000 AXNT20 KNHC 120534 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 205 AM EDT TUE JUL 12 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...TROPICAL WAVES... Tropical wave in the central Tropical Atlantic extends along 46W/47W from 6N-18N moving west 15 to 20 kt over the past 24 hours. Wave coincides with a well-defined 700 mb trough depicted in the global models and precedes the leading edge of a surge of moisture as seen on the SSMI Total Precipitable Water imagery. No associated deep convection is noted. Tropical wave in the central Caribbean extends along 77W/78W from the south coast of Cube to over Panama moving west near 25 kt over the past 24 hours. Wave is trailing a 700 mb trough depicted in the global models and is embedded within a surge of moisture as seen on the SSMI Total Precipitable Water imagery. Scattered showers and isolated thunderstorms are from 14N-20N between 78W-84W. Tropical wave that was over Central America is no longer in the Caribbean basin. Please see the Pacific Tropical Weather Discussion under AWIPS/WMO headers MIATWDEP/AXPZ20 KNHC. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 14N17W and continues along 10N22W to 10N29W where the ITCZ begins and continues through a weak 1012 mb low near 10N40W to east of the tropical wave near 9N46W, then resumes west of the wave near 8N48W to the coast of South America near 6N54W. Clusters of isolated moderate convection are from 6N-9N between 13W-22W, from 3N-9N between 30W-40W, and from 7N-11N between 41W-47W. ...DISCUSSION... GULF OF MEXICO... An upper trough is centered near Brownsville, Texas covering the northwest Gulf while a second cutoff upper low dominates the northeast Gulf centered near 27N88W with upper level ridging between. Westerly flow aloft covers the south Gulf south of 23N. This is creating a diffluent environment across the central Gulf generating isolated showers and possible isolated thunderstorms north of 24N between 86W-91W. Scattered showers and isolated thunderstorms are from 22N-24N east of 86W to over Cuba and through the Straits of Florida. The diurnal surface trough extends at 12/0300 UTC from 21N91W to south Mexico near 18N93W generating scattered showers and thunderstorms south of 20N east of 93W to inland over the Yucatan peninsula. A surface ridge extends from the west Atlantic across north Florida and the north Gulf coast to the northeast Texas. The surface ridge will persist through Thursday. The diurnal surface trough will form each evening over the Yucatan and dissipate over the southwest Gulf late each morning. CARIBBEAN SEA... A cutoff upper low is in the central Caribbean near 15N76W and is enhancing the activity associated with the tropical wave. The monsoon trough extends from Colombia across Panama and Costa Rica south of the Caribbean but is generating scattered showers and isolated thunderstorms in the southwest Caribbean within 90 nm along the coast of Panama, Costa Rica and south Nicaragua south of 12N west of 81W and within 75 nm along the coast of Colombia between 8N-11N. Saharan dust and dry air are seen on the last visible satellite imagery, leaving the Caribbean east of 75W under clear skies tonight. 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, except near gale force winds along the northwest coast of Colombia during the overnight hours through early Thursday. The Caribbean tropical wave will move across the remainder of the basin through Tuesday night. ...HISPANIOLA... Skies have cleared across the island tonight. Afternoon showers and thunderstorms will be possible over the next few days. ATLANTIC OCEAN... An upper ridge is in the southwest Atlantic near 25N76W and is providing difflunce aloft to the west to generate scattered showers and isolated thunderstorms from 25N-28N between 76W-80W including the northern most Bahama islands. A weak surface trough is north of Puerto Rico generating scattered showers and isolated thunderstorms from 20N-23N between 64W-68W. Otherwise, a broad surface ridge dominates the Atlantic again tonight with a 1026 mb high in the northeast Atlantic near 33N30W with a ridge axis extending through 28N49W to a 1022 mb high in the west-central Atlantic near 27N65W continuing west-northwest across north Floria along the north Gulf of Mexico coast. This surface ridge will persist through the week with the surface 1022 mb high shifting westward. For additional information please visit http://www.hurricanes.gov/marine $$ PAW