Eastern Pacific Tropical Weather Discussion
247 AXPZ20 KNHC 280837 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Oct 28 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 0600 UTC surface analysis and satellite imagery through 0600 UTC. ...SPECIAL FEATURES... Tropical Storm Vance is centered near 18.6N 108.6W at 28/0900 UTC, moving north at 10 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are currently around 12-13 ft or 4 m. Vance remains a sheared tropical cyclone with convection limited to the NE to E side of the system with some new deep convection having developed in the past several hours. Numerous moderate to strong convection is noted within 240 nm in the NE semicircle of Vance and 0 nm elsewhere. Vance is moving toward the north. A turn toward the north-northeast is expected later today. Little change in strength is forecast during the next 24 h, followed by gradual weakening. Vance is expected to become a post-tropical remnant low on Thu as it approaches the coast of northwestern Mexico. 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 central and southern Sinaloa, western Durango, and northwestern Nayarit, especially in areas along steep terrain. Swells generated by Vance will affect coastal portions of southwestern, west-central Mexico, and the southern portion of the Baja California Peninsula 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the SW Caribbean Sea near 12N74W to 05N86W to 08N98W well SE of Tropical Storm Vance, then resumes well SW of Vance from 07N114W to 06N126W to 1011 mb low pressure near 08N136.5W to 06N140W. Scattered moderate isolated strong convection is noted from 12N to 17N between 124W and 129W, and from 00N to 10N between 133W and 140W. Isolated to widely scattered moderate convection is noted in a band within 02N117W to 13N105W to 17N106W to 17N103W to 11N103W to 02N117W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on Tropical Storm Vance. Northerly winds in the Gulf of Tehuantepec are fresh to near gale force with seas to rough. Light to gentle winds, and slight to moderate seas, prevail in the Gulf of California. Elsewhere, outside of Vance and the Gulf of Tehuantepec, winds are mainly moderate or weaker, with moderate seas, over the open waters off Mexico, except locally fresh winds nearshore Baja California per recent ASCAT scatterometer data. For the forecast, Tropical Storm Vance will move to 20.0N 108.7W this afternoon, 21.6N 108.3W Thu morning, weaken to a remnant low near 23.1N 108.0W Thu afternoon, inland to 25.2N 107.1W Fri morning, and dissipate Fri afternoon. Winds in the Gulf of Tehuantepec will pulse fresh to near gale force through early Fri, then moderate to fresh through Sat night, then fresh to strong thereafter. 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 or weaker winds and moderate seas generally prevail, locally fresh in the Gulf of Papagayo and the Gulf of Panama. Scattered showers with some isolated thunderstorms prevail across the waters from southern Costa Rica southward to Ecuador. For the forecast, NE winds over 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, locally strong at times this weekend. Moderate to fresh northerly winds will pulse in the Gulf of Panama through the end of the week. Moderate or weaker winds and moderate seas will continue elsewhere, except mainly slight nearshore Colombia. Seas may briefly build to rough in SW swell S of the Equator by the end of the week as winds freshen there on Fri. ...REMAINDER OF THE AREA... See Special Features section above for information on Tropical Storm Vance. A slow moving cold front is over the far NW waters with nearby convection now confined to N of the discussion waters. Fresh to strong winds and rough seas are within 60 nm east of the front. High pressure prevails elsewhere N of about 20N. The pressure gradient between the area of high pressure and the monsoon trough is supporting moderate to locally fresh tradewinds from 14N to 18N and between 124W and 137W per recent ASCAT scatterometer data. Moderate seas are found over these waters. Moderate to fresh winds, and rough seas are found S of 04N between 100W and 120W. Across the remainder of the waters, winds are moderate or weaker with moderate seas. For the forecast, Tropical Storm Vance will move to 20.0N 108.7W this afternoon, 21.6N 108.3W Thu morning, weaken to a remnant low near 23.1N 108.0W Thu afternoon, inland to 25.2N 107.1W Fri morning, and dissipate Fri afternoon. Fresh to locally strong SE to S winds over the NW part of the area will diminish to mostly fresh speeds by tonight. Cross equatorial SW swell will spread northward through mid-week, building seas to 7-10 ft S of 04N between 105W and 128W by late tonight, while mixing with NE swells generated by Vance. These rough 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. 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.