Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Aug 13 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 2100 UTC. ...SPECIAL FEATURES... Tropical Storm Hernan is centered near 17.3N 131.9W at 13/2100 UTC, moving south at 5 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Seas are peaking near 13 ft, or 4 M. Scattered moderate to strong convection is noted within 60 nm in the NE semicircle. Hernan is moving southward at around 5 kt. A gradual turn toward the southwest and then west-southwest is forecast from Friday into this weekend. Strong westerly shear is expected to support gradual weakening tonight. By early Friday, increasing dry mid- level air will further weaken the system. 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 Hernan NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 95W north of 02N, moving west at 10 to 15 kt. Nearby convection is discussed in the ITCZ/monsoon trough section below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 07N94W to 07N102W. The ITCZ extends from 07N102W to 10N122W. Scattered moderate to isolated strong convection is from 06N to 11N between 85W and 104W, from 02N to 14N between 104W and 120W, and from 00N to 10N between 130W and 135W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to locally fresh winds prevail over the Gulf of Tehuantepec. Moderate to locally fresh SW gap winds are impacting the northern Gulf of California. Gentle to moderate winds are found elsewhere. Moderate seas are over the open waters off Mexico, with slight to moderate seas over the Gulf of California. For the forecast, pulses of fresh to strong gap winds are expected across the Gulf of Tehuantepec through early next week. A moderate pressure gradient will promote mostly gentle to moderate winds across the remainder offshore waters of Mexico along with moderate seas. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally strong E gap winds and moderate seas persist across and downstream the Gulf of Papagayo. Gentle to moderate winds and moderate seas in SW swell prevail elsewhere. For the forecast, fresh to strong NE to E gap winds and occasionally rough seas will pulse across the Papagayo region through early next week. Gentle to moderate winds will prevail between the Galapagos Islands and Ecuador, with large southerly swell moving into the region starting tonight and Fri, then again early next week. Light to gentle winds and moderate seas in SW swell are expected elsewhere. ...REMAINDER OF THE AREA... Please see Special Features section above for more on Tropical Storm Hernan. Broad ridging dominates the waters north of 20N. Outside the immediate area impacted by Hernan, the pressure gradient between the ridge, Hernan, and Tropical Storm Lala in the central Pacific is supporting fresh to locally strong winds, and rough seas, from 13N to 21N between 130W and 140W. Rough seas in southerly swell cover the waters S of 05N between 97W and 122W. Gentle to moderate winds, and moderate seas prevail elsewhere. For the forecast, Hernan will move to 16.8N 132.0W Fri morning, weaken to a tropical depression near 16.2N 132.4W Fri afternoon, become a remnant low and move to 15.9N 133.6W Sat morning, 15.4N 135.1W Sat afternoon, 15.0N 136.9W Sun morning, and dissipate Sun afternoon. Elsewhere, southerly swell will maintain rough seas over the discussion waters S of 05N between 95W and 130W through the end of the week. Another set of southerly swell is forecast to bring rough seas to the waters S of 05N between 95W and 120W early next week.