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Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Sep 15 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... Newly downgraded Tropical Depression Norbert is centered near 20.2N 140.5W at 15/0300 UTC, moving west-northwest at 13 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas about 13 ft. Norbert remains a heavily sheared storm, with a small area of scattered moderate convection between 120-150 nm in the NE quadrant of the center. Norbert is moving toward the westward and is expected to maintain this general motion during the next couple of days. Gradual weakening is forecast during the next 48 hours, and Norbert is expected to become a post- tropical remnant low tomorrow. Tropical Depression Fifteen-E is centered near 16.5N 121.6W at 15/0300 UTC, moving west at 9 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are 12 ft. The center of Fifteen-E remains exposed, but numerous moderate to isolated strong convection is noted within 60-240 nm in the southeast semicircle of the center. Fifteen-E has a compact and well-organized center, and is expected to intensify to a minimal tropical storm overnight. But it will struggle to maintain this intensity as it continues in a westward direction, and it is expected to start weakening in a couple of days. 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 103W from 04N to 13N, moving west at 15 kt. Scattered moderate convection is from 05N to 12N between 100W and 105W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 07N115W to 14N130W to beyond 12N140W. Scattered moderate convection is active from 05N to 11N between 80W and 90W, and from 03N to 07N between 115W and 120W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Numerous showers and thunderstorms are active near the Gulf of Fonseca and the coast of El Salvador. Scattered showers and thunderstorms are also active off western Oaxaca and eastern Guerrero in southwest Mexico. Farther north, N swell along with fresh N winds are supporting combined seas to 8 ft west of Guadalupe Island. 1000 mb low pressure over the Colorado River valley is supporting fresh SE winds across the northern Gulf of California. Fresh to strong N to NE gap winds are starting over the northern Gulf of Tehuantepec, following a tropical wave passing to the west farther south. Fresh E to SE winds are likely off Guerrero beyond 90 nm following the tropical wave. Gentle to moderate winds and 3-5 ft are noted elsewhere, except 1-3 ft in the central and southern Gulf. 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. Winds will freshen again off Baja California by the end of the week, locally strong near Punta Eugenia. 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 with moderate seas across the Gulf of Papagayo region, extending downstream to near 90W. Moderate to fresh winds from this gap wind extends to the outer offshore waters of El Salvador and Guatemala. 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, 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 Depression Norbert and Tropical Depression Fifteen-E. Away from the impacts of T.D. 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 02N to the W of the Galapagos to 115W. Winds are moderate or weaker elsewhere with moderate seas. For the forecast, Norbert will continue to weaken as the center moves west of 140W overnight. Strong winds and rough seas will follow Norbert west of 135W from 18N to 28N through Tue. Fifteen-E will strengthen to a tropical storm near 16.7N 121.8W Tue morning, move to 16.6N 123.7W Tue afternoon, 16.4N 125.4W Wed morning, 16.4N 127.3W Wed afternoon, 16.6N 129.7W Thu morning, and weaken to a remnant low near 16.9N 132.1W Thu afternoon. Fifteen-E will change little in intensity as it moves near 17.5N 136.4W Fri afternoon.