107 AXNT20 KNHC 261717 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 117 PM EDT Thu Jul 26 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 1200 UTC surface analysis and satellite imagery through 1600 UTC. ...TROPICAL WAVES... A tropical wave is near the Cabo Verde Islands with an axis extending from 18N22W to 05N23W, moving westward at 10 to 15 kt. This wave is well defined with a notable 700 mb trough in model guidance. Deep moisture interacting with the wave S of 10N is supporting scattered moderate convection from 07N to 10N between 21W and 26W. The remainder of the wave environment lacks convection due in part to the presence of Saharan dry air and dust. A tropical wave is over central Atlantic with an axis extending from 20N37W to 05N38W, moving westward at 10 to 15 kt. This wave is associated with a well defined trough at 700 mb. A large area of Saharan dry air and dust continue to hinder convection from developing around this wave. A tropical wave is over the central Atlantic with an axis extending from 11N52W to 06N52W, moving westward at 10 to 15 kt. Scattered thunderstorms are S of 13N within 90 nm of the wave axis. Strong deep layer wind shear and Saharan dry air and dust are hindering deep convection across the northern portion of the wave. A tropical wave over the central Caribbean has been re-analyzed as of 1500 UTC along 71W based off both long term satellite imagery and 700 mb model field data. Precipitable water satellite imagery shows a very dry environment across the central Caribbean, which along with strong deep layer wind shear are hindering convection S of Hispaniola. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from the coast of Africa near 12N16W to 07N33W. The ITCZ extends from 07N39W to 09N51W...then resumes W of a tropical wave near 09N54W and continues to 10N60W. Aside from convection associated with the tropical waves, scattered moderate convection is from 06N to 11N E of 20W, and within 180 nm N of the ITCZ axis between 54W and 60W. ...DISCUSSION... GULF OF MEXICO... An upper level trough prevails across the E Gulf with its base extending SW from central Florida to the Bay of Campeche. This trough supports a weakening stationary front that extends across the Florida Panhandle to SE Louisiana. It also supports a surface trough that extends from the Florida Big Bend SW to 26N89W. Numerous showers and tstms are within 120 nm SE of this trough. The front is transitioning to a surface trough. Both troughs are expected to lift north through tonight. Otherwise, the Atlantic subtropical ridge covers the remainder of the SE Gulf and will continue to build northwestward across the remainder of the basin through the weekend. Light to gentle variable flow will dominate the basin during this time period. CARIBBEAN SEA... A weak upper level low centered near Jamaica along with shallow moisture in the NW Caribbean support scattered showers and tstms N of 17N between 75W and 83W. In the SW basin, the monsoon trough supports numerous showers and tstms S of 11N. A tropical wave is crossing the central Caribbean waters. Please refer to the tropical waves section above for further details. GOES-16 water vapor imagery continues to indicate very dry conditions across the remainder of the basin while enhanced RGB satellite imagery indicates a thin layer of Saharan Air Dust moving across the area. Strong deep layer wind shear is also noted in the E Caribbean. These hostile factors are suppressing convection across the remainder of the Caribbean basin. A new tropical wave is forecast to move across the Lesser Antilles Friday night, with showers and thunderstorms beginning to spread across the southern Leeward islands starting this evening in advance of the wave. ATLANTIC OCEAN... Three tropical waves are moving across the basin. Please refer to the tropical waves section above for more details. Scattered showers and tstms N of 23N W of 75W are being supported by an upper trough along the eastern United States that extends across the Florida peninsula. This upper trough will prevail through Friday, enhancing shower and thunderstorm activity over this area. Farther east, an upper level low supports a surface trough that extends from 31N63W to 28N66W. These features support a broad area of cloudiness with scattered showers and isolated tstms from 20N to 31N between 62W and 70W. The Atlantic subtropical ridge dominates the remainder of the basin being anchored by a 1030 mb high centered near 37N54W. 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 $$ Latto