Eastern Pacific Tropical Weather Discussion
337 AXPZ20 KNHC 201547 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Oct 20 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 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure settled over Mexico will continue to funnel northerly gap winds of gale-force into the Gulf of Tehuantepec through tonight. Seas in these waters are rough. Winds will diminish to strong Wed, but will increase to gales again Thu night though Fri. South of Southern Mexico (Invest EP94): A low-pressure system located a few hundred miles south of the Gulf of Tehuantepec is producing a large area of showers and thunderstorms that are gradually becoming better organized, and a tropical depression is forecast to form during the next day or so. This system is expected to move westward to west-northwestward at 5 to 10 kt during the next few days, remaining well offshore of southern Mexico. There is a high chance of tropical formation of this low within the next 48 hours. 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 10N86W to a 1007 mb low near 10N95W to 04N107W. The ITCZ stretches from 04N107W to beyond 03N140W. Scattered moderate to isolated strong convection is noted from 00N to 15N E of 103W and S of 08N and W of 125W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for information on the Gale Warning in the Gulf of Tehuantepec and on a low pressure south of the Gulf of Tehuantepec that has a potential for tropical development. Elsewhere, a weak pressure gradient is leading to mainly gentle NW winds and moderate seas. For the forecast, high pressure settled over Mexico will continue to funnel northerly gap winds of gale-force into the Gulf of Tehuantepec through tonight. Seas in these waters are rough. Winds will diminish to strong Wed, but will increase to gales again Thu night though Fri. A low-pressure system located a few hundred miles south of the Gulf of Tehuantepec is producing a large area of showers and thunderstorms that are gradually becoming better organized, and a tropical depression is forecast to form during the next day or so. This system is expected to move westward to west- northwestward at 5 to 10 kt during the next few days, remaining well offshore of southern Mexico. There is a high chance of tropical formation of this low within the next 48 hours. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Rough seas coming from gale-force gap winds in the Gulf of Tehuantepec continue to impact waters well offshore Guatemala. Otherwise, gentle to moderate winds and moderate seas prevail. For the forecast, rough seas deriving from gap winds in the Gulf of Tehuantepec will continue well offshore Guatemala through tonight. Winds will pulse nightly to fresh in the Papagayo region, with strong pulses possible late this week. Moderate or weaker winds and moderate seas will prevail. ...REMAINDER OF THE AREA... Fresh to locally strong originating from a gale-force gap wind episode in the Gulf of Tehuantepec are impacting waters as far south as 06N between 94W and 101W, along with rough seas. To the north, a cold front extends along 30N and W of 135W. Fresh winds prevail in the vicinity of the front. Elsewhere, mainly gentle winds and moderate seas prevail. For the forecast, the aforementioned gap winds with continue to bring periods of fresh to strong N winds and rough seas to waters N of 05N between 92W and 103W into mid-week. As the cold front moves S of 30N today, fresh to strong winds and very seas to waters N of 26N through Wed, with rough seas reaching as far south as 20N Thu. A low-pressure system located a few hundred miles south of the Gulf of Tehuantepec is producing a large area of showers and thunderstorms that are gradually becoming better organized, and a tropical depression is forecast to form during the next day or so. This system is expected to move westward to west-northwestward at around 10 mph during the next few days, remaining well offshore of southern Mexico. There is a high chance of tropical formation of this low within the next 48 hours.