000 AXNT20 KNHC 290553 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 153 AM EDT FRI JUL 29 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...TROPICAL WAVES... A tropical wave is in the far east Tropical Atlantic with axis that extends from 19N20.5W to a 1010 mb low near 11N21W. These features are moving west at about 10 kt over the past 24 hours. The wave coincides well with a low to mid level trough extending northward through the Cabo Verde Islands. Scattered moderate to isolated strong convection is evident within 90 nm of the center. Despite increased convection, the earlier microwave imagery showed the low level structure is still fairly weak at this time. A tropical wave is moving over the central Tropical Atlantic with axis from 19N41W to 10N41W, moving west at 15 to 20 kt over the past 24 hours. The tropical wave appears to have a high amplitude in the lower to mid levels of the atmosphere based on GOES high density winds with copious deep layer moisture in SSMI Total Precipitation Water Vapor Imagery. Recent scatterometer data also indicates associated surface troughing with an area of fresh trades on the northern portion of the surface trough from 19N to 15N between 40W and 45W. Scattered moderate convection is also noted with this tropical wave along the axis from 15N to 13N between 40W and 43W. A tropical wave is over western Tropical Atlantic from 17N54W to 09N53W, moving west 10 to 15 kt over the past 24 hours. This is a fairly weak and low amplitude tropical wave with very limited moisture. It is entering an area with fairly dry mid to upper levels and westerly shear. If the tropical wave persists through this area it will have little influence on the sensible weather for the next several days as it tracks west. A tropical wave is moving through the Gulf of Honduras, reaching from the western tip of Cuba through central Honduras near 16N85W. Scattered moderate convection is noted across the northwest Caribbean west of 85W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends across North Africa into the east Tropical Atlantic near 20N16W to 1010 mb low near 11N21W to 10N45W. The ITCZ begins from that point and continues to 08N55W. Aside from the convection related to the tropical waves and surface lows, scattered moderate convection is noted within 120 nm north of the monsoon trough between 45W and 50W. ...DISCUSSION... GULF OF MEXICO... Divergence aloft on the east side of an upper level low pressure area centered over the southwest Gulf of Mexico is enhancing the regular evening trough that emerges off the northwest coast of the Yucatan peninsula. Scattered moderate to isolated strong convection was noted in the Bay of Campeche earlier this evening, but this has since diminished. The surface trough reaches from 23N90W to 19N92W, with an accompanying trough located farther north over the north central Gulf from 27N88W to 24N90W. Surface ridging prevails from the western Atlantic across Florida into the eastern Gulf. Generally gentle to light flow prevails, except for locally moderate to fresh winds near the base of the trough in the Bay of Campeche. Scattered moderate convection will persist today as the upper low pressure track westwards through the next 24 hours, ahead of the northern portion of a tropical wave moving through Yucatan today. The tropical wave enhance the usually evening trough off western Yucatan tonight and tomorrow night. Otherwise little change is expected. CARIBBEAN SEA... An upper trough extends from 25N60W through the Mona Passage to the central Caribbean. This is supporting a lower to mid level trough moving across the Leeward and Windward Islands currently. An associated surface trough was resolved in recent Rapidscat data moving into Barbados. Little weather is associated with this deep layer trough however other than a few showers and brief increases in winds to 20 kt. The lower to mid level trough is expected to dampen out as it moves west-northwest through the next 24 to 48 hours. with little to no presence a surface trough. Otherwise, fresh to strong trade winds persist over the central Caribbean between the tropical wave exiting to the west and approaching deep layer trough. ...HISPANIOLA... The upper trough will likely support scattered moderate to isolated strong convection over interior areas of Hispaniola this afternoon and evening. ATLANTIC OCEAN... Three tropical waves are moving across the Tropical Atlantic. Please refer to the section above for details. A 1019 mb surface high is centered across the west Atlantic near 27N75W. To the east, another surface ridge prevails extending across the remainder of the basin anchored by a 1031 mb high near 41N32W. Little change is expected through the next 24 hours. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen