Atlantic Tropical Weather Discussion
952 AXNT20 KNHC 192252 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Thu Aug 20 2026 Tropical Weather Discussion for North America, Central America Gulf of America, 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 2200 UTC. ...TROPICAL WAVES... A tropical wave is along 27W, south of 21N, moving westward at 10 to 15 kt. Scattered moderate isolated strong convection is observed from 07N to 12N and between 21W and 30W. A tropical wave is near 58W, south of 18N, moving westward at 10 to 15 kt. Convection is isolated along the ITCZ near the wave at this time. A tropical wave is moving across the central Caribbean along 73W, south of 19N, moving westward at 10 to 15 kt. Scattered moderate isolated strong convection extends northeastward across Hispaniola, the Mona Passage and into the Atlantic N of Puerto Rico, as the wave interacts with an upper level trough across this area. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 13N17W to 11N26W and to 10.5N48W. The ITCZ extends from 10.5N51W to NE Venezuela near 10N62W. Beyond convection described above with the tropical waves, scattered moderate isolated strong convection is noted from 06.5N to 13.5N between 30W and 43W. ...GULF OF AMERICA... A ridge dominates the Gulf region, anchored by 1019 mb high pressure located near 27N89.5W. This pattern supports a gentle to moderate anticyclonic wind flow across the basin with slight to moderate seas of generally 3 ft or less. An upper level low center across the Florida Peninsula and adjacent waters is supporting scattered showers and thunderstorms across large portions of the interior that are shifting eastward toward the Atlantic coast. Another large cluster of moderate to strong convection is across much of the Florida Panhandle and extends across the nearshore coastal waters between Apalachicola and Mobile Bay. For the forecast, relatively weak high pressure over the central Gulf will prevail over the basin through the forecast period. This weak pressure pattern will support mostly gentle to moderate winds and slight to locally moderate seas. A diurnally induced surface trough will generate fresh to locally strong winds north and west of the Yucatan Peninsula in the early evenings. These winds will shift westward away from the peninsula at night as the trough migrates into the SW Gulf. ...CARIBBEAN SEA... Recent satellite scatterometer data indicated fresh to strong winds across the south-central Caribbean, and moderate to fresh winds across the remainder of the central part of the basin. Seas are 5 to 8 ft with these winds. Gentle to moderate trades and slight to moderate seas prevail elsewhere. Scattered moderate isolated strong convection extends northeastward across Hispaniola, the Mona Passage and into the Atlantic N of Puerto Rico. Scattered showers and a few thunderstorms are occurring across the SW Caribbean and into coastal portions of southern Nicaragua, Costa Rica and western Panama. Shallow moisture, embedded in the trade wind flow ahead of an approaching tropical wave, is producing scattered showers across the Lesser Antilles and SE Caribbean S of 16N. For the forecast, the pressure gradient between a subtropical ridge north of the basin and relatively lower pressure in northern South America will generally support fresh to strong trades along with rough seas across the south-central Caribbean through much of the forecast period. Moderate to fresh trades and moderate seas will prevail over the north-central and eastern Caribbean through the weekend and into early next week, and increase in coverage over the tropical Atlantic and eastern Caribbean starting Sun night as a tropical wave moves across those waters. Elsewhere, moderate or lighter winds and slight to moderate seas are expected. ...ATLANTIC OCEAN... A stationary front extends from 1018 mb low pressure near 33N48.5W to 30N50W to a 1016 mb low pressure center located near 29N61W, then continues as a dissipating frontal trough to just east of the SE Bahamas near 24N73W. Middle level troughing overhead of the stationary front is supporting clusters of scattered moderate isolated strong showers and thunderstorms within 180 nm S of the front and low between 46W and 62W. Satellite scatterometer data shows moderate to fresh S to SW winds within about 150 nm south of the front between 46W and 64W. Seas area 4 to 5 ft within these winds. The remainder of the Atlantic is dominated by the Azores High centered near 38N30W, that extends southwestward across 30N and then a narrow ridge south of the front to near 70W. Under the influence of this system, mainly gentle to moderate trade winds are occurring S of 24N E of 40W, and S of 22N W of 40W. However, small areas of fresh winds are noted approaching the Lesser Antilles, while moderate to fresh NE winds prevail from 18N to 25N E of 30W. Seas across these areas are 6 to 7 ft. Otherwise, seas are generally moderate E of 70W, and slight to moderate W of 70W. Saharan Air continues to dominate the Tropical Atlantic N of 13N between Africa and the Lesser Antilles. For the forecast west of 55W, the stationary front will begin to weaken tonight through Thu, and drift northward as high pressure builds modestly westward into the Bahamas through Fri. Elsewhere, a weak pressure gradient will support mostly light to gentle winds over most of the waters north of 23N going into the upcoming weekend and into early next week. Moderate to locally fresh trades are expected south of about 22N, especially off the coast of Hispaniola throughout the period.