Eastern Pacific Tropical Weather Discussion
821 AXPZ20 KNHC 261541 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Oct 26 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 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...SPECIAL FEATURES... Tropical Storm Vance is centered near 15.4N 105.7W, or about 230 nm SSW of Manzanillo, Mexico at 26/1500 UTC, moving west- northwest at 6 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 still being impacted by west to southwest vertical wind shear. Satellite imagery shows numerous strong convection within 150 nm of the center in the NE semicircle and 30 nm of the center in the SW semicircle of the center. Vance is forecast to maintain its present motion for the next day or so, followed by a turn to the northwest on Tue and north on Wed. Gradual weakening is forecast during the next several 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. Gulf of Tehuantepec Gale Warning: A tight pressure gradient over Mexico from strong high pressure ridging is currently supporting north to northeast winds of 25 to 35 kt in the Gulf of Tehuantepec as detected by overnight Ascat scatterometer data. These winds are forecast to diminish to just below gale force by early this afternoon as the gradient slackens some. Resultant locally rough seas will slowly subside through Tue. 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 axis extends from NW Colombia to across southern Panama, and continues to 08N79W to 09N90W and to 12N100W. It resumes well to the southwest of Vance at 09N110W to 07N120W to low pressure near 09N130W 1010 mb and to 06N140W. Numerous moderate to strong convection is from 01N to 08N between 92W-100W. Scattered moderate to isolated strong convection is within 60 nm south of the trough between 132W-135W. Scattered moderate convection is within 60 nm south of the trough between 110W-113W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on Tropical Storm Vance, and on a soon to end Gale Warning for the Gulf of Tehuantepec. Aside from the Gulf of Tehuantepec and Tropical Storm Vance, winds are moderate or weaker, except locally fresh offshore Baja California from near Punta Eugenia northward. Seas are moderate away from Vance and the Gulf of Tehuantepec region, except slight in the Gulf of California away from the entrance where they are higher due to SE swells moving in from Vance. For the forecast, Tropical Storm Vance is forecast to gradually weaken as it moves to near 15.7N 106.6W this evening, to near 16.4N 107.6W Tue morning with maximum sustained winds 40 kt gusts 50 kt, maintain intensity as it nears 17.6N 108.2W Tue evening, to near 19.2N 108.4W Wed morning, to near 20.7N 108.4W Wed evening with maximum sustained winds 35 kt gusts 45 kt, and weaken to a remnant low near 22.0N 108.2W Thu morning. Vance will change little in intensity as it moves to near 24.1N 108.0W early on Fri. Elsewhere, north to northeast gale-force gap winds in the Gulf of Tehuantepec are expected to diminish to just below gale force by early this afternoon as the gradient slackens some. Resultant seas will slowly subside through Tue. Winds there will then pulse at fresh to strong speeds through Thu night. Moderate to fresh winds will pulse nearshore Baja California Norte through Tue evening. Moderate or weaker 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. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong northeast winds and moderate seas are over and downstream the Gulf of Papagayo while fresh northwest to north winds are in the Gulf of Panama. Winds are moderate or weaker elsewhere with moderate seas, except slight seas nearshore Colombia. Very active convection remains present offshore Ecuador, Colombia and Panama as described above with locally higher winds and seas possible. For the forecast, the present fresh to strong northeast winds over and downstream of the Gulf of Papagayo will diminish to mostly fresh speeds this afternoon, then 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 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 19N and west of 110W. Overnight Ascat scatterometer data indicated moderate to fresh northeast to east winds from 14N to 18N between 120W and 130W, or rather between the high pressure and northward troughing along the monsoon trough near 130W. A frontal system is just west-northwest of 30N140W. The associated warm front reaches southeastward from 30N140W 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 weaker 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 15.7N 106.6W this evening, to near 16.4N 107.6W Tue morning with maximum sustained winds 40 kt gusts 50 kt, maintain intensity as it nears 17.6N 108.2W Tue evening, to near 19.2N 108.4W Wed morning, to near 20.7N 108.4W Wed evening with maximum sustained winds 35 kt gusts 45 kt, and weaken to a remnant low near 22.0N 108.2W Thu morning. Vance will change little in intensity as it moves to near 24.1N 108.0W early on Fri. Elsewhere, moderate or weaker winds and moderate seas will persist into around the middle part of the week. Swells generated from a frontal system just WNW of the discussion waters will support with fresh to locally strong SE to S winds over the far NW portion of the area into the early part of the week. These conditions will spread slightly eastward over the waters roughly north of about 28N and west of 138W through Wed. Meanwhile, a new set of southerly swell is expected to spread into the S-central waters later today, building seas to a rough state over the waters south of about 05N between 105W and 130W by late Wed night. These seas are expected to linger through at least Fri night.