Eastern Pacific Tropical Weather Discussion
316 AXPZ20 KNHC 250927 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Aug 25 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 0920 UTC. ...SPECIAL FEATURES... Tropical Storm Iselle is centered near 20.7N 119.9W at 25/0900 UTC, moving northwest at 13 kt. Estimated minimum central pressure is 988 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Peak seas are estimated near 30 ft. Numerous moderate to strong convection is noted from 19N to 24N between 113W and 122W, while scattered moderate convection extends elsewhere from 16N to 19N between 113W and 119W. A turn toward the west-northwest and a slower forward speed is expected later today. Gradual weakening is expected over the next few days, and Iselle is forecast to become a post-tropical remnant low by early Friday. Swells generated by Iselle are affecting the west coast of the Baja California Peninsula, and will continue 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. Former Tropical Depression Ten-E has become Tropical Storm Julio. Tropical Storm Julio is centered near 15.7N 119.8W at 25/0900 UTC, moving north-northeast at 11 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas are 12 ft within 105 nm SE quadrant. Numerous moderate to strong convection is noted from 12N to 16N between 116W and 122W, while scattered to locally numerous moderate convection extends elsewhere from 05N to 12N between 120W and 130W. Julio is moving toward the north-northeast near 13 kt. This general motion with an increase in forward speed is expected today. Slight strengthening is forecast today before Julio becomes absorbed by Tropical Storm Iselle tonight. 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 NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details on these two systems. ...TROPICAL WAVES... A tropical wave is along 102W, from 02N to 16N, moving westward at 10-15 kt. Scattered moderate isolated strong convection is noted from 02N to 13N between 91W and 104W. A tropical wave is along 110W, from 02N to 17N, moving westward at 10 kt. Scattered moderate isolated strong convection is observed from 05N to 18N between 103W and 112W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 07N78W to 09N85W to 06N96W to 11N112W, then resumes SW of Julio from 14N122W to 10N130W and beyond 10N140W. Aside from the convection related to the tropical waves, T.S. Julio and T.S. Iselle described above, scattered moderate to strong convection is noted from 03N to 08N E of 91W, and from 02N to 13N between 129W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more information about T.S. Iselle. Tropical Storm Iselle is near 20.7N 119.9W at 2 AM PDT, and is moving northwest at 13 kt. Maximum sustained winds are 60 kt with gusts to 75 kt, and the minimum central pressure is 988 mb. The proximity of Iselle continue to support light to gentle winds across the Baja California Norte and SW Mexican offshore waters where seas are moderate to 6 ft. Across the outer Baja California Sur offshore waters, fresh to strong SE winds and rough seas from 8 to 16 ft are present. In the Gulf of California, winds are gentle to moderate from the WNW and seas remain slight. Otherwise, fresh to strong N to NE gap winds persist across the Gulf of Tehuantepec and downwind to about 14N with 5 to 9 ft seas. For the forecast, Iselle will move to 21.3N 121.4W this afternoon, 21.9N 123.2W Wed morning, 22.7N 124.9W Wed afternoon, 23.4N 126.8W Thu morning, weaken to a tropical depression near 23.9N 128.8W Thu afternoon, and become a remnant low and move to 24.3N 130.7W Fri morning. Iselle will dissipate early Sat. Large southerly swell associated with Iselle will continue to move through the Baja offshore waters and reach the coasts through Wed night. Elsewhere, fresh northerly gap winds will continue to pulse to strong speeds across Tehuantepec region mainly during the overnight and early morning hours through the upcoming weekend, with seas occasionally building to 8-9 ft. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE to E gap winds continue across the Papagayo region and downwind to near 90W, where seas are 6 to 9 ft. Moderate southerly winds and moderate seas are between the Ecuador and the Galapagos Islands, except W of Isabela and Fernandina Islands where fresh SSE winds are ongoing. Moderate or weaker winds are found elsewhere, with slight to moderate seas in SW swell. For the forecast, moderate to fresh NE to E gap winds will likely pulse to strong speeds over the Papagayo region each night through Sat night building seas to 8-9 ft. Moderate to fresh winds extending well downwind of Papagayo will impact the outer offshore waters of El Salvador and Guatemala through the end of the week. South of the monsoon trough, moderate to locally fresh S winds will diminish to gentle to moderate speeds Tue night and then prevail through the remainder forecast period. Otherwise, cross- equatorial SW swell will move into the area waters Thu night through Fri. ...REMAINDER OF THE AREA... Please see the Special Features section for more information about T.S. Iselle and T.S. Julio. High pressure of 1022 mb located near 31N145W extends a broad ridge southeastward to approximately 125W, just West of Iselle. The pressure gradient between these two features is supporting moderate to locally fresh NE to E winds from 11N to 22N and W of 130W per scatterometer data. Moderate to fresh SW to W winds are south of the monsoon W of 131W while E winds of similar speed are E of the tropical wave near 102W. South of the monsoon and E of 115W SSW winds are moderate to fresh. Elsewhere, winds are moderate or weaker and seas moderate. For the forecast, a tropical wave located near 102W, well to the SW of SW Mexico is producing a large area of disorganized showers and thunderstorms. Environmental conditions appear favorable for development of this system, and a tropical depression is expected to form by the end of the week while it moves generally west- northwestward at 10 to 15 kt, well offshore of Mexico. This system has a low chance for tropical cyclone formation within the next two days and high chance of development through 7 days. Looking ahead, an area of low pressure could form well offshore of Central America late this week or this weekend. Environmental conditions could support some gradual development of this system, and a tropical depression could form late this weekend or early next week while it moves westward to west-northwestward at 10 to 15 mph well offshore of southern Mexico. This system has a low chance for tropical cyclone formation within the next two days and a medium chance of development through 7 days.