000 AXNT20 KNHC 300542 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 142 AM EDT THU JUN 30 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 0515 UTC. ...SPECIAL FEATURES... A strengthened pressure gradient is expected to materialize across the Gulf of Venezuela by 01/0000 UTC and generate near gale to gale force NE winds. See latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...TROPICAL WAVES... Tropical wave extends from 06N26W to 15N27W moving W at 15 kt. The wave coincides with subtle 700 mb troughing between 25W-32W and remains embedded within Saharan dust north of the Monsoon Trough region. As a result...scattered moderate convection is confined within 120 nm either side of a line from 09N22W to 04N30W. Tropical wave extends from 07N53W to 17N53W moving W at 20 kt. The wave coincides with broad 700 mb troughing between 50W-60W. Isolated moderate convection is from 08N-11N between 48W-51W. Tropical wave extends from 04N67W to 15N68W moving W at 15 kt. The wave continues moving on the southern periphery of a SW North Atlc mid-level ridge anchored near 30N60W. Scattered moderate convection is across Venezuela from 02N-09N between 64W-69W. ...ITCZ/MONSOON TROUGH... The Monsoon Trough extends from the African coast near 12N16W to 06N25W to 05N33W. The Intertropical Convergence Zone axis extends from 05N33W to 08N43W to 07N58W. Scattered moderate convection is within 120 nm either side of the axis between 18W-38W...and from 09N-13N between 42W-48W. ...DISCUSSION... GULF OF MEXICO... Broad middle to upper level troughing is noted on water vapor imagery over much of the eastern CONUS with a broad base dipping to 30N. The west-southwesterly flow aloft and maximum diffluence south of the troughing is supporting weak surface troughing extending from southern Georgia to coastal Louisiana and along the Texas coastline to Corpus Christi this evening. Weakening mid- level energy noted over the NW Gulf waters also supports a surface trough extending from 25N93W to 29N92W. Given the favorable dynamics aloft and surface boundaries in place... widely scattered showers are occurring N of 27N E of 90W...and N of 25N W of 90W. Otherwise...a weak surface ridge axis extends across the southern Florida peninsula to the SW Gulf with generally gentle to occasional moderate anticyclonic winds expected through Thursday as ridge axis remains nearly stationary. The frontal troughing to the north will also remain stationary through the remainder of the week. CARIBBEAN SEA... An upper level ridging extends over the western Caribbean W of 78W. This feature is providing an diffluent environment aloft supporting widely scattered showers and tstms generally S of 19N between 81W-89W...including inland portions of Central America. The remainder of the basin remains under the influence of a very broad troughing aloft as an upper level low is centered over the Turks and Caicos Islands near 22N72W. The troughing supports isolated showers across Hispaniola this evening. In addition...a tropical wave along 68W is introducing isolated showers to the NE Caribbean S of 15N E of 70W. The wave is expected to move west and increase precipitation probabilities during the next few days for the south-central portion of the basin. Finally...while moderate to fresh trades prevail across much of the basin...fresh to strong trades persist S of 17N between 64W-80W due to a strengthened pressure gradient across the central Caribbean. Little change is expected during the next 24 to 36 hours. ...HISPANIOLA... Currently...isolated showers continue this evening. Southwesterly flow aloft is noted on water vapor imagery as an upper level low is centered north of the island near 22N72W. This environment along with peak daytime heating and instability will promote isolated showers and tstms again later today during the late afternoon and early evening hours. ATLANTIC OCEAN... Weak frontal troughing is analyzed across the SE CONUS and portions of the far NW Atlc discussion waters providing focus for isolated showers and tstms generally W of a line from 26N80W to 32N72W. Surface ridging is expected to build west during the next 12 to 24 hours. Otherwise...the remainder of the basin is dominated by a surface ridge anchored on a 1037 mb high centered NW of the Azores near 42N38W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN