Eastern Pacific Tropical Weather Discussion
340 AXPZ20 KNHC 270240 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Oct 27 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 0000 UTC surface analysis and satellite imagery through 0150 UTC. ...SPECIAL FEATURES... Tropical Storm Vance is centered near 15.5N 106.3W at 27/0300 UTC, moving west at 4 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas are currently around 20 ft or 6.0 m. Vance is a sheared tropical cyclone with numerous moderate to strong convection within 270 nm in the NE quadrant and 240 nm in the SE quadrant, with no convection in the W semicircle due to the shear. Vance is moving toward the west. A turn to the northwest is expected on Tue, followed by a northward turn on Wed. Gradual weakening is forecast during the next few days. Periods of heavy rainfall associated with Vance will impact portions of western Mexico during much of this week. This rainfall may produce flooding and mudslides across southern Sinaloa, southwest Durango, and coastal sections of Nayarit and Jalisco, especially in areas along steep terrain. Swells generated by Vance will affect portions of the coast of southern, southwestern and west-central Mexico during the next few days. 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 Vance NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gulf of Tehuantepec Gale Warning: A tight pressure gradient over the region along with nocturnal drainage flow is resulting in N-NE minimal gale force winds in the Gulf of Tehuantepec with rough seas. Winds are forecast to diminish below gale force by mid-morning 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 09N76W to 07N99W to well SE of Tropical Storm Vance at 09N102W. It resumes well SW of Vance at 09N109W to 05N129W to 1010 mb low pressure near 07N133W to 04N140W. Scattered moderate isolated strong convection is noted from 02S to 07N between 80W and 92W. Isolated to widely scattered moderate convection is noted from 00N to 09N between 98W and 110W, and from 00N to 10N between 127W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on Tropical Storm Vance and on a Gale Warning in the Gulf of Tehuantepec. Away from Vance and the Gulf of Tehuantepec, winds are mainly moderate or weaker, except locally fresh offshore Baja California Norte. Seas are moderate away from those Special Features areas, except slight in the northern and central Gulf of California, higher in the SE Gulf due to swells associated with Vance. For the forecast, Tropical Storm Vance will move to 15.9N 107.1W Tue morning, 17.2N 107.9W Tue evening, 18.8N 108.3W Wed morning, 20.5N 108.3W Wed evening, 22.0N 108.1W Thu morning, and weaken to a remnant low near 23.5N 107.6W Thu evening. Vance will dissipate late Fri. Gale force northerly winds in the Gulf of Tehuantepec will diminish to fresh to near gale force Tue mid- morning, pulsing at those speeds through Thu night, then pulsing at moderate to fresh thereafter. Moderate to locally fresh winds offshore Baja California Norte will diminish Wed. Looking ahead, a developing low pressure and frontal system may impact the Baja California Peninsula waters late in the upcoming weekend with the potential for increasing winds and building seas. Moderate or weaker winds and moderate seas will prevail otherwise. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE winds are in and downwind of the Gulf of Papagayo. Moderate to fresh NW to N winds are in the Gulf of Panama. Moderate seas dominate the offshore waters, except slight nearshore Colombia. Active convection is present along the coast and inland of Colombia and Ecuador, and well offshore of those waters also with the potential for locally higher winds and seas. For the forecast, fresh NE winds in and downstream of the Gulf of Papagayo will pulse to moderate to fresh speeds through the end of the week and into the upcoming weekend. Moderate to fresh northerly winds will pulse in the Gulf of Panama through the end of the week, locally strong at times through mid-week. 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 SW swell S 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. A frontal system remains mainly WNW of the area, with an associated cold front touching 30N140W. Fresh to strong SE to S winds and rough seas are just ahead of the front in the far NW waters just SE of 30N140W. Meanwhile, 1010 mb low pressure is embedded in the monsoon trough near 07N133W with a surface trough analyzed off to the NE. The pressure gradient between these features and the high supports moderate to fresh trades from roughly 14N to 20N between 115W and 135W. Winds are moderate or weaker across the remainder of the open waters, except locally fresh S of the Equator and E of 115W. Moderate seas prevail away from Vance and the NW corner, except to rough S of 02N between 95W and 120W in incoming SW swell mixing with NE swells generated from Tropical Storm Vance. For the forecast, Tropical Storm Vance will move to 15.9N 107.1W Tue morning, 17.2N 107.9W Tue evening, 18.8N 108.3W Wed morning, 20.5N 108.3W Wed evening, 22.0N 108.1W Thu morning, and weaken to a remnant low near 23.5N 107.6W Thu evening. Vance will dissipate late Fri. Meanwhile, fresh to locally strong SE to S winds over the NW part of the area will diminish to mostly fresh speeds by early on Wed as the warm front pulls away from the region. Incoming SW swell will continue to spread into a portion of the S-central waters through late Wed, building seas to the range of 7-10 ft S of about 04N and between 105W and 128W by late Wed night, while mixing with old NE swells generated by Vance. These seas are expected to linger through at least Fri night, likely subsiding by the start of the weekend. Elsewhere, moderate or weaker winds and moderate seas will persist through at least mid-week. Looking ahead, a developing low pressure and frontal system may impact the waters N of 20N by the end of the week into the upcoming weekend with the potential for increasing winds and building seas as the system shifts eastward.