000 AXNT20 KNHC 301113 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Fri Jul 30 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 0600 UTC surface analysis and satellite imagery through 1100 UTC. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 32W/33W from 03N to 15N, moving westward at 10-15 kt. Scattered moderate convection is within 120 nm either side of the wave from 06N to 08N. A central Atlantic tropical wave has its axis extending from 20N59W to 13N57W and to inland Guyana. It is moving westward around 20 kt. Scattered showers moving quickly westward trail the wave from 10N to 12N between 49W and 56W. A western Caribbean Sea tropical wave has its axis along 81W south of 21N. It is moving westward near 16 kt. Scattered moderate convection exists near the northern part of the wave from 18N to 21N between 79W-81W. Scattered showers and isolated thunderstorms are within 120 nm east of the wave from 17N to 18N and within 60 nm west of the wave from 16N to 20N. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends off the coast of Senegal near 14N17W to 09N30W and to 06N42W. At this time, there is no coherent ITCZ west of the monsoon trough. Scattered moderate convection is within 240 nm south of the trough between 19W-25W and within 120 nm south of the trough between 27W-38W. ...GULF OF MEXICO... High pressure ridging extends across the Gulf of Mexico, anchored by a 1017 mb high near 27N89W. A trough is over the western Gulf waters along a position from 28N95W to 24N96W and to 20N95W. Another trough is over the far NE Gulf from 30N85W to 27N83W. Clusters of scattered moderate to isolated strong convection are over the SW Gulf southwest of a line from 21N97W to 18N93W. An area of increasing scattered moderate convection is over the northeastern Gulf from 28N to 30N between 85W and 88W. Partial overnight ASCAT data passes along with recent buoy observations reveal light to gentle winds across the basin. Seas throughout are in the range of 2-3 ft, with the exception of higher seas, in the 3-5 ft range, over the SW Gulf and eastern Bay of Campeche. For the forecast, the trough across the western Gulf will drift west and gradually dissipate through this afternoon. Atlantic high pressure extends westward across the basin, with a weak 1017 mb high centered near 26N89W. The high will drift westward and dominate the Gulf region during the upcoming weekend, then re-establish itself over the eastern Gulf by early next week. ...CARIBBEAN SEA... Numerous moderate to strong convection continues over far SW part of the basin south of 12N between 75W-80W, including to just inland the coast of Colombia. This activity is being sustained by instability created by the eastern segment of the Pacific monsoon trough that reaches to that part of the Caribbean Sea. Additionally, low-level speed convergence found there is also contributing to the longevity of this convection. Scattered showers and thunderstorms are confined to the waters from 16N to 20N west of 82W, including the Gulf of Honduras. This activity has increased during the past few hours. Upper-level divergence east of a small upper-level low noted on water vapor to be just east of Cozumel, Mexico is helping to keep this convection active. Overnight ASCAT data passes depict fresh to strong winds north of Colombia and moderate to fresh winds across the central and eastern Caribbean. Gentle to moderate winds are noted across the western Caribbean. Seas are in the range of 6-8 ft in the central Caribbean and around 3-5 ft elsewhere. For the forecast, fresh to strong trades over the central Caribbean will continue through early Mon, then diminish to fresh speeds through Tue night as Atlantic high pressure weakens. ...ATLANTIC OCEAN... Atlantic high pressure ridging extends west-southwest from a 1026 mb high near 30N52W to South Florida. Overnight ASCAT data helped with the location of the ridge. An elongated northeast to southwest oriented upper-level low is identified on water vapor imagery at 25N70W. Scattered showers and isolated thunderstorms are south of 22N to just inland the Dominican Republic between 68W-70W. Isolated showers and thunderstorms are observed elsewhere over the southwestern north Atlantic along with light to gentle winds near the ridge axis and moderate to fresh winds south of 24N. Seas are in the 3-5 ft. In the central Atlantic, a trough extends from near 22N42W to 30N45W with no significant convection noted. Otherwise, the aforementioned high pressure ridge also extends across this area. Light to gentle winds are near the ridge axis here as well, while moderate to fresh east winds are south of 24N. Seas are in the 3-6 ft range as detected by a couple of recent altimeter data passes. The high pressure dominates the eastern Atlantic. Moderate to fresh north to northeast winds are noted especially off the coast of Morocco, with seas of 4-6 ft. Atmospheric conditions are very dry and stable over the eastern Atlantic. It is also where Saharan dust is quite prevalent per latest GOES-16 GeoColor images. The dust also reaches westward to the central tropical Atlantic waters south of about 25N. For the forecast west of 65W, high pressure ridging near 27N will change little into early next week. Expect fresh to locally strong east winds during the late afternoons and at night just off the northern coast of Hispaniola, including approaches to the Windward Passage through early next week. Moderate to fresh south to southwest winds are expected across the far northwest waters Sun night through Mon night. $$ Aguirre