000 AXNT20 KNHC 201808 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 208 PM EDT Tue Aug 20 2019 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 1745 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave has an axis along 23W from 20N southward, moving W around 15 kt. TPW imagery shows that the wave is accompanied by a large area of high moisture content. Scattered moderate convection is from 06N-13N between 22W-26W. An Atlantic Ocean tropical wave is along 43W from 20N southward, moving W at 10-15 kt. No significant convection is noted along the wave axis due to SAL intrusion. This is limiting showers on either side of the wave. A tropical wave along 50W from 10N-23N originated from the subtropics and continues to move westward at 15 kt. Isolated showers are possible near the vicinity of the wave axis. However, convection is currently limited due to dry air in the area. A western Caribbean tropical wave is along 84W from 21N southward, moving W around 15 kt. Scattered moderate to strong convection is seen within 180 nm of the wave axis from 15N-21W between 81W-87W with some additional showers and tstorms between Jamaica and the Windward Passage. Expect scattered to widespread showers and tstorms to continue over the NW Caribbean through today. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea-Bissau near 11N16W to 07N30W to 08N46W. The ITCZ extends from 08N46W to 06N56W. Aside from the convection mentioned with the tropical waves, scattered moderate convection is from 05N-10N between 27W-37W. GULF OF MEXICO... A 1021 mb surface high is in the Southeast Plains centered near 33N83W. Ridging extends across most of the Gulf with the exception of the SE Gulf. A surface trough extends across Florida from 28N80W to the Florida Keys near 23N82W. Scattered showers and tstorms are seen from 24N-25N between 81W-83W and in the northern Gulf from 28N-30N between 85W-90W with cloudy conditions. In the Bay of Campeche, a surface trough extends from 23N93W to 18N94W. Scattered moderate convection is present 180 nm west of the trough. Similar activity is seen over the Yucatan Channel. A surface ridge extending across the northern Gulf from Bermuda high pressure will maintain mainly gentle to moderate E to SE winds across much of the Gulf through Sat. The passage of a tropical wave and surface trough on Wed night will support fresh to locally strong winds in the SW Gulf Wed night and Thu. CARIBBEAN SEA... Convection over the NW Caribbean is associated with a tropical wave in the area. See section above for details. Scattered moderate to isolated strong convection is seen west of 77W to the Yucatan Peninsula. Scattered showers and isolated tstorms are seen across Colombia, Panama, Costa Rica and Nicaragua south of 12N. Drier air is over the E Caribbean E of 73W with little to no significant showers. The latest ASCAT pass shows moderate to fresh trades in the central Caribbean, with moderate trades over the remainder of the central and NW Caribbean. A tropical wave over the western Caribbean near 84W will exit the basin by tonight. Bermuda high pressure north of the area will maintain fresh to strong trade winds over the south-central Caribbean through tonight. Winds will remain fresh to locally strong in this region through Sat as the pressure gradient persists between high pressure north of the region and low pressure over Colombia. The next tropical wave will move across the Lesser Antilles on Wed night, then continue moving westward across the Caribbean through the rest of the week. ATLANTIC OCEAN... Broad upper-level troughing is over the W Atlantic. Scattered to numerous moderate convection is over the Bahamas from 21N-26N between 72W-78W. Scattered showers are present from 28N-31N between 56W-60W. High pressure dominates the remainder of the basin, anchored by a 1024 mb high near 31N52W. Scattered showers and thunderstorms will persist into tonight near the Bahamas and Great Bahama Bank as the remnants of a surface trough move across southern Florida. A surface ridge extending westward from Bermuda high pressure will dominate the northern waters through Sat, with gentle to moderate E to SE winds prevailing across much of the region. Fresh trades are expected at night between the Turks and Caicos Islands and Hispaniola. $$ MMTorres