723 AXNT20 KNHC 270346 CCA TWDAT Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 804 PM EDT Sun Aug 26 2018 Corrected Atlantic Ocean section 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 0000 UTC surface analysis and satellite imagery through 2345 UTC. ...TROPICAL WAVES... A far eastern Atlantic tropical wave partially crosses the W African coast with its axis along 16W/17W from 04N to 20N, moving westward at 10-15 kt. The wave is embedded within the broad monsoonal trough region of W Africa. Moisture and convection within this region has increased during the past couple of days as observed on GOES-16 imagery. The latest imagery shows scattered moderate to strong convective clusters just east of the wave axis along to just inland the coast of Africa from 09N to 12N. Broken to overcast multilayer clouds with embedded scattered moderate convection are seen within 240 nm west and 120 nm east of the wave axis from 05N to 10N. A central Atlantic tropical wave has its axis along 45/46W from 03N to 20N, moving westward at 15 kt. This wave is surrounded by a rather stable and dry environment. Only isolated showers are possible within 120 nm on either side of the wave. A western Caribbean Sea tropical wave has its axis along 78W south of 20N, moving westward at 10-15 kt. This wave is moving into an area of pre- existing upper level cyclonic wind flow. The northern portion of the wave is helping to trigger off scattered moderate convection over eastern Cuba, while at the same time an upper-level low moves westward across central Cuba. Isolated showers are possible within 120 nm on either side of the wave. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through the coastal sections of Guinea-Bissau near 12N17W to 10N24W to 10N34W and to 09N445. No ITCZ was discernible. Aside from convective activity associated with the far eastern Atlantic tropical wave, scattered moderate isolated strong convection is within 240 nm south of the trough axis between 23W and 28W. Scattered moderate convection is within 180 nm south and 120 nm north of the trough axis between 34W and 38W. Similar activity is within 60 nm south of the trough axis between 29W and 32W. ...DISCUSSION... GULF OF MEXICO... An upper level trough extends from the coastal waters of Georgia and South Carolina, across NE Florida, to an upper-level low at 24N92W. At the surface, a westward moving trough extends from 28N88W to 22N88W. Upper-level cyclonic wind flow covers nearly the entire Gulf of Mexico east of 94W eastward. A second upper-level low is noted at the coast of Mexico near 20N97W. With these features in play along with a very moist and unstable atmosphere in place, abundant scattered shower and thunderstorm activity will continue over much of the basin through the next couple of days. 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. This trough, in combination with daytime heating and ample instability in place, has triggered off scattered moderate isolated strong convection over much of the Yucatan Peninsula. The activity is expected to diminish late tonight. A surge of moderate to fresh NE to E winds will accompany this trough. A weak surface ridge will remain over the rest of basin, with its associated gradient supporting a gentle to moderate wind flow regime. CARIBBEAN SEA... An upper level trough extends from a 21N63W Atlantic Ocean cyclonic circulation center, through the Mona Passage, to 16N72W just off the coast of Hispaniola, and eventually to 15N77W to the south of Jamaica. Isolated moderate rainshowers are from 14N northward from 80W eastward. Isolated to widely scattered showers are on the Atlantic Ocean side of Cuba between the SE Bahamas and 80W. An upper-level low moving westward is evident over central Cuba near 22N78W. Scattered moderate convection covers just about the entire island of Cuba. A shear axis extends from the upper-level low over Cuba to 19N83W and to near 17.5N86W. Plenty of atmospheric instability exists across the western Caribbean. This is resulting scattered showers and thunderstorms to exist west of 80W, including the Gulf of Honduras. In addition, the eastern segment of the eastern Pacific monsoon trough stretches eastward into the far southwestern Caribbean to the northwestern coast of Colombia. Scattered showers and thunderstorms are seen along and near this trough axis south of 11N and west of 75W. Fresh to strong winds, and building seas to 10 feet, will continue in the south central Caribbean Sea through Wed. A stronger tropical wave will approach the waters E of the Lesser Antilles on Tuesday, bringing fresh easterly winds and sea heights about 8 feet. The wave will enter the eastern Caribbean early on Wed, increasing the likelihood of scattered showers and isolated thunderstorms over much of the Lesser Antilles. ATLANTIC OCEAN...Corrected The southernmost point of a surface trough is 31N81W along the coast of SE Georgia. An upper level trough extends from NE Florida to a central Gulf of Mexico cyclonic circulation center. Scattered showers and thunderstorms are seen to the northwest of a line from 32N71W to 28N80W along the eastern coast of Florida. An upper level trough extends from 32N68W, to an upper-level low near 28N70W and to a second upper-level low over central Cuba. Isolated to widely scattered moderate rainshowers are elsewhere from 20N northward 66W and 80W. An upper level trough is at the western edge of the Canary Islands, from a 35N16W cyclonic circulation center to 24N21W. A second upper level trough extends from an upper-level low near 32N43W to 28N50W and to a second upper-level low near 21N63W. The trough continues toward the southern coast of Hispaniola. A surface trough extends from a 1022 mb low pressure center that is near 31N50W southwestward to near 29N52W. Isolated showers and thunderstorms are elsewhere to the NW of the line that passes through 32N38W to 24N50W to 18N62W. A central Bahamas surface trough is forecast to move across the area through Mon. Gentle to moderate winds will be associated with this trough. The wind speeds will pulse to fresh to strong at night just north of Hispaniola through Tue. A weak surface ridge will remain over the remainder of these waters, with its associated gradient supporting gentle to moderate E to SE wind flow. For additional information please visit http://www.hurricanes.gov/marine $$ Aguirre