Eastern Pacific Tropical Weather Discussion
601 AXPZ20 KNHC 270420 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Aug 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 0300 UTC. ...SPECIAL FEATURES... Post-Tropical Cyclone Iselle is centered near 23.0N 125.9W at 27/0300 UTC, moving west-northwest at 8 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are currently around 14 ft (4.5 m). No significant convection is noted near the center of Iselle. Iselle should continue to move west-northwestward over the next couple of days, steered by a mid-level ridge to the north of the cyclone. Increasing wind shear, cooler sea surface temperatures, and a drier air mass will continue to weaken the system. The post-tropical remnant low is expected to gradually spin down and open into a trough in about 2 to 3 days. 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 area of low pressure located well south of southwestern Mexico continues to produce a large area of showers and thunderstorms. Although the system has not become better organized over the last several hours, environmental conditions are still expected to support gradual development of this system, and a tropical depression is likely to form tonight or on Thursday. The system is forecast to move west-northwestward at 10 to 15 mph, 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 area of low pressure located well to the east-southeast of the Hawaiian Islands has become slightly better organized over the last several hours. 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, before turning westward by early next week. 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 along 89W north of 05N to across portions of El Salvador, moving westward around 10 kt. Any nearby convection is described below in the Intertropical Convergence Zone/Monsoon Trough section below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N79W to 07N90W to 1006 mb low pressure (EP93) near 09N108W to 14N160W, and from 14N130W to low pressure near 1008 mb near 11N135W to 10N140W. Scattered moderate to isolated strong convection is active from 04N13N between 85W to 135W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more information on low pressure Invest EP93 near 09N108W with the high chance for tropical cyclone formation. Post-Tropical Cyclone 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, centered well southwest of southern Mexico has a chance for tropical cyclone formation, but stay outside of the offshore waters as it moves wes-northwestward at 10 to 15 kt Sun. The center of the low pressure will make its closest point of approach within 120 nm to the southwest of Clarion Island Fri night into Sat. 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, Post-Tropical Cyclone Iselle will become a remnant low and move to 23.6N 127.2W Thu morning, 24.3N 128.8W Thu evening, 24.8N 130.2W Fri morning, 25.3N 131.6W Fri evening, 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.