Eastern Pacific Tropical Weather Discussion
159 AXPZ20 KNHC 212101 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Oct 21 2026 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2045 UTC. ...SPECIAL FEATURES... Tropical Storm Vance is centered near 9.4N 99.8W at 21/2100 UTC, moving west at 6 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Seas are peaking near 14 ft. Scattered moderate to strong convection is noted within 60 nm of center. Scattered moderate and isolated strong convection is elsewhere from 02N to 15N between 90W and 103W. Vance is moving westward, with a slow forward motion and a turn toward the northwest and then north- northwest forecast. The system is forecast to reach hurricane intensity by Thu night. Swells generated by Vance are expected to begin affecting portions of the coast of southern and southwestern Mexico this weekend and continue into next week. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Twenty-Two NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure over Mexico and TS Vance is supporting near- gale force northerly gap winds funneling into the Gulf of Tehuantepec, accompanied by rough seas. Winds will pulse to gale- force tonight and Thu night across the Gulf of Tehuantepec as TS Vance further intensifies. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N86W to 11N95W. It resumes west of TS Vance near 08N100W to 04N110W. The ITCZ extends from 04N110W 05N140W. Scattered moderate to isolated strong convection is noted from 00N to 08N east of 83W, and from 01N to 09N between 110W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on newly named Tropical Storm Vance and the gale warning in the Gulf of Tehuantepec. Aside from the Gulf of Tehuantepec and TS Vance, light to gentle breezes and moderate seas prevail, except for slight seas in the Gulf of California. For the forecast, newly named Tropical Storm Vance is near 9.4N 99.8W at 2 PM PDT, and is moving west at 6 kt. Maximum sustained winds are 35 kt with gusts to 45 kt, and the minimum central pressure is 1003 mb. Vance will move to 9.5N 100.5W Thu morning, 9.8N 101.3W Thu afternoon, strengthen to a hurricane near 10.4N 102.1W Fri morning, 11.2N 102.7W Fri afternoon, 11.9N 103.1W Sat morning, and 12.8N 103.5W Sat afternoon. Vance will change little in intensity as it moves to near 14.5N 104.3W Sun afternoon. The pressure gradient between high pressure over Mexico and TS Vance is supporting near- gale force northerly gap winds funneling into the Gulf of Tehuantepec, accompanied by rough seas. Winds will pulse to gale- force tonight and Thu night across the Gulf of Tehuantepec as TS Vance further intensifies. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate winds and moderate seas prevail across the discussion waters. For the forecast, fresh winds will pulse nightly in the Papagayo region. Moderate or weaker winds and moderate seas will prevail elsewhere. ...REMAINDER OF THE AREA... See Special Features section above for information on newly named TS Vance. Elsewhere, a 1009 mb low pressure area is centered near 33N123W, with associated cold front extending from 30N120W to 22N130W. Fresh to strong NW winds and rough to very rough seas with maximum wave heights to 14 ft follow the front. Gentle to moderate winds and moderate seas in a mix of swell are noted elsewhere. For the forecast, the front will dissipate through late Thu as it continues to moves westward, with winds and seas diminishing as they spread southward over the waters north of 15N and west of 125W. Gentle to moderate winds and moderate seas will persist elsewhere. Vance will move to 9.5N 100.5W Thu morning, 9.8N 101.3W Thu afternoon, strengthen to a hurricane near 10.4N 102.1W Fri morning, 11.2N 102.7W Fri afternoon, 11.9N 103.1W Sat morning, and 12.8N 103.5W Sat afternoon. Vance will change little in intensity as it moves to near 14.5N 104.3W Sun afternoon.