000 AXNT20 KNHC 132343 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 743 PM EDT WED JUL 13 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 1800 UTC surface analysis and satellite imagery through 2330 UTC. ...TROPICAL WAVES... A tropical wave came off the West African coast earlier this morning. Its axis extends from 20N19W to 06N21W and model guidance indicates it will move W near 20 kt within the next 24 hours. Global model streamlines at 700 mb show the wave is associated with a low centered near 12N20W and an inverted trough at 500 mb. Meteosat imagery shows Saharan dry air and dust in the wave's environment that along with strong deep-layer wind shear limits the convection to the southern portion of the wave mainly S of 10N between 16W-26W. A tropical wave is moving across the central Atlantic with axis from 15N46W to 05N48W, moving W at 10 kt within the last 24 hours. The wave coincides with a low amplitude 700 mb trough as depicted in global models guidance and is embedded within shallow moisture as indicated by CIRA Layer Precipitable Water imagery. No significant convection is related to this wave as this time as Saharan dust and dry air prevail in its environment. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across Africa into the east Tropical Atlantic near 20N17W and continues to 08N33W where the ITCZ begins and continues to the coast of South America near 09N61W. Aside from the convection associated with the tropical wave, isolated showers are within 100nm on either side of the ITCZ. ...DISCUSSION... GULF OF MEXICO... A surface ridge extends across the basin anchored by a 1022 mb high centered over the NE Gulf near 29N86W. With this, a gentle to moderate anticyclonic flow prevails. An upper-level low centered over the NE portion of the basin also is supporting scattered moderate convection N of 26N and E of 90W. Little change is expected during the next 24 hours. Fresh to strong winds will develop in the Bay of Campeche the next two days associated with a diurnal surface trough forming over the Yucatan Peninsula. CARIBBEAN SEA... Scattered showers are observed within 50 nm of the coasts Costa Rica and Panama associated with the EPAC Monsoon Trough. Fair weather prevails elsewhere due to strong subsidence and dry air. Expect for the next tropical wave to enter the E Caribbean by early Friday. ...HISPANIOLA... Isolated showers are observed across the SW portion of the island due to diurnal hearting and low level moisture. This activity will dissipate quickly this evening. Dry weather is expected during the next 24 hours due to strong subsidence and dry air. ATLANTIC OCEAN... Two tropical waves are moving across the basin. Please refer to the section above for details. Surface ridging continues to dominate the remainder of the basin anchored by a 1021 mb high centered near 29N76W and a 1027 mb high near 38N28W. A weakness in the ridge is being analyzed as a surface trough extending from 28N58W to 25N61W. Little change is expected through the next 24 hours. For additional information please visit http://www.hurricanes.gov/marine $$ ERA