Eastern Pacific Tropical Weather Discussion
996 AXPZ20 KNHC 130339 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sun Sep 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Tropical Storm Norbert is centered near 17.9N 130.5W at 13/0300 UTC, moving west at 10 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas are 22 ft within 90 nm NW semicircle of the center. Numerous moderate to scattered strong convection is noted within 150 nm NW semicircle. Norbert is moving toward the west- northwest. Norbert will continue on a westward track during the next several days, with little change in the intensity through the next 24 to 36 hours, then gradual weakening thereafter. Norbert should degenerate into a post- tropical remnant low toward the end of next week. 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 Fourteen-E NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gale Warning south of Clarion Island (Invest EP97): Showers and thunderstorms associated with an area of low pressure located several hundred miles southwest of the southwestern coast of Mexico remain disorganized. Environmental conditions appear conducive for development, however, and a tropical depression is expected to form during the next couple of days while it moves generally west-northwestward to westward over the central and western portions of the eastern Pacific basin. This system has a high chance of tropical cyclone formation within the next 48 hours. A Gale Warning is in effect with this system. Regardless of tropical cyclone development, winds strong winds with rough seas are expected to the south and southwest of Clarion Island through Mon. Refer to the latest NHC Tropical Weather Outlook at website - www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 95W north of 03N extending into Oaxaca, moving west at 10 to 15 kt. Associated convection is described below in the ITCZ/Monsoon Trough section. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 07N100W to 09N110W, and from 12N130W to beyond 13N140W. In addition to the convection associated with T.S. Norbert and Invest EP97, scattered moderate convection is active from 03N to 06N between 82W and 90W, from 06N to 09N between 90W and 100W, and from 08N to 11N between 135W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more information about Tropical Storm Norbert and Invest EP97. Fresh NW winds and seas to six feet are likely ongoing off Cabo Corrientes currently. Elsewhere, and aside from the winds and seas already described near Clarion Island, gentle breezes and 2-4 ft seas prevail across Mexican offshore waters. For the forecast, away from the impacts of Invest EP97, a ridge will build across the offshore waters of Baja California, bringing moderate to locally fresh NW to N winds Sun into early next week. Expect fresh winds across the northern Gulf of California early next week due to the pressure gradient between the ridge and lower pressure over the Colorado River valley. Looking ahead, fresh to strong N to NE gap winds will pulse again in the Tehuantepec region by the middle of next week, building seas to 8 or 9 ft. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... High pressure north of the area is promoting fresh to strong easterly trade winds and rough seas across the Gulf of Papagayo region, extending downstream to near 90W. Elsewhere, moderate or weaker winds and moderate seas are prevalent. Convection continues to develop on either side of the monsoon trough. Gusty winds and higher seas are likely occurring near thunderstorms. For the forecast, a ridge north of the area will continue to support pulsing fresh to strong easterly winds and moderate to rough seas across the Papagayo region through early next week. Meanwhile, gentle to moderate southerly winds and moderate seas are expected over the waters between Ecuador and the Galapagos through at least the middle of next week. Moderate or lighter winds and moderate seas in long period SW swell are forecast elsewhere. ...REMAINDER OF THE AREA... Please see the Special Features section for more information about Tropical Storm Norbert and Invest EP97. Away from the impacts of T.S. Norbert, moderate to locally fresh SE winds and rough seas are found south of 04N and west of the Galapagos Islands to about 135W. A 1019 mb high pressure located N of area near 32N131W dominates the waters north of 20N. Under the influence of this system, and away from Norbert, mainly moderate winds and moderate seas prevail, with the exception of light to gentle winds north of 20N and east of 115W to Baja California Peninsula. For the forecast, Norbert will move to 18.3N 132.0W Sun morning, 18.7N 134.2W Sun evening, 19.1N 136.6W Mon morning, 19.3N 139.4W Mon evening, then continue to weaken as it moves west of 140W, before dissipating late Wed. Elsewhere, a cross equatorial swell will persist over the next several days producing seas to 9 ft south of 04N. A tight pressure gradient will result in locally fresh N winds and rough seas in the NE waters late this weekend into early next week.