Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Aug 21 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 0230 UTC. ...SPECIAL FEATURE... An area of low pressure has developed in the tropical wave environment, analyzed along 114W. The low is centered near 07.5N114W, with minimum pressure of 1008 mb. A large area of disorganized showers and thunderstorms prevails from 02N to 16N between 111W and 120W. Environmental conditions appear favorable for gradual development, and a tropical depression could form this weekend or early next week while the system moves west- northwestward or northwestward at 5 to 10 kt. THis system has a medium chance for tropical formation within 48 hrs and 7 days. Please refer to the latest NHC Tropical Weather Outlook at website: https://www.nhc.noaa.gov/text/MIATWOEP.shtml for more details on these systems. ...TROPICAL WAVES... The axis of a tropical wave is moving over eastern portions of the Tropical Pacific basin along 85W, N of 03N, moving westward at 15 to 20 kt. Scattered moderate to strong convection is noted S of 09N and E of 89W. The axis of a tropical wave is near 100W, N of 05N, moving westward at 10 to 15 kt. Scattered moderate to strong convection stretches from 05N to 15N between 94W and 110W, as the wave interacts with a middle level trough extending off the SW coast of Mexico. Environmental conditions appear favorable for gradual development, and a tropical depression is likely to form this weekend or early next week while the system moves west-northwestward or northwestward, remaining well offshore of Mexico. This system has a high chance for tropical formation within the next 7 days. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 08N137W. Aside from the convection related to the tropical waves described above, scattered moderate convection is noted within 200 nm on either side of the trough. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Tropical Waves section above for information on a tropical wave that has a potential for tropical development offshore Mexico this upcoming weekend, and for related convection. A modest pressure gradient continues across the Gulf of Tehuantepec area, where the northern portion of a tropical wave has moved W of the Gulf, and is producing strong N to NE gap winds in the Gulf and downstream to near 13N98W. Seas are 5 to 7 ft across that area. Across the remainder of the offshore waters of Mexico, typical ridging has been disrupted by a low level trough offshore of Punta Eugenia, along about 118W, resulting in a weak pressure gradient across the region. Latest scatterometer data showed that this current pattern is producing light to gentle NW to N winds, except moderate near Cabo Corrientes. Seas are 4 to 5 ft across the waters away from the Gulf of Tehuantepec. Gentle southerly winds prevail across the far northern Gulf of California, and become gentle NW to N across the remainder of the Gulf. Seas there are 1 to 3 ft. An upper level trough extending offshore of SW Mexico continues to support clusters of strong thunderstorms along the coasts and nearshore waters of Guerrero and Michoacan, and continue to shift westward, ahead of an approaching tropical wave. For the forecast, fresh northerly gap winds will continue to pulse to strong winds over the Gulf of Tehuantepec during the overnight into the early morning hours through the next several days, with seas occasionally building to rough. High pressure will begin to build back modestly across the Baja offshore waters Fri afternoon through Sat night to produce a more typical moderate to fresh NW wind flow there. Southerly wind flow will return to the Gulf of California Sat night and become fresh to locally strong Sun. Winds and seas are expected to build across the outer offshore waters of southwestern Mexico tonight into early next week in association with a developing area of low pressure moving westward and just outside of the offshore waters. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Refer to the Tropical Waves section above for details on any convection. Recent satellite scatterometer data shows fresh to strong NE to E gap extending across the Papagayo region to near 90W, where seas are 5 to 7 ft. Fresh easterly winds then continue westward and downstream, and S of 12.5N, across the outer offshore waters of El Salvador and Guatemala, where seas are 6 to 7 ft. Mainly moderate or weaker winds are found elsewhere, with fresh winds near the border of Peru and Ecuador close to the entrance to the Gulf of Guayaquil. Seas are 4 to 6 ft across the remainder of the waters north of 04N, and 6 to 8 ft south of 04N. Clusters of strong thunderstorms are over the waters south of Panama and Costa Rica, due to the passing tropical wave there, described above. For the forecast, high pressure will persist over the eastern Gulf of America and northwestern Caribbean into early next week, leading to fresh NE to E gap winds pulsing to strong winds 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 at least early next week. South of the monsoon trough, winds will gradually diminish and remain light to gentle through the weekend. Mainly moderate seas will prevail away from the Gulf of Papagayo area through the next several days. Southeasterly swell producing rough seas across the southern waters will subside this evening through Fri. ...REMAINDER OF THE AREA... Please see the Special Features section and the Tropical Waves section above for information on systems that have the potential for tropical cyclone formation, and any associated convection currently present leading to higher winds and seas. High pressure across the NE Pacific extends a ridge south- southeastward into the regional waters to offshore of Baja Surf. Fresh easterly winds and seas to 7 ft are noted in the periphery of Tropical Depression Two-C in the Central Pacific basin are impacting the waters between 10N to 20N and W of 135W. Elsewhere, moderate to fresh trades are found from 10N to 22N between 124W and 140W , where seas are 5 to 7 ft. Moderate to fresh winds are found south of 06N to the east of 118W and south of 04N to the west of 120W. Rough seas over the southern waters are gradually subsiding, and now cover the waters south of 02.5N E of 120W. For the forecast, regardless of tropical development, the features described above will bring increasing winds and seas to area waters south of 25N, as they move south of the current ridge in place. Away from these features, little change is expected in marine weather through the next several days, except for the rough seas over the southern waters, which are forecast to fully subside by the start of the weekend.