Tropical Weather Discussion
— Atlantic
Office:
KNHC
Issued:
Jul 18, 2026 at 10:11 AM UTC
TWD
000 AXNT20 KNHC 181011 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Sat Jul 18 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURE... Caribbean Gale Warning: A tight pressure gradient between the western Atlantic high pressure ridge north of the basin along 27N-28N, and the Colombian low will continue to support NE to E winds pulsing to gale-force across the waters N of Colombia through early this morning and then again Sat night. Otherwise, strong to near- gale force trade winds and rough seas will prevail across the much of the central Caribbean into early Mon before contracting to south of 15N. Rough to very rough seas in the 12 to 14 ft range will develop during the times of peak winds. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave is along 29W, south of 18N, moving westward near 15 kt. A 1011 mb surface low is analyzed behind the wave near 14N27W. Scattered moderate convection is observed within 180 nm across the N semicircle of the surface low. A central Atlantic tropical wave is along 51W-52W, south of 17N, moving westward at 20 kt. Widely scattered moderate convection is noted from 07N to 10.5N between 48W and 55W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Mauritania near 21N16.5W and continues southwestward to a 1011 mb low pres near 14N27W to 08N43W. The ITCZ extends from 08N43W to 07.5N51W and then from 07.5N52W to 07.5N59W. Scattered moderate to isolated strong convection is present from 10N to 14N east of 22W and from 08.5N to 10.5W and between 54W to 62W. ...GULF OF AMERICA... Upper level low pressure across Florida and the far eastern Gulf during the past 36-48 hours extends into the lower atmosphere, and a weak surface trough is now across the Gulf along 83W-84W. The upper low and abundant low level moisture are resulting in scattered strong showers and thunderstorms over the NE Gulf waters, N of 25N and E of 87.5W. These storms can produce gusty winds, frequent lightning and suddenly higher seas. Mariners should exercise caution across this area. Local buoys show seas of 2 to 4 ft presently. Elsewhere, 1020 mb high pressure centered south of Louisiana dominates the basin, supporting moderate to fresh E to SE winds south of a line from the NE Yucatan to SE Texas. Elsewhere, light to gentle winds and slight seas prevail. For the forecast, low pressure across the eastern Gulf will remain nearly stationary through the weekend then begin to drift northward Sun night through early next week, supporting periods of active thunderstorms in that region. Elsewhere, weak high pressure will dominate, producing gentle to moderate winds and slight to moderate seas through the period. ...CARIBBEAN SEA... A Gale Warning remains in effect for the south-central Caribbean near the coast of Colombia. Please refer to the Special Features section for more details. Winds are expected to diminish below gale-force around sunrise this morning. The 1025 mb subtropical ridge centered near 28N55W in the central Atlantic extends westward to Florida, and is forcing strong to gale-force easterly trade winds across the central Caribbean, with the strongest winds occurring off Colombia and in the Gulf of Venezuela. Overnight satellite scatterometer data showed peak winds of 34 kt. Rough to very rough seas to 13 ft are found in these waters. Fresh to locally strong E winds and seas of 5 to 7 ft are present in the eastern Caribbean, and Windward Passage. Fresh winds are found across the Gulf of Honduras. Elsewhere, light to gentle winds and slight to moderate seas are prevalent. Isolated showers are found across the SE Caribbean waters, while scattered moderate convection extends between the Cayman Islands and the Windward Passage at this time. For the forecast, the pressure gradient between the Atlantic high pressure ridge and the Colombian low, will support NE winds pulsing to gale-force across the waters N of Colombia through near sunrise this morning and then again Sat night. Otherwise, strong to near- gale force trade winds and rough seas will prevail across the much of the central Caribbean into early Mon, before contracting to south of 15N through Tue. East winds will pulse fresh to locally strong each evening this weekend in the Windward Passage. ...ATLANTIC OCEAN... A weak surface trough in the north-central tropical Atlantic supports isolated showers north of 25N and between 39W and 47W. Meanwhile, a broad subtropical ridge centered over the central Atlantic extends westward along 27N-28N to Florida, and sustains moderate to fresh easterly winds and seas of 4-8 ft south of 25N and west of 35W, with highest winds and seas between 55W and the Lesser Antilles. In the far eastern Atlantic, fresh to locally strong N to NE winds and seas of 4-7 ft are noted north of the monsoon trough and east of 30W. Moderate to fresh SW winds and seas of 4-7 ft are evident south of the monsoon trough and east of 30W. Elsewhere, moderate or weaker winds and moderate seas prevail. For the forecast west of 55W, the western Atlantic subtropical ridge extends along 27N-28N, and will gradually weaken and drift northward this weekend, as a broad surface trough forms E of 50W. This trough will shift westward and reach along 65W by Wed. Moderate to fresh trades will prevail S of 24N through early Tue, with gentle winds to the N. Pulsing strong winds are expected during the evenings this weekend N of Hispaniola and in the Windward Passage. $$ Stripling