000 AXNT20 KNHC 281742 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 PM EDT THU JUL 28 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 far east Tropical Atlantic extends along 19W/20W from 8N-17N with a 1011 mb low along the wave near 10N20W. Wave and low are moving west 10 to 15 kt over the past 24 hours. Wave coincides with a 700 mb trough as depicted in the global models and is embedded within broad area of moisture as seen on the SSMI Total Precipitable Water imagery. Clusters of scattered moderate to isolated strong convection are from 9N-13N between 20W-23W. Tropical wave in the east Tropical Atlantic west of the Capo Verde Islands extends along 34W from 10N-17N moving west near 15 kt over the past 24 hours. Wave coincides with a 700 mb trough south of 16N as depicted in the global models and is embedded within a high amplitude surge of moisture as seen on the SSMI Total Precipitable Water imagery. Scattered moderate convection is within a 60 nm radius of 14N36W. Tropical wave in the west Tropical Atlantic extends along 47W/48W from 10N-16N moving west 10 to 15 kt over the past 24 hours. Wave coincides with a weak 700 mb trough south of 16N as depicted in the global models and is embedded within a weak surge of moisture north of 12N as seen on the SSMI Total Precipitable Water imagery. No associated deep convection or shower activity. Tropical wave in the west Caribbean extends along 82W/83W from 12N-22N moving west near 20 kt over the past 24 hours. Wave coincides with a well defined 700 mb trough as depicted in the global models and is embedded within a surge of moisture north of 16N as seen on the SSMI Total Precipitable Water imagery. No associated deep convection. Scattered showers and isolated thunderstorms are from 15N-21N between 80W-85W. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 19N16W and continues along 15N18W 13N24W 11N36W to 9N47W where the ITCZ begins and continues along 8N51W to South America near 8N60W. Clusters of isolated moderate convection are from 7N-13N between 27W-38W. ...DISCUSSION... GULF OF MEXICO... An inverted upper trough dominates most of the Gulf of Mexico this afternoon extending from south Mexico near 18N93W to over the north Gulf coast near Vermilion Bay, Louisiana. A pair of surface troughs are in the Gulf. One extends from 28N87W to 24N89W with scattered showers and isolated thunderstorms from 24N-28N between 86W-92W. A second surface trough is over the southwest Gulf from 23N92W to over Mexico near 18N94W with scattered showers and isolated thunderstorms south of 25N west of 95W to inland over Mexico. An upper ridge anchored in the west Atlantic extends over the east Gulf east of 87W. A surface ridge extends from the west Atlantic across central Florida to a 1018 mb high near 29N86W continuing to the Louisiana/Texas border. The surface ridge will persist through the weekend. A thermal trough will move off the west coast of the Yucatan peninsula each evening through the weekend. CARIBBEAN SEA... An upper ridge is anchored along the coast of Nicaragua near 13N83W covering the Caribbean west of 77W. The activity associated with the tropical wave is being enhanced by this upper ridge. An upper trough over the southwest Atlantic extends south over the east Caribbean east of 77W. The upper trough is embedded within dry stable air and strong subsidence, therefore is not producing any convection or shower activity. This is leaving the remainder of the Caribbean under mostly clear skies this afternoon. 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 central Caribbean through early Saturday. Winds will decrease slightly on Saturday and Sunday as the surface ridge over the west Atlantic weakens. The tropical wave will move over Central America tonight and Saturday. The next tropical wave will enter the east Caribbean Saturday. ...HISPANIOLA... Isolated showers and thunderstorms are developing across the Dominican Republic this afternoon leaving Haiti under clear skies. The upper low over the southwest Atlantic will shift westward to over the island Friday then northwest of the island on Saturday. Isolated afternoon/evening showers and thunderstorms will be possible through Saturday. Moisture will increase late in the weekend. ATLANTIC OCEAN... An upper ridge anchored near 31N62W dominates the west Atlantic and extends south over the Cuba. An upper low over the southwest Atlantic near 22N62W extends an upper trough southwest over the east Caribbean. The upper ridge to the northwest of the upper low is providing difflunce aloft to generate scattered to numerous showers and isolated thunderstorms from 23N-29N between 65W-73W. A surface ridge extends from a 1020 mb high near 27N75W across Florida into the Gulf of Mexico. Remnant moisture is generating isolated showers and possible thunderstorms from 27N- 31N between 58W-60W. A surface ridge dominates the east Atlantic anchored by a 1032 mb high north of the Azores. West Atlantic surface ridge will persist through Saturday when it begin to weaken through Sunday. For additional information please visit http://www.hurricanes.gov/marine $$ PAW