along 85W/86W, in Nicaragua and Honduras. The monsoon trough is along 08N/09N from 75W in Colombia westward, beyond southern Costa Rica. Isolated moderate rainshowers are from 13N northward from 77W westward. Scattered to numerous moderate to strong rainshowers are from 06N to 10N between 74W and 80W, in Colombia and Panama. Widely scattered moderate to isolated strong rainshowers are elsewhere from 13N southward from 78W westward. Fresh to strong winds, and building seas to 10 feet, will prevail in the south central Caribbean Sea through Wednesday. A tropical wave, that is moving across the central part of the basin, will continue to generate rainshowers with thunder across Cuba today and on Monday. A second tropical wave will approach the waters E of the Lesser Antilles on Tuesday, bringing fresh easterly winds and sea heights reaching about 8 feet. The wave will enter the E Caribbean Sea on Wednesday. It will support heavy rainshowers with thunder in the NE corner of the basin. ATLANTIC OCEAN... A surface trough is in the NE corner of Florida. An upper level trough extends from an Atlantic Ocean 29N70W cyclonic circulation center, to a second cyclonic circulation center that is near 23N77W, between Cuba and the Bahamas. The southernmost part of a stationary front passes through 33N77W to 31N81W near the coast of SE Georgia. A narrow NE-to-SW oriented upper level trough extends from 32N81W near the South Carolina/Georgia border, across NE Florida, to 28N83W in the NE corner of the Gulf of Mexico, to 23N88W in the Gulf of Mexico. An upper level cyclonic circulation center is near 23N75W, on top of the central Bahamas. A second cyclonic circulation center is near 29N67W. Widely scattered moderate to isolated strong rainshowers are to the west of the line that passes through 33N70W 27N75W 22N76W. Isolated moderate rainshowers are elsewhere from 70W westward. Isolated moderate rainshowers are in the Gulf of Mexico from 94W eastward. An upper level trough extends from a 35N16W cyclonic circulation center, acrosss the Canary Islands, to 26N20W. A second upper level trough extends from a 32N43W cyclonic circulation center, to 28N50W, to a second cyclonic circulation center that is near 21N63W. The trough continues to a third cyclonic circulation center that is near 17N71W, just off the coast of Hispaniola, and eventually to 15N77W in the Caribbean Sea. A surface trough is along 26N71W 23N72W 20N73W just off the coast of Haiti and near the northern part of the Windward Passage. A surface trough, that is in the SE Bahamas, is forecast to move across the area through Monday. Gentle to moderate winds will be associated with this trough. The wind speeds will pulse to fresh to strong at night just N of Hispaniola through Thursday. A weak surface ridge will dominate the rest of the forecast area, supporting gentle to moderate E to SE wind flow. For additional information please visit http://www.hurricanes.gov/marine $$ MT