046 AXNT20 KNHC 251755 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 155 PM EDT Sat Aug 25 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 25W/26W from 20N southward. Isolated moderate rainshowers are from 10N to 13N between 27W and 30W. An Atlantic Ocean tropical wave is along 34W/35W from 19N southward. This wave was added to the 25/1200 UTC map analysis based on long loop satellite imagery and computer model diagnostics. Broken to overcast multilayered clouds and possible rainshowers cover the area that is from 14N to 24N between 30W and 40W. An Atlantic Ocean tropical wave is along 52W/53W from 19N southward. Rainshowers are possible from 14N to 21N between 50W and 62W. A Caribbean Sea tropical wave is along 70W/71W from 18N southward. This wave is moving into an area of pre-existing upper level cyclonic wind flow. Rainshowers are possible within 120 nm on either side of the wave. A Caribbean Sea tropical wave is along 86W/87W from 20N southward, passing through Honduras and Nicaragua. Broad upper level cyclonic wind flow spans the western Caribbean Sea, with upper level cyclonic circulation centers and troughs. Widely scattered moderate to isolated strong rainshowers are in the waters that are from 80W westward. Isolated moderate rainshowers are elsewhere from the Windward Passage westward. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Senegal near 14N17W, to 10N23W, 09N30W, 08N36W, and 07N39W. The ITCZ continues from 07N39W to 05N45W and 05N50W. Precipitation: widely scattered moderate to isolated strong rainshowers are from 04N to 11N between 30W and 44W, and from 05N to 07N between 50W and 53W. Isolated moderate rainshowers are elsewhere from 13N southward from 60W eastward. ...DISCUSSION... GULF OF MEXICO... 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. 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 an Atlantic Ocean 23N62W cyclonic circulation center, into the NE corner of the Caribbean Sea near 18N63W and 16N70W. Isolated moderate rainshowers are from 70W eastward. An upper level inverted trough extends from the SW corner of the Caribbean Sea, across Nicaragua and Honduras, to the southern half of the coast of the eastern side of the Yucatan Peninsula. Widely scattered moderate to isolated strong rainshowers are in the waters that are from 80W westward. Isolated moderate rainshowers are elsewhere from the Windward Passage westward. Fresh to strong winds and building seas to 9 or 10 ft will prevail in the south-central Caribbean Sea through the forecast period. Tropical waves will continue to move across the basin, elsewhere, producing some convective precipitation and little impact in winds and seas. It is possible that the wind speeds and the sea heights may be higher near thunderstorms. ATLANTIC OCEAN... 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 34N18W cyclonic circulation center, to 34N35W, to a second cyclonic circulation center that is near 29N46W. The trough continues to a third cyclonic circulation center that is near 23N62W, into the NE corner of the Caribbean Sea near 18N63W and 16N70W. Isolated moderate rainshowers are within 300 nm on either side of the trough from 27N northward between 40W and 55W, and elsewhere from 20N northward between 50W and 72W. A surface trough is along 27N67W 24N70W 20N72W to the north of Hispaniola and at the SE end of the Bahamas. A surface trough, that is near the SE Bahamas, is forecast to move across the area through Monday. Gentle to moderate winds will be associated with this trough. Winds will pulse to fresh to strong during the evening and nighttime hours just N of Hispaniola through the middle of next week. A surface ridge will dominate the rest of the forecast area, supporting a gentle to moderate anticyclonic flow. For additional information please visit http://www.hurricanes.gov/marine $$ MT