000 AXNT20 KNHC 292238 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Jul 29 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...TROPICAL WAVES... An Atlantic tropical wave is near 30W from 05N to 18N southward and moving west around 10 to 15 kt. Scattered moderate convection is evident from 06N-09N between 25W-30W. This weak wave is mainly identifiable via 700 mb trough diagnostics. Another Atlantic tropical wave is near 52W from 18N southward and moving west around 20 kt. No significant convection is noted currently in association with the wave. However, the wave is apparent as a trough in the surface winds. A Caribbean tropical wave was reanlyzed to 76W from 13N southward through western Colombia, and moving west around 10 to 15 kt. No significant convection is observed near this tropical wave. ...MONSOON TROUGH/ITCZ... A monsoon trough extends across the coast of Senegal at 14N17W to 09N30W to 07N40W. At this time, there is no coherent ITCZ west of the monsoon trough. In addition to the convection associated with the tropical wave near 29W, scattered moderate convection exists from 07N-10N east of 25W. ...GULF OF MEXICO... A surface trough is noted over the northwestern Gulf of Mexico, near the southeast Texas Coast. Isolated showers and thunderstorms is east of this trough from 22N to 27N between 87W. Surface ridging extends westward from 1018 mb high pressure near 26N86W into northeast Mexico. Light to gentle breezes and slight seas are evident across the Gulf. For the forecast, the high pressure will drift westward and dominate the Gulf region during the upcoming weekend then reorganize over the E Gulf by early next week, with little change in winds and seas. ...CARIBBEAN SEA... Recent ship and buoy observations along with earlier scatterometer satellite data indicate mostly moderate to fresh trade winds across much of the eastern and central Caribbean, with 5 to 7 ft seas. Observations also indicate there is fresh to strong trade winds across A moderate north-south pressure gradient between ridging north of the Caribbean and lower pressure over N South America is contributing toward fresh to strong NE to E trades over the south-central Caribbean and just south of Hispaniola. Elsewhere, the trades are gentle to fresh. Seas are 6-8 ft in the central Caribbean, 4-6 ft in the E Caribbean, and 3-5 ft in the W Caribbean. Besides the convection associated with the tropical waves near 66W and 81W, no significant deep convection is observed. For the forecast, freshening tradewinds are expected across E and central portions of the Caribbean through tonight as the Atlantic ridge builds modestly across the W Atlantic. Fresh to strong trades will prevail across south central portions as well as the south central coast of Hispaniola through Sun night before the ridge begins to weaken. Strong winds to around 30 kt are expected at night near the coast of Colombia and in the Gulf of Venezuela Fri night through Mon night. ...ATLANTIC OCEAN... The Atlantic ridge extends west-southwest from the 1029 mb Azores High across central Atlantic to Florida. The ridge is sustaining light to gentle trades across all of the waters, except for fresh SE winds just north of Hispaniola. Seas are 6-7 ft south of 22N and 4-5 ft north of 22N. In addition to the convection mentioned in the Tropical Waves and Monsoon Trough/ITCZ sections, scattered moderate convection is noted north of 30N between 65W-75W in association with a sharp upper-level trough. For the forecast W of 65W, the Atlantic ridge centered on the Azores high will dominate the forecast waters through the period, while a surface trough will remain over or just off the coast of the SE United States. Expect fresh to locally strong easterly winds late afternoon through the night just off the N coast of Hispaniola, including approaches to the Windward Passage, most of the forecast period. Moderate to fresh S to SW winds are expected across the far NW waters Sun night through Mon night. $$ Christensen