000 AXNT20 KNHC 140003 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 803 PM EDT SAT AUG 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 2345 UTC. ...TROPICAL WAVES... Tropical wave is in the E Atlantic from 10N-20N with axis near 31W, moving W at 10 kt within the last 24 hours. CIRA LPW imagery from the surface to 850 mb depict patches of dry air in the wave environment. Meteosat enhanced imagery show this is due to the presence of Saharan dry air and dust. The wave is also embedded in a neutral to unfavorable deep layer wind shear environment that hinder convection at the time. Tropical wave reaching the Caribbean extends from 05N-15N with axis near 55W, moving W at 20-25 kt within the last 24 hours. CIRA LPW imagery from the surface to 850 mb depict patches of dry air in the wave environment. However, no Saharan dry air or dust is observed affecting the wave at the time. Favorable deep layer wind shear and a region of upper level diffluence support scattered showers from 07N-14N between 51W and 59W. Tropical wave extends from 11N-21N with axis near 90W, moving W at 10 kt within the last 24 hours. The wave is in a region of favorable to neutral deep layer wind shear that supports scattered heavy showers and tstms over northern Central America and the Yucatan Peninsula. ...ITCZ/MONSOON TROUGH... The Monsoon Trough axis extends from the African coast near 14N17W to 08N30W to 08N41W. The Intertropical Convergence Zone axis extends from 08N41W to 09N51W. Aside from the convection associated with the tropical waves. Scattered heavy showers are from 06N-15N E of 21W. ...DISCUSSION... GULF OF MEXICO... North-northeasterly flow aloft continues across much of the Gulf this evening between an upper level anticyclone centered over E Texas, and an upper level low centered over south Florida. Mid to upper level energy continues to ride around the eastern flank of the anticyclone, and in combination with moist SE low-level flow is resulting in scattered heavy showers and isolated tstms over the northwest waters of the Gulf north of 25N W of 85W. Similar convection is within 60 nm off the Yucatan Peninsula associated with a tropical wave with axis near 90W. See tropical waves section for details. Otherwise...the remainder of the basin is under the influence of a ridge with axis extending from the Florida peninsula west-southwest to near 22N87W. Generally moderate to fresh anticyclonic winds prevail with slightly stronger south to southwest winds expected across the far NW waters through Sunday. The ridge axis will slowly lift northward through the weekend with moderate to fresh E-SE winds forecast early next week. CARIBBEAN SEA... Most of the active weather in the Caribbean basin remains confined to the NW Caribbean waters associated primarily with a middle-level low centered near 19N84W and a divergent environment in the upper levels. This active weather is in the form of scattered heavy showers and isolated tstms N of 15N W of 74W. Farther east...a well-defined surface trough with axis from 13N71W to 19N70W. This area of low pressure is supporting scattered heavy showers and tstms from 15N-20N between 65W and 72W, including western Puerto Rico and Dominican Republic. The trough is forecast to reach near 70W/71W by Sunday morning, then dissipate late Sunday or early Monday. Otherwise...trades will range from moderate to fresh breeze levels and gradually increase fresh to strong across the central waters through Monday generally between 67W-77W. ...HISPANIOLA... An upper level low is centered S of Haiti while a small anticyclone is centered NE of Dominican Republic generating diffluence aloft to support scattered heavy showers and tstms from 15N-20N between 65W and 72W, including the Dominican Republic and adjacent waters. A surface trough with axis near 71W supports this convection as well. Moisture guidance suggests that this activity will continue to hold as it passes to the south of the island, and along the southern portion of the island through Sunday evening. Gusty winds can be expected with this activity. ATLANTIC OCEAN... The upper level low centered in south Florida is pulling ample deep moisture northward from the western Caribbean Sea north to over much of the Bahama islands, and also waters between the Bahamas and south Florida. This is leading to scattered showers and thunderstorms to occur from central Cuba north to 29N W of 76W. Farther east...a weakness within the subtropical ridging is analyzed as three surface troughs with no convection. The remainder of the central and eastern Atlantic is under the influence of a surface ridge anchored by a 1028 mb high centered across the Azores near 39N27W providing ample subsidence and relatively dry and stable conditions across those portions of the Atlantic basin. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS