Eastern Pacific Tropical Weather Discussion
925 AXPZ20 KNHC 120917 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Tropical Storm Norbert is centered near 17.1N 127.4W at 12/0900 UTC, moving west-northwest at 8 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 50 kt with gusts to 60 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. Environmental conditions remain favorable for some strengthening over the weekend, and Norbert is forecast to approach hurricane intensity by 24 to 36 hours. Thereafter, a gradual weakening trend is forecast through the remainder of the period. 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 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 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 89W north of 08N, moving west at 10 to 15 kt. Scattered moderate convection is active from 10N to 13N between 88W and 91W. A tropical wave is along 114W from 07N to 20N, moving westward at 10 to 15 kt. A 1006 mb surface low (EP97) is along the wave axis near 14N114W. Scattered moderate convection is present from 12N to 15N between 110W and 117W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 07N95W to 16N115W to 15N120W, and from 13N125W to 09N135W to 14N140W. 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. A recent scatterometer satellite pass confirmed fresh to strong winds near 1006 mb low pressure, Invest EP97, south of Clarion Island near 15N114W. Moderate to rough seas accompany these winds. The scatterometer pass also showed moderate to locally fresh NW winds off the coast of Colima and Michoacan. Farther north, 1003 mb low pressure is analyzed over the Colorado River Valley between California and Arizona. This pattern is supporting moderate to fresh SE winds across the northern Gulf of California, as noted in the scatterometer satellite pass. Gentle to moderate winds and 3-5 ft seas are noted elsewhere. For the forecast, showers and thunderstorms associated with the broad area of low pressure, Invest EP97, located south of Clarion Island remain disorganized. Environmental conditions are conducive for development, and there is a high chance a tropical depression may form over the weekend as the center of the low pressure moves west-northwest to about 210 nm to the southwest of Clarion by late Sun. Regardless of tropical cyclone development, strong to near-gale force SE winds along with rough seas are expected near and to the southwest of Clarion Island through Mon. Elsewhere, 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. ...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 17.1N 127.4W at 2 AM PDT, and is moving west-northwest at 8 kt. Maximum sustained winds are 50 kt with gusts to 60 kt, and the minimum central pressure is 999 mb. Norbert will move to 17.4N 128.8W this afternoon, 17.8N 130.6W Sun morning, 18.1N 132.6W Sun afternoon, 18.4N 134.7W Mon morning, 18.4N 137.0W Mon afternoon, and 18.3N 139.4W Tue morning. Norbert will change little in intensity as it moves to the west of 140W early 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.