Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Aug 19 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 0150 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 88W from 02N northward to across eastern El Salvador and western Honduras and into the western Caribbean Sea, moving westward at around 20 kt. Scattered moderate isolated strong convection is noted from 05.5N to 11.5N between 84W and 89W. An area of low pressure is forecast o form several hundred nautical miles south-southwest of the coast of southern Mexico around the end of the week. Gradual development of this system is likely thereafter, and a tropical depression is expected to form this weekend while the system moves generally west-northwestward, remaining well offshore of Mexico. The axis of a tropical wave is near 106W south of 17N off the coast of southwestern Mexico, moving quickly westward at around 25 kt. Scattered to numerous moderate isolated strong convection is noted from 06N to 12N between 99W and 106W. Scattered moderate convection is noted from 04N to 06N between 106W and 112W. The axis of a tropical wave is near 134W, from 16N southward, well to the east-southeast of the Hawaiian Islands, moving westward at around 10 kt. Scattered to numerous moderate to strong convection is noted from 03N to 15N between 120W and 140W. Environmental conditions appear conducive for gradual development of this system, and a tropical depression is likely to form towards the end of the week or over the weekend while the system moves generally westward across the western portion of the east Pacific and into the Central Pacific. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1009 mb low pressure over northern Colombia at 09N75W to 08N104W to 05N119W to 09N140W. Other than the convection described above with three tropical waves, scattered moderate isolated strong convection is noted from 11N to 15N between 91W and 103W. ...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. High pressure across the NE Pacific extends a ridge south- southeastward into the regional waters to just west of the Revillagigedo Islands. The pressure gradient between this ridge and low pressure troughing across the Gulf of California is yielding moderate to fresh NW to N winds across the near and offshore of Baja California north of Punta Eugenia, with moderate to fresh SE winds in the central and northern Gulf of California. Meanwhile, a tight pressure gradient over the Gulf of Tehuantepec area yields strong to near gale-force northerly gap winds in the Gulf of Tehuantepec and model guidance shows winds very close to minimal gale-force tonight so occasional gusts cannot be ruled out. Resultant rough seas are there. Winds are moderate or weaker across the remainder of the waters. Seas are 4 to 6 ft across the remainder of the offshore waters, and 1 to 3 ft inside the Gulf of California. For the forecast, northerly gap winds will continue to pulse to strong north winds over the Gulf of Tehuantepec each evening and night through the end of the week, near gale-force with occasional gusts to gale tonight. Seas will occasionally build to rough during periods of strong winds. Low pressure across Baja California will sustain a southerly wind flow across the Gulf of California waters, with fresh to strong winds expected across northern portions there through Wed before gradually diminishing through the remainder of the week. Winds and seas will diminish modestly across the Baja offshore waters through the end of the week as high pressure weakens. Looking ahead, winds and seas are expected to build across the outer offshore waters of southwestern Mexico by Fri into the upcoming weekend in association with a developing area of low pressure, expected to develop 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. Fresh to strong easterly gap winds continue across the Papagayo region this evening and extend downwind to near 90W. Seas there are 5 to 8 ft. Winds are moderate or weaker elsewhere north of the monsoon trough, and moderate to locally fresh south of the monsoon trough. Seas across most of the remainder of the waters north of the Equator are 4 to 6 ft in cross equatorial S to SW swell, and 7 to 9 ft in S to SW swell south of the Equator, highest southwest of the Galapagos Islands. For the forecast, the pressure gradient between high pressure over the northwestern Caribbean and relatively lower pressure over Central America will lead to fresh NE to E gap winds pulsing to strong winds over the Papagayo region each evening and night through the rest of the week and into the weekend, resulting in rough seas. Moderate to fresh winds extending well downwind of Papagayo will impact the outer waters offshore of El Salvador and Guatemala at times. Moderate to fresh southerly winds south of the monsoon trough and across the Galapagos waters will gradually diminish through Thu. Moderate cross-equatorial SW swell moving into the regional waters will continue to merge with larger SE swell dominating the southern Pacific waters well south of the Galapagos to produce rough seas 8 ft and greater S of 01N, and moderate seas elsewhere through Thu before subsiding. ...REMAINDER OF THE AREA... See Tropical Waves section above for information on two tropical waves that have potential for tropical development later this week and into the upcoming weekend. High pressure north of the waters extends a ridge south- southeastward into the regional waters to just west of the Revillagigedo Islands. Moderate to locally fresh NE to E winds are noted from near 10N to 21N between 120W and 140W. Seas are 6 to 9 ft across these waters with a tropical wave helping to enhance conditions there. Moderate to fresh SE to S winds are found south of 05N, with winds mainly moderate or weaker across the remainder of the waters. Seas are 7 to 10 ft south of 05N in mixed long period cross equatorial swell, and mainly 5 to 7 ft across the remainder of the waters, slightly lower in the north- central waters right under the ridging. For the forecast, regardless of tropical development, the tropical waves described above will bring some increasing winds and seas to area waters, as they move south of the current ridge in place. Away from these waves, little change is expected in marine weather through the week and into the upcoming weekend.