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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Tropical Storm Iselle is centered near 20.9N 121.1W at 1500 UTC, moving west-northwest at 9 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 28 ft. Numerous moderate to strong convection is noted from 20.5N to 23N between 119W and 121W, while scattered moderate convection extends elsewhere from 20N to 24N between 115W and 122W. This current west- northwest motion is expected to continue for the next couple of days, while Iselle gradually weakens due to continued westerly upper level wind shear. Iselle is forecast to become a post- tropical remnant low by early Friday. S-SW swell generated by Iselle is affecting the offshore waters and west coast of the Baja California Peninsula, and will continue through Wed morning before subsiding quickly. These swells are likely to cause large and powerful surf and life- threatening rip current conditions. Please consult products from your local weather office. Tropical Storm Julio is centered near 18.0N 118.9W at 1500 UTC, moving north-northeast at 19 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas are estimated at 15 ft within 90 nm across the SE quadrant. Numerous moderate to strong convection is noted from 15N to 17.5N between 118.5W and 121W, while scattered moderate isolated strong convection extends elsewhere from 10N to 17N between 117W and 124W. Julio has accelerated its forward motion this morning, and combined with northwesterly upper level wind shear, the center has become exposed to the north of the area of strong convection. Julio is expected to move quickly northward, continue to weaken, and gradually become absorbed within the outer eastern circulation of Iselle this evening through 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 107W, from 07N to 19N, moving westward at 15 kt. Scattered to numerous moderate isolated strong convection is noted from 05N to 14N between 100W and 111W. The tropical wave previously along 110W is gradually merging with the wave now along 107W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N75W to 08N109W, then resumes SW of Julio from 15N122W to low pres near 10N138W 1007 mb to beyond 09.5N140W. 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 02.5N to 08.5N E of 90W, and from 02N to 13N between 90W and 100W. Scattered to locally numerous moderate to strong convection is noted from 04N to 12N between 121W and 143W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more information about T.S. Iselle. Tropical Storm Iselle is moving away from the Mexican offshore waters, located near 20.9N 121.1W at 8 AM PDT, moving west-northwest at 9 kt. Maximum sustained winds are 60 kt with gusts to 75 kt, and the minimum central pressure is 988 mb. The proximity of Iselle continues to disrupt the ridge to its north, and into the Baja offshore waters. This is maintaining light to gentle northerly winds across the Baja California waters and similar N to NE winds across the SW Mexican offshore waters. Seas are 7 to 11 ft in S-SW swell from Iselle across the Baja Sur waters, and 5 to 7 ft across the Baja Norte waters. Seas are 4 to 5 ft elsewhere across the remainder of the Mexican offshore waters W of Puerto Angel. Winds and seas are gradually diminishing across the Revillagigedo Islands and area waters as Iselle gradually moves away from that area, as seas remain around 12 ft. Gentle to moderate NW to W gap winds prevail across central and southern portions of the Gulf of California. A large cluster of strong thunderstorms covers much of the area across the entrance to the Gulf to Las Tres Marias, and are supported by an upper level low pressure system. This activity is shifting northward. Otherwise, fresh to strong N to NE gap winds persist across the Gulf of Tehuantepec and downwind to about 14N with 6 to 8 ft seas. For the forecast, Iselle will continue to move west-northwestward and away from the area waters, while gradually weakening, reaching near 21.4N 122.5W this evening, and 22.0N 124.1W Wed morning. Large S-SW swell from Iselle will continue to move through the Baja waters today through early Wed before quickly subsiding. Elsewhere, fresh northerly gap winds will continue to pulse to strong speeds across Tehuantepec region during the overnight and early morning hours through the upcoming weekend, with seas occasionally building to 8-9 ft. Looking ahead, another tropical wave and developing low pressure area will follow a similar trajectory as Iselle, Thu through the weekend, and impact the outer offshore waters near the Revillagigedo Islands within increasing winds and seas. ...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 8 ft. Moderate southerly winds and moderate seas are S of 03N and between the Ecuador and the Galapagos Islands. Moderate or weaker winds are found elsewhere, with slight to moderate seas in SW swell. Scattered to numerous moderate to strong thunderstorms continue across the waters from 02.5N to 08.5N between Colombia and 90W, including the entrance to the Gulf of Panama, and nearshore waters of western Panama, and Cost Rica. For the forecast, moderate to fresh NE to E gap winds will pulse to strong speeds over the Papagayo region each night through Sat night building seas to around 8 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 1020 mb located near 35N130W extends a broad ridge south and southeastward to approximately 118W, and drapes across Iselle. The pressure gradient between these features and low pressure associated with the monsoon trough is supporting moderate to locally fresh NE to E winds from 10N to 25N and W of 130W per recent satellite scatterometer data. Moderate to fresh SW to W winds are south of the monsoon W of 131W while moderate to fresh E winds accompany the tropical wave near 107W. South of the monsoon trough and between 115W and 125W, fresh S-SW winds are feeding into Julio and the eastern side of Iselle. Elsewhere, winds are moderate or weaker and seas moderate. For the forecast, Tropical Storm Julio will move northward, weaken and gradually become absorbed in the larger circulation of Iselle, as Iselle shifts west-northwestward between 20N and 25N, before dissipating Fri. A tropical wave located near 107W, 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.