Eastern Pacific Tropical Weather Discussion
012 AXPZ20 KNHC 262214 CCA TWDEP Tropical Weather Discussion...Corrected NWS National Hurricane Center Miami FL 2205 UTC Mon Oct 26 2026 Corrected Offshore Waters Within 250 nm of Mexico 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 2145 UTC. ...SPECIAL FEATURES... Tropical Storm Vance is centered near 15.4N 106.1W, or about 240 nm SSW of Manzanillo, Mexico at 26/2100 UTC, moving west at 5 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Peak seas are currently around 23 ft or 7 m. Vance is continuing to be inflicted by westerly vertical wind shear. Satellite imagery shows numerous strong convection within 150 nm of the center in the N semicircle and 30 nm of the center in the S semicircle. Vance is forecast to make a turn to the northwest on Tue, followed by a northward turn on Wed. Gradual weakening is forecast during the next few days. Vance is expected to produce 2 to 4 inches of rain, with isolated higher totals of 7 inches possible, across southern Sinaloa, southwest Durango and coastal sections of Nayarit, Jalisco, Colima and Michoacan. This rainfall may produce flooding and mudslides, especially in areas along steep terrain. Swell generated by Vance will affect portions of the coast of southern, southwestern and west-central Mexico during the next few days. This swell is 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 Vance NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from along the coast of NW Colombia to across central Panama, and continues to 08N82W to 06N90W and to 12N100W. It resumes well southwest of Vance at 09.5N110W to 06N121W to low pressure near 07.5N133W 1012 mb and to 07N140W. Scattered moderate to isolated strong convection is from 03S to 06N between 80W-86W, also from 02N to 07N between 96W-100W. Similar activity is within 120 nm south of trough between 131W-135W, and within 60 nm north of the trough between 133W-135W. Scattered moderate convection is within 60 nm either side of the trough between 120W-122W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...Corrected Please see the Special Features section above for information on Tropical Storm Vance. Latest Ascat scatterometer data reveals that the Gulf of Tehuantepec north to northeast gale-force gap winds have lowered to just below gale-force maxing out to 30 kt. Seas with these winds are 8 to 11 ft. Moderate or lighter winds are elsewhere over the Mexican offshore waters. Seas are 5 to 7 ft in mixed southeast and southwest long-priod swell. The exception is offshore Baja California north of about Punta Eugenia, where mostly moderate northwest to north fresh winds are present as suggested in the latest Ascat scatterometer data pass. Fresh northwest to north winds are just north of 29N. Seas over these waters are 4 to 6 ft. Seas of 3 to 5 ft in southeast long-period swell are out ahead of Vance are in the extreme southern Gulf of California and southward from there to 23N, then increase to 6 to 8 ft toward Cabo Corrientes. For the forecast, Tropical Storm Vance is forecast to gradually weaken as it moves to near 15.6N 106.9W late tonight, to near 16.7N 107.9W Tue afternoon with maximum sustained winds 45 kt gusts 55 kt, to near 18.1N 108.4W late Tue night, to near 19.8N 108.6W Wed afternoon, to near 21.3N 108.4W late Wed night with maximum sustained winds 35 kt gusts 45 kt, then weaken to a remnant low near 22.6N 108.2W Thu afternoon. Vance is forecast to dissipate Fri afternoon. Otherwise, the north to northeast strong to near gale-force gap winds in the Gulf of Tehuantepec are expected to hold steady through tonight, then diminish to fresh to strong speeds early on Tue as the gradient over southeastern Mexico just north of the Tehuantepec region continues to relax. Seas in the Gulf are expected to subside to below 8 ft on Tue. Winds there will then pulse at fresh to strong speeds through Thu night, but over a smaller area downstream of the Gulf. Winds offshore Baja California Norte will change little through late Wed. Moderate, or lighter winds along with moderate seas will prevail elsewhere away from Vance and the Gulf of Tehuantepec, except mainly slight seas in the Gulf of California through late Wed. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The latest Ascat scatterometer data pass highlighted fresh northeast winds in the Gulf of Papagayo and downstream from there to near 09N89W. Seas over these waters are 4 to 6 ft as indicated by a couple of satellite altimeter data passes. The latest Ascat scatterometer data pass also shows moderate to fresh northwest to north winds in the Gulf of Panama. Elsewhere, winds are moderate, or lighter along with mostly moderate seas, except slight seas continue nearshore Colombia. The very active convection that earlier was offshore Ecuador, Colombia and Panama has shifted westward and weakened. For the forecast, the fresh northeast winds in and downstream of the Gulf of Papagayo will pulse to moderate to fresh speeds through the end of the week. The fresh northwest to north winds in the Gulf of Panama will diminish early Tue, then start up late Wed night. Otherwise, moderate or weaker winds and moderate seas will continue elsewhere, except mainly slight nearshore Colombia. Looking ahead, seas may build to a rough state in southwest south of the Equator by the end of the week. ...REMAINDER OF THE AREA... See Special Features section above for information on Tropical Storm Vance. High pressure covers the area generally north of about 18N and west of 110W. A recent Ascat scatterometer data pass indicates moderate to fresh trades from 14N to 18N between 120W and 130W, or rather between the high pressure and a trough that extends northward along 133W to 13N from a weak low pressure of 1010 mb along the monsoon trough. A warm front dips into the northwest part of the area from 30N139W to 28N138W. The related gradient is producing fresh to locally strong southeast to south winds and rough seas just southeast of 30N140W. Winds are moderate, or lighter along with moderate seas across the remainder of the open waters away from Vance. For the forecast, Tropical Storm Vance is forecast to gradually weaken as it moves to near 15.6N 106.9W late tonight, to near 16.7N 107.9W Tue afternoon with maximum sustained winds 45 kt gusts 55 kt, to near 18.1N 108.4W late Tue night, to near 19.8N 108.6W Wed afternoon, to near 21.3N 108.4W late Wed night with maximum sustained winds 35 kt gusts 45 kt, then weaken to a remnant low near 22.6N 108.2W Thu afternoon Elsewhere, moderate or weaker winds and moderate seas will persist into at least late Wed. The fresh to locally strong southeast to south winds over the northwest part of the area will diminish to mostly fresh speeds by early on Wed as the warm front pulls away from the region. A new set of southerly swell will continue to spread into a portion of the south- central waters through late Wed, building seas to the range of 7 to 10 ft south of about 04N and between 105W and 128W by late Wed night. These seas are expected to linger through at least Fri night.