346 AXNT20 KNHC 260005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Wed Jul 25 2018 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 2345 UTC. ...TROPICAL WAVES... A tropical wave is over central Atlantic with axis along 35W extending from 04N-19N, moving westward at 15-20 kt. A large area of Saharan dry air and dust continue to hinder convective activity from developing at the time. A tropical wave is over the central Atlantic with axis along 47W from 04N-15N, moving westward at 15-20 kt. A large area of Saharan dry air and dust continue to hinder convective activity from developing at the time. A tropical wave is over the eastern Caribbean with axis along 64W from 08N-18N, moving westward at 15 kt. A large area of Saharan dry air and dust hinder convective development at the time. A tropical wave is over the western Caribbean with axis along 82W from western Panama to 19N, moving westward at 15-20 kt. Abundant moisture in the SW Caribbean associated with EPAC monsoon trough and diffluence aloft support scattered heavy showers and tstms S of 11N between 78W and 83W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Africa near 11N15W to 09N20W to 09N34W to 06N39W. The ITCZ extends from 06N39W to 07N46W...then resumes W of a tropical wave near 07N49W and continues to the coast of South America near 06N57W. Scattered showers are off the coast of Africa from 07N-11N E of 18W. ...DISCUSSION... GULF OF MEXICO... An upper level trough is over the NE Gulf of Mexico and N Florida. This feature supports a surface trough from 29N85W to 26N86W to 24N89W. Diffluence aloft east of the upper level trough is sustaining convection within 150 nm E of the trough. Convection is expected to continue over the SE Gulf through Thu. The Atlantic subtropical ridge will then extend an axis SW across the eastern Gulf. Surface ridging is forecast to continue through the weekend, thus providing light to gentle variable flow across the basin. Elsewhere, a surface trough will move off the Yucatan Peninsula into the Bay of Campeche each evening, accompanied by fresh nocturnal winds. Scattered to isolated showers are possible in the Bay of Campeche with the surface trough. CARIBBEAN SEA... Two tropical waves are over the Caribbean. See section above. Shallow moisture and diffluence aloft supports scattered heavy showers and tstms over Cuba. Similar convections is occurring over the eastern Dominican Republic. Relatively dry and stable conditions persist elsewhere. Expect the surface pressure gradient to support fresh to strong winds in the south- central basin through Fri. Elsewhere, stable conditions with light to moderate winds are expected. ATLANTIC OCEAN... Two more tropical waves are moving across the basin lacking convection due to the presence of the dry air in the Saharan Air Layer. Refer to the tropical waves section above for more details. Scattered moderate convection is across the W Atlantic including the northern Bahamas, W of 75W. Farther east, a middle to upper level low supports an area of scattered moderate convection from 22N-28N between 56W-64W. Otherwise, the Atlantic subtropical ridge dominates the remainder basin being anchored by a 1031 mb high centered near 37N55W. Expect convection north of the Bahamas through the weekend. Thesurface pressure gradient between the Atlantic 1031 mb subtropical high and the low pressure over the southeast U.S. will produce moderate to fresh southerly winds across the waters north of 25N and west of 70W including Florida coastal waters today. Moderate to fresh winds are also expected south of 22N, including approaches to the Windward Passage. Surface ridging will dominate the central and eastern Atlantic through the end of the week providing stable and dry conditions. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa/Ramos