000 AXNT20 KNHC 181757 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 PM EDT MON JUL 18 2016 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 1715 UTC. ...TROPICAL WAVES... Tropical wave in the east Tropical Atlantic extends from 13N39W to 4N35W moving west-southwest near 20 kt over the past 24 hours. Wave is becoming tilted and coincides with a well defined 700 mb trough as depicted in the global models and within a surge of deep moisture as seen on the SSMI Total Precipitable Water imagery. Clusters of scattered moderate convection are within 330 nm east and 210 nm west of the tropical wave. Tropical wave in the west Tropical Atlantic is broad with a mean axis extending from 22N55W to 9N54W moving west near 10 kt over the past 24 hours. Wave has become tilted with a southern vorticity center near 12N54W moving closer to 5 kt over the past 24 hours. Wave coincides with a 700 mb trough south of 16N as depicted in the global models and within a surge of moisture as seen on the SSMI Total Precipitable Water imagery. Isolated showers are within 75 nm of the wave from 11N-14N, otherwise no associated deep convection. Tropical wave in the west Caribbean extends along 82W/83W south of 18N to across Costa Rica into the east Pacific region moving west near 10 kt over the past 24 hours. Wave coincides with a 700 mb trough as depicted in the global models and is embedded within a surge of deep moisture as seen on the SSMI Total Precipitable Water imagery. Wave is enhancing the activity in the southwest Caribbean. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 19N16W and continues south of the Cape Verde Islands along 12N24W 8N312W 7N36W to 5N40W where the ITCZ begins and continues along 3N43W to South America near 2N51W. Scattered moderate to isolated strong convection is within 90 nm along the coast of Africa from 6N-10N. Clusters of scattered moderate convection are within 120 nm of line from 8N15W to 6N26W. ...DISCUSSION... GULF OF MEXICO... An upper ridge anchored over Louisiana and Arkansas extends over the Gulf waters this afternoon. An upper trough extends from an upper low along the north coast of Cuba to the Yucatan peninsula. This is producing a diffluent environment over the east Gulf to generate scattered showers and isolated thunderstorms north of 25N between 84W-90W with isolated showers and possible thunderstorms south of 25N east of 89W through the Straits of Florida. Lingering scattered showers and isolated thunderstorms are in the west Bay of Campeche south of 20N between 93W-96W. A surface ridge extends from the west Atlantic across the southeast CONUS to central Texas. The surface ridge will persist through the week. CARIBBEAN SEA... An upper low is centered along the north coast of Cuba near 23N78W and extends a trough axis westward over the north Yucatan peninsula. Clusters of scattered showers and isolated thunderstorms are north of 19N west of 75W to the coast of the Yucatan peninsula and inland over Cuba. An upper ridge axis extends from Guatemala southeast to Colombia. This is providing difflunce aloft and coupled with the tropical wave along 82W/83W and the monsoon trough that extends from Colombia to Costa Rica along 9N/10N are generating scattered showers and isolated thunderstorms south of a line from Nicaragua near 15N83W along 15N79W to Colombia near 11N75W. A surface trough extends along 63W from the central Atlantic to across the northern Leeward/ Virgin Islands near 17N. Isolated showers over the Leeward/ Virgin Islands are associated with the leading edge of a broad tropical wave that the mean axis is east of the Lesser Antilles. The tight pressure gradient between the west Atlantic surface ridge and the lower pressure over South America is producing fresh to strong trade winds across the south-central Caribbean that will continue through the week. The tropical wave in the west Caribbean will move inland across Central America later this afternoon. The tropical wave east of the Lesser Antilles will enter the east Caribbean early Wednesday then into the central Caribbean through early Thursday. ...HISPANIOLA... Isolated showers and possible isolated thunderstorms are developing over south portion of the island leaving clear skies across the remainder of the island. Afternoon or evening showers and thunderstorms will be possible through Thursday. The tropical wave east of the Lesser Antilles will enter the Caribbean early Wednesday and could bring more showers and thunderstorms to the island Thursday and Friday. ATLANTIC OCEAN... The upper low is along the north coast of Cuba near 23N78W covering most of the west Atlantic with cyclonic flow with an upper ridge axis along 32W/33W. This is providing difflunce aloft to generate scattered showers and isolated thunderstorms north of 28N west of 70W to over the southeast CONUS. A surface trough extends from 26N71W across the Turks and Caicos to 20N72W with scattered showers and isolated thunderstorms within 90 nm either side of the trough axis. A second surface trough is to the southeast extending along 63W south of 24N to across the Leeward/Virgin Islands. This appears to be a northern vorticity center associated with the tropical wave just east of the Lesser Antilles. Scattered showers and isolated thunderstorms are from 20N-23N west of the trough axis to 67W with isolated showers and thunderstorms from 17N-22N east of the wave axis to 60W. Otherwise, high pressure dominates the remainder of the Atlantic with a surface ridge extending from a 1031 mb high in the northeast Atlantic near 36N45W through 32N60W then west to inland over the southeast CONUS. This surface ridge will persist through the week. The surface trough along 71W/72W will reach the northwest Bahamas by wednesday evening. The surface trough along 63W will continue westward reaching the Turks and Caicos by early Wednesday. For additional information please visit http://www.hurricanes.gov/marine $$ PAW