620 AXNT20 KNHC 140005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Mon Aug 13 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 2345 UTC. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 27W, from 08N to 20N. Widely scattered moderate to isolated strong rain showers are in the monsoon trough area, from 07N to 10N between 26W and 34W. It is possible that any precipitation may be more related to the monsoon trough than to just the tropical wave. An Atlantic Ocean tropical wave is along 47W from 08N to 21N, moving west at 10-15 kt. Isolated moderate rain showers are in the monsoon trough area, from 07N to 09N between 42W and 49W. A Caribbean Sea tropical wave is along 66W from 10N to 23N, relocated about 500 nm west of its previous position. Any precipitation near the wave axis may be more related to the ITCZ than the tropical wave. A Caribbean Sea tropical wave is along 76W/77W from 10N to 22N. Widely scattered moderate to isolated strong rain showers are between Jamaica and Cuba. It is possible that this precipitation may be more related to the current upper level cyclonic wind flow than the tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 14N17W to 10N23W to 09N40W. The ITCZ continues from 09N40W to 08N50W to 10N61W. Scattered moderate to strong rain showers are from 09N to 11N between 60W and 62W near Venezuela and Trinidad. Widely scattered moderate isolated strong rain showers are elsewhere from 08N to 12N between 58W and 64W. Isolated moderate to strong rain showers are elsewhere from 07N to 11N between 46W and 56W. Isolated moderate rain showers are elsewhere from 44W eastward. ...DISCUSSION... GULF OF MEXICO... An upper level cyclonic circulation center is over the Isthmus of Tehuantepec of southern Mexico. Upper level cyclonic wind flow covers the Gulf of Mexico south of 24N and 90W westward. A 1020 mb high pressure center is centered near 27N89W. Broad upper level anticyclonic wind flow spans the rest of the area. Widely scattered moderate isolated strong rain showers are from 26N to 29N between Florida and 91W. Isolated moderate rain showers are elsewhere north of 22N and east of 92W. A nocturnal trough will develop during the evening hours in the Yucatan Peninsula, before pushing offshore into the SW Gulf each night. A surge of fresh to occasionally strong NE to E winds will accompany this trough. The trough will become weaker by the middle of the week, allowing the winds to diminish. A surface ridge will support light to moderate E to SE winds across the remainder of the basin through Friday night. CARIBBEAN SEA... An upper level trough is spreading cyclonic wind flow across the Caribbean Sea from north of 14N and west of the Windward Passage including the Yucatan Peninsula and Central America. Isolated moderate to locally strong rain showers cover the area north of 15N between 75W and 90W. The monsoon trough is along 09N between 73W and 85W. Scattered moderate isolated strong rain showers are within 45 nm on either side of the line that runs from 09N80W at the coast of Panama, to 12N85W in south central Nicaragua. Surface high pressure north of the area will maintain fresh to strong winds in the south central Caribbean Sea through Tuesday. Earlier strong to minimal gale force winds along the coast of Colombia and in the Gulf of Venezuela, have begun to subside. The wind speeds and the sea heights in the Caribbean Sea will subside during the middle of the week, as the western Atlantic Ocean high pressure center gradually weakens. ATLANTIC OCEAN... Upper level cyclonic wind flow from an upper level trough covers the Atlantic Ocean from Cuba and Hispaniola northward and west of 70W. Isolated moderate to locally strong rain showers are in the area of upper level cyclonic wind flow. Upper level cyclonic wind flow associated with a trough covers the Atlantic from 22N northward between 35W and 60W. Isolated moderate to locally strong rain showers cover the Atlantic Ocean north of 28N between 45W and 56W. A low pressure center and a trailing surface trough are north of the area along 50W. A surface ridge extends from a 1022 mb high pressure center near 33N34W to 28N50W to a 1024 mb high pressure center near 30N63W, to the NW Bahamas. The surface ridge will remain in place during the next several days. This ridge will help to maintain fresh to locally strong winds along the northern coast of Hispaniola and approaches to the Windward Passage at night. Gentle to moderate anticyclonic wind flow will continue N of 23N, while mainly moderate easterly wind flow will prevail S of 23N. For additional information please visit http://www.hurricanes.gov/marine $$ Mundell