Eastern Pacific Tropical Weather Discussion
073 AXPZ20 KNHC 120353 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Sep 12 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 17.2N 126.6W at 12/0300 UTC, moving west-northwest at 10 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Peak seas are 24 ft within 150 nm NE quadrant of the center. Numerous moderate to strong convection is noted from within 180 nm NE and 90 nm SW semicircles. Norbert will continue to move to the west- northwest over the next couple of days. Some strengthening is forecast during the next 48 hours, and Norbert could become a hurricane by late Sat. 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 (EP97): Showers and thunderstorms continue to become better organized in association with a broad area of low pressure located several hundred miles southwest of the southwestern coast of Mexico. Gradual development of this system is likely, and a tropical depression is expected to form during the next day or two 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. Regardless of tropical cyclone development, winds to minimal gale-force along with rough seas are expected about 120 nm south and southwest of Clarion Island by late Sun. Refer to the latest NHC Tropical Weather Outlook at website - www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 86W north of 08N, moving west at 10 to 15 kt. Scattered moderate convection is active from 05N to 08N between 83W and 87W. A tropical wave is along 113W/114W from 07N to 20N, moving westward at 10 to 15 kt. A 1009 mb surface low (EP97) is along the wave axis near 14N114W. Scattered moderate convection is present from 11N to 14N between 111W and 117W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N78W to 09N85W to 10N110W to 16N118W, and from 12N125W to 15N140W. In addition to the convection associated with T.S. Norbert and Invest EP97, scattered moderate convection is found from 06N to 11N between 90W and 100W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more information about Tropical Storm Norbert and Invest EP97. Fresh to strong winds and building seas are likely within 120 nm to the northeast of the 1008 mb low pressure area near 14N114W, reaching the outer offshore waters south of the Revillagigedo Islands. Farther north, 1000 mb low pressure is analyzed over the Colorado River Valley between California and Arizona. This pattern is supporting moderate to possibly locally fresh SE winds across the northern Gulf of California. Gentle to moderate winds and 3-5 ft seas are noted elsewhere. For the forecast, 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 likely due to the pressure gradient between the ridge and the meandering trough that is in place in that area. Fresh to strong N to NE gap winds will pulse again in the Tehuantepec region early next week. Meanwhile, showers and thunderstorms are becoming better organized in association with a broad area of low pressure (EP97) located several miles southwest of the southwestern coast of Mexico. Gradual development of this system is likely, and a tropical depression is expected to form late this weekend or early next week while it moves generally west- northwestward to westward over the central and western portions of the East Pacific. Regardless of tropical development, interests south of the Clarion Island may see fresh to strong SE winds and rough seas by late Sun as the low pressure moves W-NW to the south of the island. ...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 89W. Elsewhere, moderate or weaker winds and moderate seas are prevalent. Scattered showers and thunderstorms are occurring off Panama and Colombia. Gusty winds and higher seas are likely occurring with these storms. 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 130W. 1020 mb high pressure located 32N132W dominates 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, Tropical Storm Norbert is near 17.2N 126.6W at 8 PM PDT, and is moving west-northwest at 10 kt. Maximum sustained winds are 55 kt with gusts to 65 kt, and the minimum central pressure is 996 mb. Norbert will move to 17.4N 127.9W Sat morning, strengthen to a hurricane near 17.8N 129.8W Sat evening, 18.2N 131.5W Sun morning, 18.5N 133.3W Sun evening, weaken to a tropical storm near 18.7N 135.5W Mon morning, and 18.6N 137.3W Mon evening. Norbert will change little in intensity as it moves to the west of 140W by late Tue. 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.