000 AXNT20 KNHC 121113 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 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 0600 UTC surface analysis and satellite imagery through 1045 UTC. ...TROPICAL WAVES... Tropical wave in the Tropical Atlantic extends along 41W/42W from 6N-18N with a weak 1013 mb low along the wave near 10N, all moving west near 15 kt over the past 24 hours. Wave was relocated based on a 700 mb trough south of 15N as depicted in the global models and is along 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 Caribbean extends along 81W from 20N to over Panama moving west near 30 kt over the past 24 hours. Wave is embedded within 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 within 120 nm of a line from 21N82W to Honduras near 16N86W and from 11N-14N west of the wave to inland over Nicaragua. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 19N16W and continues along 11N22W to 10N28W where the ITCZ begins and continues along 11N35W to east of the tropical wave near 11N40W, then resumes west of the wave near 9N45W to the coast of South America near 7N58W. Clusters of isolated moderate convection are from 7N-10N east of 18W to the coast of Africa, from 2N-10N between 32W-41W, and from 8N-10N between 44W-47W. ...DISCUSSION... GULF OF MEXICO... An upper low is centered over northeast Mexico near 24N98W covering the northwest Gulf while a second cutoff upper low dominates the northeast Gulf centered near 28N87W 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 thunderstorms from 23N-26N between 81W-94W. Isolated showers are possible north of 26N to the north Gulf coast between 87W-91W. The diurnal surface trough extends from 22N91W to south Mexico near 18N92W generating scattered showers and isolated thunderstorms from 19N-22N between 91W-94W. A surface ridge extends from the west Atlantic across north Florida and long the north Gulf coast to the northeast Texas. The surface ridge will weaken slightly through Thursday. The diurnal surface trough will form each evening over the Yucatan and dissipate over the southwest Gulf late each morning. CARIBBEAN SEA... The cutoff upper low has been absorbed by a broad upper trough that extends from the central Atlantic across Puerto Rico to over the central Caribbean near 13N80W and is enhancing the activity associated with the tropical wave. The monsoon trough extends from Colombia along 10N across Costa Rica generating scattered showers and isolated thunderstorms south of 11N between Colombia and west Panama. Saharan dust and dry air are seen on the last visible satellite imagery, leaving the Caribbean east of 80W under clear skies this morning. 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 remain clear across the island this morning. Afternoon showers and thunderstorms will be possible over the next few days. ATLANTIC OCEAN... An upper ridge is in the southwest Atlantic near 25N77W and is providing difflunce aloft to the west to generate scattered showers and isolated thunderstorms from 25N-27N west of 77W to the Florida coast and includes the northern most Bahama islands. A weak surface trough is north of Puerto Rico from 23N65W to 20N68W generating scattered showers and isolated thunderstorms from 19N-21N between 66W-68W. Otherwise, a broad surface ridge dominates the Atlantic this morning with a 1025 mb high in the northeast Atlantic near 33N30W and a ridge axis extending through 29N42W 26N55W to a 1021 mb high in the west-central Atlantic near 28N66W 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