000 AXNT20 KNHC 071732 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 132 PM EDT SUN AUG 7 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 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...TROPICAL WAVES... Tropical wave is in the E Atlantic from 11N-20N with axis near 26W, moving W at 5 kt within the last 24 hours. Satellite derived data indicate the wave is in a favorable to neutral deep layer wind shear region. However, Saharan dry air and dust cover most of the wave environment, thus in part hindering convection at the time. Tropical wave is in the central Atlantic from 09N-15N with axis near 44W, moving W at 20 kt within the last 24 hours. Satellite derived data indicate the wave is in a favorable to neutral deep layer wind shear region. However, Saharan dry air and dust cover most of the wave environment, thus in part hindering convection at the time. Tropical wave is in the central Caribbean from 12N-20N with axis near 75W, moving W at 20 kt within the last 24 hours. Satellite derived data indicate the wave is in a neutral deep layer wind shear region while water vapor imagery show strong dry air subsidence in the same area. Shallow moisture is supporting isolated showers and tstms in the Windward passage, just ahead of the wave axis. Tropical wave is in a western Caribbean from 12N-22N with axis near 83W, moving W at 25 kt within the last 24 hours. Satellite derived data indicate the wave is in a neutral deep layer wind shear region and within an area of northerly flow aloft. Shallow moisture is in the wave environment, however it is devoid of convection at the time. ...ITCZ/MONSOON TROUGH... The monsoon trough extends across Africa into the east Tropical Atlantic near 12N17W and continues west to 11N31W. The ITCZ begins near 11N31W and then extends along 09N40W to 08N50W to the coast of Guyana near 06N57W. Besides any convection associated with the tropical waves discussed above, a cluster of heavy showers and isolated tstms is from 06N-11N between 50W and 58W. ...DISCUSSION... GULF OF MEXICO... Weak surface ridging continues to extend from the Atlantic across central and southern Florida to the SE Gulf of Mexico. A 1012 mb center of low pressure is in northern Florida from which a surface trough extends SW to 26N84W to 25N87W. This area of low pressure along with middle to upper level diffluence support heavy showers and scattered tstms from 27N-29N E of 91W. A surface trough remains in the SW Gulf waters extending from 24N90W to 18N93W supporting isolated showers within 60 nm either side of its axis. Except for N of 27N where NE-E gentle winds dominate, the remainder basin is under gentle to occasionally moderate S-SE flow. Little change is expected across the basin during the next two days. CARIBBEAN SEA... The main features across the Caribbean are two tropical waves, one in the western basin and the other over the central waters. However, no convection is associated with it. See the tropical waves section for further details. An upper level low over the Bahamas provides northerly flow across the western Caribbean while a broad middle to upper level ridge over central Atlantic waters provide easterlies becoming southeasterlies S of Hispaniola. Weak surface ridging extends from the Atlantic to the northern and eastern basin, which along with dry air subsidence from aloft support fair weather. The gradient between high pressure to the N-NE and lower pressure in the SW basin support fresh winds S of 15N between 66W and 71W. This zone of winds will amplify northward and westward within the next 24 hours as the center of high pressure in the Atlantic strengthens and drift west. The tropical waves will move out of the Caribbean by Monday night while a new wave moves across the Lesser Antilles. Otherwise, the EPAC monsoon trough support scattered showers S of 10N. ...HISPANIOLA... Cloudiness and possible isolated showers associated with a surface trough cover the central region of Dominican Republic. The surface trough is rapidly moving W-NW across the SW N Atlantic waters. However, shallow moisture associated with it and a diffluent middle to upper level environment may support showers later this afternoon through early Monday morning. Fair weather is expected the rest of Monday through Tuesday afternoon. ATLANTIC OCEAN... A surface trough is in the SW N Atlantic extending along 25N66W to the Dominican Republic near 19N70W. The trough is below an area of diffluence generated by an upper low over the western Bahamas and a broad ridge centered NE of Puerto Rico near 22N61W. Scattered heavy showers and tstms are from 21N-26N between 64W and 72W. A 1020 mb center of high pressure is NE of the trough near 26N59W, which is forecast to move farther W-NW within the next 24 hours. A middle to upper level low N of the area between 40W and 50W supports a cold front that extends from a 1016 mb low near 30N24W to 27N46W to 29N49W. A reinforcing cold front extends from 30N52W to 30N56W. Scattered to isolated showers associated with these fronts are N of 25N between 39W and 54W. The remainder of the Atlantic is dominated by surface ridging. The front in the north- central Atlantic will stall tonight while weakening through Monday night when its remnants will leave a surface trough with possible showers. The surface trough E of Turks and Caicos will continue to move W-NW along the western periphery of the surface ridge, thus supporting showers for the Bahamas the next two days. For additional information please visit http://www.hurricanes.gov/marine $$ RAMOS