000 AXNT20 KNHC 041811 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Aug 4 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 1200 UTC surface analysis and satellite imagery through 1630 UTC. ...TROPICAL WAVES... An Atlantic tropical wave is along 28W from 22N southward and moving W at 15 to 20 kt. Scattered moderate convection is seen from 09N to 17N between 22W and 30W. Another Atlantic tropical wave is near 42W from 18N southward and moving W near 20 kt. Scattered showers are present from 06N to 12N between 40W and 45W. A third Atlantic tropical wave is along 55W from 17N southward into N Suriname, and moving W near 15 kt. Scattered showers and isolated thunderstorms are occurring from 07N to 11N between 49W and 55W. A Caribbean tropical wave is near 76W from 15N southward to near the Panama-Colombia border, and moving W at 15 to 20 kt. Interacting with an upper-level low near Jamaica at 17N76W, scattered showers and a few thunderstorms are noted over the central and S central basin. The tropical wave previously located over the Bay of Campeche and S Mexico has moved farther W, and will mentioned in the Pacific Tropical Weather Discussion. ...MONSOON TROUGH/ITCZ... A monsoon trough extends from the Mauritania coast near 18N16W through a low pressure system near 13N27W to 09N53W. Scattered moderate convection is flaring up S of the trough along the African coast from Senegal southward to Sierra Leone. Similar conditions are also seen within 200 nm along neither side of the monsoon trough between 31W and 40W, and N of the trough from 08N to 11N between 45W and 49W. ...GULF OF MEXICO... A cold front stretches westward from the Florida Panhandle, passing just S of New Orleans to SE Texas. Scattered showers and thunderstorms are evident across the N Gulf. Moderate to locally fresh winds and seas up to 6 ft are near these thunderstorms. A surface ridge extends west-southwestward from S Florida across the central Gulf to central Mexico. Convergent SE winds near the ridge axis are coupling with divergent winds aloft to trigger scattered showers and thunderstorms over the E central Gulf and W Florida coast. An upper-level low near the E Mexican coast at 28N98W is creating scattered showers and isolated thunderstorms across the W edge of the Gulf. The surface ridge continues to sustain gentle to moderate winds and seas of 2 to 4 ft across the central and S Gulf. For the forecast, the frontal boundary will remain along the northern Gulf Coast through Fri. Scattered showers and thunderstorms will continue over the northern Gulf of Mexico this week along and south of the front. Similar activity exists north of 27N and east of 89W and will continue through today. Gentle to moderate westerly winds will prevail south of the front in the northeastern and north-central Gulf today. Moderate to fresh E winds will pulse off the NW Yucatan Peninsula into the Bay of Campeche every night through Sun night in association with a diurnal trough. Elsewhere south of the front, a surface ridge will dominate the Gulf waters over the next several days producing gentle to moderate anticyclonic winds. ...CARIBBEAN SEA... Enhanced by divergent winds associated with an upper-level low near Jamaica at 17N76W, convergent trade winds are producing scattered showers and isolated thunderstorms near the N tip of Colombia and adjacent waters. Refer to the Tropical Waves section above for additional convection across the basin. The pressure gradient in the S central Caribbean Basin has weakened nevertheless, latest satellite scatterometer and altimetery data indicate moderate to fresh trades and seas of 4 to 6 ft in this area. Elsewhere in the basin, gentle to moderate trades and seas at 2 to 4 ft are evident. For the forecast, the Bermuda high combined with lower pressures over northern Colombia will support pulsing fresh to locally strong winds over the south-central Caribbean through the end of the week. Expect fresh east to southeast winds in the Gulf of Honduras on Friday evening. Gentle to moderate trades will prevail elsewhere. ...ATLANTIC OCEAN... Convergent S to SW winds to the S of a cold front off the Georgia-S Carolina coast are creating scattered showers and isolated thunderstorms N of 27N between 76W and the E Florida coast. Convergent trade winds are triggering similar conditions near and N of Puerto Rico, and also near and NE of the SE Bahamas. An upper-level low SW of the Canary Islands near 26N24W is inducing scattered moderate convection from 22N to 26N between 18W and 24W. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections above for additional convection across the Atlantic Basin. The subtropical ridge related to the Bermuda-Azores high persists over the N central and W Atlantic Basin. Gentle to moderate trades and seas at 4 to 6 ft prevail N of 13N between the African Coast and 60W. Moderate to locally fresh SE to S winds and seas of 4 to 6 ft are seen N of 20N between 60W and the Florida-Georgia coast. Gentle to moderate with locally fresh SE to SW winds and seas at 4 to 7 ft are found across the rest of the basin. For the forecast W of 65W, fresh to strong south to southwest winds and scattered showers and thunderstorms will continue offshore NE Florida today to the south of the cold front, which will become a stationary front and linger along the U.S. East Coast for the rest of the week. Fresh winds will pulse north of Hispaniola, including the approaches to the Windward Passage, Thu night and Fri night. Otherwise, a surface ridge associated with the Bermuda-Azores high will persist for the next several days. $$ Chan