Atlantic Tropical Weather Discussion
658 AXNT20 KNHC 151712 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Sat Aug 15 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: The pressure gradient remains tighten between surface ridging over the W Atlantic and the Colombian Low. This will again favor increasing winds in the south-central Caribbean, supporting gale-force NE to E winds off Colombia this evening and early Sunday morning. Expect rough to very rough seas to near 15 ft near and downwind of these winds. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NWS Offshore Zone Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAOFFNT3.shtml for further details. Heavy Precipitation in South Central America and Colombia: Two tropical waves will propagate into Central America over the next several days, and will interact with enhanced divergence aloft and an active monsoon trough. The first tropical wave is located over the western Caribbean and over Panama. As this wave continues westward, expect heavy precipitation to continue in Costa Rica, the Darien region and into Choc-Colombia on Saturday and into Sunday. By Sunday, the second tropical wave enters the west Caribbean. Long fetch westerly flow is expected to occur from Sunday into Monday, favoring an increase in available moisture into Colombia. The heaviest precipitation is expected in Costa Rica throughout the day on Saturday and into early Sunday morning, while the heaviest precipitation in Panama, the Darien Region, and Choc- Colombia occurs Sunday into Monday. There is some uncertainty on how far south the heaviest rainfall could reach, particularly due to how far south the available moisture and the westerly flow enters the region. Please refer to the WPC International Desk and local weather services for more information. ...TROPICAL WAVES... A tropical wave extends from 05N to 20N with axis near 27W, moving westward at 15-20 kt. Scattered moderate convection is from 06N to 14N between 22W and 32W. A tropical wave extends from 04N to 20N with axis near 41W, moving west at around 15-20 kt. Scattered moderate convection is noted from 05N to 14N between 40W and 49W. A tropical wave is in the E Caribbean south of 20N with axis near 64W, moving westward at around 15-20 kt. Scattered moderate convection extends from 10N to 17N between 60W and 67W. A tropical wave is in the far W Caribbean with axis near 85W, moving westward at about 15 kt. The wave appears to enhance convection over Panama, Costa Rica, and far southern Nicaragua. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 19N16W and extends southwestward to 07N45W. Convection is discussed in the Tropical Waves section above. ...GULF OF AMERICA... A 1021 mb high is centered over the northern Gulf, supporting gentle to moderate winds across the forecast waters. Seas are 1-4 ft. Scattered moderate convection is noted in the Bay of Campeche associated with a surface trough. Scattered showers and thunderstorms are also developing across the central Gulf, driven by convergent surface winds. For the forecast, a high pressure center will remain over the north-central Gulf this weekend, then moves SE while weakening some by Mon. This pattern will produce mostly gentle to moderate E to SE winds across the basin, with pulses of fresh winds occurring north and west of the Yucatan Peninsula and into the Bay of Campeche each night, as a surface trough migrates from the Yucatan Peninsula westward across the SW Gulf. Slight to moderate seas are expected through the forecast period. Looking ahead, by midweek next week winds may increase to fresh speeds over the NW and west-central Gulf as the pressure gradient tightens between the high pressure and lower pressures over north-central Mexico. ...CARIBBEAN SEA... See Special Features section for information on the Gale Warning in effect for the south-central basin. See the Tropical Waves section for more info on winds and convection in the E Caribbean. Outside of the gale area, fresh to strong trade winds and rough seas are occurring over much of the Caribbean S of 18N. Moderate to locally fresh E winds prevail over the remaining waters with seas 3-6 ft. A surface trough along the eastern Yucatan Peninsula supports scattered moderate convection from the Gulf of Honduras up along the Yucatan coast. For the forecast, a ridge N of the area combined with the Colombian low will continue to support fresh to strong winds over most of the east and central Caribbean this weekend. Peak winds to minimal gale-force are expected offshore Colombia tonight. A strong tropical wave, with axis near 64W, Invest AL92 , will continue to impact the eastern Caribbean today. Even though development is highly unlikely, strong gusty winds, rough seas and areas of heavy rain are still possible across portions of the Lesser Antilles today. These weather conditions are forecast to shift westward toward the central and SW Caribbean, including the Greater Antilles and the Windward Passage from tonight through Mon. Afterwards, the tropical wave may weaken, as it moves toward the W Caribbean. ...ATLANTIC OCEAN... Ridging prevails across the basin, anchored by a 1023 mb high SE of Bermuda. Along the coast of Western Sahara and through the Canary Islands, NE winds are fresh with seas 6-7 ft. Elsewhere the trades are moderate or weaker with seas 3-6 ft. Scattered moderate convection is occurring along and N of 30N between 55W and 75W as a cold front approaches the discussion waters. For the forecast west of 55W, the Bermuda-Azores High, combined with the passage of two tropical through the Caribbean Sea will cause fresh to strong NE to E winds south of 22N including the approaches and in the Windward Passage from late this afternoon through Sun night. Looking ahead, a cold front will slowly push across the northern forecast border east of 70W late on Sun, causing a wind shift to the NW and then N with fresh to locally strong wind speeds ahead of the front on Sun and Mon north of 28N. The front will stall on Monday before dissipating Tue.