Eastern Pacific Tropical Weather Discussion
399 AXPZ20 KNHC 262124 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Aug 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Tropical Storm Iselle is centered near 22.7N 124.9W at 26/2100 UTC, moving west-northwest at 9 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 18 ft (5.5 m). Scattered moderate isolated strong convection is confined to between 75 nm and 210 nm in the NE quadrant only. Iselle is moving toward the west-northwest and this general motion is expected to continue over the next few days. Steady weakening is expected, and Iselle is forecast to become a post- tropical remnant low by tonight. Swells generated by Iselle will continue to affect the west coast of the Baja California Peninsula for a couple more 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 Iselle NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Central East Pacific (Invest EP93): A broad 1007 mb area of low pressure located well south of southwestern Mexico near 09N107W is producing a large area of showers and thunderstorms that continues to gradually become better organized. Scattered to numerous moderate to strong convection is noted across an expansive area on both sides of the monsoon trough, from 02N to 15N between 77W and 117W. Environmental conditions are expected to support gradual development of this system, and a tropical depression is likely to form during the next day or so while it moves west- northwestward at 10 to 15 kt, well offshore of Mexico. This system has a high chance of tropical cyclone formation within the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook at website: https://www.hurricanes.gov/text/MIATWOEP.shtml for more details. Western East Pacific (Invest EP94): An elongated, 1009 mb broad area of low pressure located well to the east-southeast of the Hawaiian Islands near 10.5N135W is producing disorganized showers and thunderstorms. Widely scattered moderate isolated strong convection is noted within 600 nm in the SE semicircle and 150 nm in the NW semicircle of the low pressure center. Environmental conditions appear conducive for gradual development of this system, and a tropical depression is likely to form late this week or early this weekend while the system drifts to the northeast, then turns westward. This system has a medium chance of tropical cyclone formation within the next 48 hours, and a high chance within the next 7 days. Please refer to the latest NHC Tropical Weather Outlook at website: https://www.hurricanes.gov/text/MIATWOEP.shtml for more details. ...TROPICAL WAVES... The axis of a tropical wave is just east of the discussion waters but approaching, along 77W, moving quickly westward around 20 kt. Any nearby convection is described above with Invest EP93. The axis of a tropical wave is along 88.5W north of 05N to across portions of El Salvador an the Yucatan Peninsula, moving westward around 10 kt. Any nearby convection is described above with Invest EP93. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1007 mb low pressure over northern Colombia near 10N74.5W to 08N88W to 10N100W to 1007 mb low pressure, Invest EP93, near 09N107W to 14N118W, then resumes southeast of Tropical Storm Iselle at 16N119W to 1009 broad low pressure, Invest EP94, near 10.5N135W to beyond 11N140W. Other than the convection mentioned above, isolated to widely scattered moderate to strong is noted within 300 nm south of the monsoon trough between 119W and 128W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more information on low pressure Invest EP93 near 09N107W with the high chance for tropical cyclone formation. Tropical Storm Iselle is well beyond the offshore waters of Baja California. Outer associated swells of 7 to 8 ft are impacting the far Baja California Norte waters near the outer offshore boundary. Meanwhile, fresh to strong northerly gap winds continue to blow in the Gulf of Tehuantepec with seas to 8 ft. Winds are moderate or weaker elsewhere with mainly moderate seas, except slight in the Gulf of California. Active showers and thunderstorms are present over the outer offshore waters areas of southern and southwestern Mexico as described with Invest EP93 in the Special Features section above with locally higher winds and seas possible there. For the forecast, the area of low pressure, Invest EP93, which has a high chance for tropical cyclone formation, will move west-northwest at 10 to 15 kt with the center forecast to stay beyond the offshore waters. However, outer winds and seas are forecast to impact portions of the outer offshore waters of southwestern Mexico to the Revillagigedo Islands late Thursday through at least Sun night. Meanwhile, outer rough swells associated with Tropical Storm Iselle will continue to subside through tonight as the system continues to pull away from the offshore waters of Baja California while weakening. Fresh to strong northerly gap winds will continue to pulse in the Gulf of Tehuantepec through early Sun with locally rough seas there at times. A surge of fresh to strong southeasterly winds likely associated with convective complexes may move up the central and northern Gulf of California both Fri and Sat nights. Looking ahead, another area of low pressure could form this weekend well to the south of southwestern Mexico. Environmental conditions appear favorable for some gradual development of this system, and a tropical depression could form by early next week while it moves westward to west-northwestward at 10 to 15 kt. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong easterly gap winds are in the Gulf of Papagayo well downwind to near 10N93W with 5 to 7 ft seas. Winds are moderate or weaker across the offshore waters, with moderate seas, except slight near the coasts of Colombia and eastern Panama. Active showers and thunderstorms are present over the outer offshore waters areas from Colombia northward as described above with Invest EP93 in the Special Features section, with locally higher winds and seas possible there. For the forecast, easterly fresh to strong gap winds will continue to pulse in the Gulf of Papagayo area through the Sat night, then moderate to fresh thereafter, with associated moderate to fresh winds extending well downwind to the outer offshore waters of El Salvador and Guatemala. Southerly winds may freshen south of the monsoon trough this weekend into early next week. Winds will be moderate or weaker elsewhere with mainly moderate seas. Convection will remain active near the monsoon trough. ...REMAINDER OF THE AREA... Please see the Special Features section for more information about Tropical Storm Iselle, low pressure Invest EP93 with the high chance of tropical cyclone formation, and another broad area of low pressure, Invest EP94 in the far west-central waters, also with the potential for tropical cyclone formation. Otherwise, mainly moderate winds prevail north of the monsoon trough hand west of 110W. South of the monsoon trough, mainly moderate to locally fresh winds prevail across much of the open waters with very active convection present. Seas are mainly moderate, except rough near and south of 03N between 115W and 135W in southwesterly swell. For the forecast, Tropical Storm Iselle will become post-tropical and move to 23.2N 126.2W Thu morning, weaken to a remnant low near 23.9N 127.9W Thu afternoon, 24.6N 129.6W Fri morning, 25.3N 131.1W Fri afternoon, and dissipate Sat morning. Other than the two remaining Special Features areas, Invest EP93 and Invest EP94, above, large southwesterly swell will impact the southern waters through Thu night before decaying. Looking ahead, much larger and more expansive southwesterly swell may impact the southern waters by early next week. Little change is forecast elsewhere away from the Special Features areas.