Eastern Pacific Tropical Weather Discussion
950 AXPZ20 KNHC 242155 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Aug 24 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 2030 UTC. ...SPECIAL FEATURES... Tropical Storm Iselle: At 2100 UTC, the center of Iselle was located near 19.2N 118.0W at 2100 UTC, moving northwest at 11 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 26 ft. Numerous moderate to strong convection is noted from 18N to 21.5N between 115W and 119W, while scattered to locally numerous moderate isolated strong convection extends elsewhere from 14N to 23N between 109W and 120W. Iselle is expected to continue moving northwestward through tonight, followed by a gradual turn toward the west-northwest on Tuesday. Some strengthening is expected tonight through Tue, and Iselle is expected to become a short- lived hurricane late tonight through Tue. Gradual weakening is then forecast starting on Tuesday as Iselle encounters increasing upper level wind shear. Swell generated by Iselle has begun to reach the west coast of the Baja California Peninsula today and will spread northward and build across the Baja waters and coasts today through Tue night, then subside on Wed. This S-SW swell will likely produce large and powerful surf and life-threatening rip current conditions. Please consult products from your local weather office. Tropical Depression Ten-E: The small area of low pressure located well to the southwest of the southern tip of the Baja California Peninsula, and to the SW of Iselle, has be classified as Tropical Depression Ten-E. Showers and thunderstorms have increased significantly near the center today, with numerous moderate to strong convection occurring within 75 nm of the center. At 2100 UTC, the center Ten-E was located near 13.5N 120.8W, moving north at 7 kt. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Minimum central pressure is 1006 mb. Ten-E is expected to move north- northeastward later tonight through Tue and begin to accelerate. Some strengthening is expected, and Ten-E is forecast to become a tropical storm tonight through Tue. Ten-E will gradually become entrained in the broader circulation of Iselle, and move northward towards the southeastern side of Iselle. As this occurs, the same vertical wind shear that will lead to the weakening of Iselle, will lead to the weakening and dissipation of the much smaller Ten-E by Wed. 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 99W, from 03N to 17N, moving westward at 15 to 20 kt. Scattered to locally numerous moderate isolated strong convection is noted from 02.5N to 17N between 93W and 103W. A tropical wave is along 107W, from 05N to 18N, moving westward at 15 kt. Scattered moderate convection is observed from 08N to 16N between 103W and 110W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09.5N74.5W to 07N80W to 09N94W to 05.5N104W to 09N111W, then resumes SW of Iselle from 15N120W to low pres near 13N121W 1006 mb to 11N124W to 11N133W to beyond 07N140W. Aside from the convection related to the tropical waves, T.D. Ten-E and T.S. Iselle described above, scattered moderate isolated strong convection is noted from 04.5N to 10N E of 93W. Scattered moderate to strong convection is noted from 02.5N to 15N W of 118W. ...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 19.2N 118.0W at 2 PM PDT, moving northwest at 11 kt. Maximum sustained winds are 60 kt with gusts to 75 kt, and the minimum central pressure is 988 mb. Iselle has weakened the ridge extending into the Baja offshore waters, leading to light to gentle winds across the Baja offshore waters N of 22.5N extending into the coast. Strong to Tropical Storm force winds and very rough seas associated with Iselle are affecting the outer offshore waters S of 22N and W of 112W, and across the Revillagigedo Islands. S-SW swell from Iselle has begun to reach the coast of Baja Sur, with seas across those near shore waters 6 to 8 ft increasing to 9 to 15 ft across the outer periphery of Iselle to the east. Moderate to fresh SE winds and moderate seas have shifted westward across the outer offshore waters of Jalisco, while moderate to fresh NW winds prevail along the coasts of Michoacan. Seas over these SW offshores are moderate in SE swell. Otherwise, fresh to locally strong N to NE gap winds persist across the Gulf of Tehuantepec and downwind to about 14N with seas to 7 ft. Scattered to numerous thunderstorms associated with a tropical wave are shifting northwestward across the nearshore waters of western Oaxaca and Guerrero and are moving inland. For the forecast, Iselle will continue moving northwestward and exit the Mexican offshore waters this evening, reaching near 20.1N 119.4 as a minimal hurricane tonight, reach near 20.9N 121.3W Tue midday, then steadily weaken to a tropical storm near 21.4N 123.2W Tue night, reach near 21.9N 124.9W midday Wed, then continue west-northwestward, reaching near 22.9N 128.9W midday Thu as a post-tropical remnant low. Large southerly swell will move through the Baja offshore waters and reach the coasts through Wed morning. 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 ft. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E gap winds continue across the Papagayo region and downwind to near 91W, where seas are 6 to 8 ft. Moderate to locally fresh winds then continue to near 95W. Moderate or weaker winds are found elsewhere, with moderate seas 5 ft or less in S swell. Scattered thunderstorms extends from the coast of SE Costa Rica and western Panama westward to 90W, while a cluster of strong thunderstorms is just offshore of the coast of Colombia along 06N. For the forecast, high pressure will persist over the eastern Gulf of America and northwestern Caribbean throughout the upcoming week, leading to fresh NE to E gap winds pulsing to strong speeds over the Papagayo region each evening and night. Moderate to fresh winds extending well downwind of Papagayo will impact the outer waters offshore of El Salvador and Guatemala through the end of the week. South of the monsoon trough, gentle to locally moderate winds will persist through Fri night. 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 newly formed Tropical Depression Ten-E. High pressure of 1021 mb located near 32N140W extends a broad ridge southeastward across the northern forecast waters to offshore of Baja Norte. Under the influence of this system, and west of Iselle, moderate to locally fresh N to NE winds are observed from 11N to 26N and W of 120W. Moderate or weaker winds and moderate seas in mixed swell prevail elsewhere to the north, while gentle to moderate southerly winds prevail S of the monsoon trough. For the forecast, Tropical Storm Iselle will continue moving northwestward and reach near 20.1N 119.4 as a minimal hurricane tonight, reach near 20.9N 121.3W Tue midday, then steadily weaken to a tropical storm near 21.4N 123.2W Tue night, reaching near 21.9N 124.9W midday Wed, then continue west- northwestward, reaching near 22.9N 128.9W midday Thu as a post-tropical remnant low. An area of low pressure is expected to develop well south of the southern tip of the Baja California Peninsula during the middle part of the week. Gradual development is expected thereafter, and a tropical depression is likely to form later this week or over the weekend while the system moves generally west-northwestward at 10 to 15 kt. Looking ahead, another area of low pressure could form well offshore of Central America late this week. Environmental conditions appear conducive for some gradual development of this system over the weekend 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 through 7 days.