Eastern Pacific Tropical Weather Discussion
576 AXPZ20 KNHC 140358 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Mon Sep 14 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 19.2N 135.3W at 14/0300 UTC, moving west-northwest at 12 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas are up to 17 ft, or 5 m. The center is partially exposed, with numerous moderate to scattered strong convection is noted within 90 nm in the NE quadrant of Norbert, with scattered moderate convection within 120 nm SE quadrant. Norbert is expected to move west-northwestward to westward during the next few days. While some fluctuations in intensity remain possible in the next 12 h or so, Norbert is forecast to begin a weakening trend that should persist through the forecast period. Tropical Depression Fifteen-E is centered near 17.0N 118.3W at 14/0300 UTC, moving west at 9 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are 8 to 11 ft. Numerous moderate to scattered strong convection is noted within 90 nm in the SE quadrant, with scattered moderate convection extending out to 240 nm elsewhere in the southeast semicircle. The depression on a mainly westward track with a slightly increase in forward speed for the next during the couple of days. Only slight short-term strengthening is called for and the system is expected to begin weakening in a day or so, with the cyclone degenerating into a remnant low in 96 hours or sooner. 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 Norbert and Fifteen-E NHC Forecast/Advisories and Public Advisories at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is along 100W from 05N to 13N, moving west at 15-20 kt. Associated convection is described below in the ITCZ/Monsoon Trough section. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 06N100W to 08N115W. Scattered moderate to isolated strong convection is active from 05N to 11N between 85W and 105W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more information about Tropical Depression Fifteen-E. Divergent flow aloft north of an upper low is supporting a line of showers and thunderstorms from 15N105W to across the Mexican coast of Nayarit. Fresh N gap winds are across the Gulf of Tehuantepec. Elsewhere, gentle to moderate breezes and 3-5 ft seas prevail across Mexican offshore waters, with 1-3 ft seas in the Gulf of California. For the forecast, a ridge will build across the offshore waters of Baja California, bringing moderate to locally fresh NW to N winds through the early part of the week. Expect fresh winds across the northern Gulf of California through the early part of the week due to the pressure gradient between the ridge and lower pressure over the Colorado River valley, locally strong Mon night. Winds will freshen again off Baja California by the end of the week, locally strong near Punta Eugenia. Looking ahead, expect strong to near- gale N gap winds and rough seas across the Tehuantepec by the middle of the 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 locally rough seas across the Gulf of Papagayo region, extending downstream to near 90W. Elsewhere, moderate or weaker winds and moderate seas are prevalent, except slight seas offshore Colombia and western Panama. Convection continues to develop on either side of the monsoon trough. Gusty winds and higher seas are likely occurring near thunderstorms. For the forecast, the 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 Thu, then pulsing to moderate to fresh thereafter. Moderate to locally fresh N winds may pulse in the Gulf of Panama at night into early Thu. Winds will be moderate or weaker elsewhere along with moderate seas, except locally rough southwest of the Galapagos Islands through Mon, and slight offshore Colombia and eastern Panama. ...REMAINDER OF THE AREA... Please see the Special Features section for more information about Tropical Storm Norbert and Tropical Depression Fifteen-E. Away from the impacts of T.S. Norbert and T.D. Fifteen-E, mainly moderate to fresh winds cover the waters north of 15N and west of 115W. Moderate to fresh SE-S winds and rough seas are found south of 05N between 95W and 130W. Winds are moderate or weaker elsewhere with moderate seas. For the forecast, Norbert will move to 19.5N 137.2W Mon morning, 20.0N 139.8W Mon evening, then move west of the area to 20.4N 142.5W Tue morning. Norbert will weaken to a remnant low near 20.6N 145.2W Tue evening, and dissipate Wed morning. Meanwhile, Fifteen-E will strengthen to a tropical storm near 16.8N 119.6W Mon morning, move to 16.5N 121.4W Mon evening, 16.3N 123.4W Tue morning, weaken to a tropical depression near 16.0N 125.8W Tue evening, 15.7N 128.3W Wed morning, and 15.4N 130.8W Wed evening. Fifteen-E will become a remnant low as it moves to 15.5N 135.5W late Thu. Elsewhere, a cross equatorial swell will persist over the next several days producing seas to 9 ft south of 05N. A tight pressure gradient will result in locally fresh N winds and rough seas in the north of 22N and east of 125W through the early part of the week.