Eastern Pacific Tropical Weather Discussion
370 AXPZ20 KNHC 150843 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Tropical Depression Fifteen-E is centered near 16.1N 122.6W at 15/0900 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. Ongoing shear and entrainment of dry air over the next several days will prevent this system from developing into a tropical storm. However, strong to near- gale force winds and rough to very rough seas will accompany Fifteen-E mainly on the north side of the low pressure as it continues to move westward over the next two to three 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 Fifteen-E NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gulf of Tehuantepec Gale Warning: High pressure building over southern Mexico will support strong to near-gale force N to NE gap winds across the Gulf of Tehuantepec into Wed, and will reach minimal gale force Wed night. Rough seas will accompany these gap winds. ...TROPICAL WAVES... A tropical wave is along 104W from 04N to 13N, moving west at 15 kt. Scattered moderate convection is from 11N to 15N between 100W and 105W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 08N90W to 10N105W to 06N120W, and from 13N120W to 12N140W. Scattered moderate convection is active from 04N to 12N between 80W and 100W, and from 10N to 15N between 125W and 130W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Numerous showers and thunderstorms are active off the coast of El Salvador beyond 90 nm. Scattered showers and thunderstorms are also active off Guerrero in southwest Mexico. Farther north, N swell along with fresh N winds are supporting combined seas to 8 ft west of Guadalupe Island. 1002 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, please see the Special Features section for information about the gale warning in the Gulf of Tehuantepec. Elsewhere, fresh SE to S winds pulse across the northern Gulf of California through Wed. Large N swell off Baja California Norte near Guadalupe Island will subside through mid 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, a ridge north of the area will continue to support pulsing fresh to occasionally strong easterly winds and moderate to rough seas across the Papagayo region through mid week, then pulsing to moderate to fresh thereafter. Moderate winds and seas will prevail elsewhere. ...REMAINDER OF THE AREA... Please see the Special Features section for more information about Tropical Depression Fifteen-E. The center of Tropical Depression Norbert is centered west of the discussion area near 20.3N 141.7W at 15/0900 UTC, moving west at 12 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered showers and thunderstorms, along with fresh to strong E winds and 8-10 ft seas are active northeast of the center, reaching from 21N to 23N between 137W and 140W. Please read the latest CPHC Public Advisory at https://www.nhc.noaa.gov/text/HFOTCPCP1.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/HFOTCMCP1.shtml for more details. Elsewhere, N swell to 8 ft is impacting the waters north of 29N between 120w and 125W. SW swell from the southern hemisphere is cross the equator and reaching as far north as 04N between 95W and 120W. Gentle to moderate winds and 4-6 ft combined seas in mixed swell are noted elsewhere. For the forecast, winds and seas following Norbert will diminish through late today east of 140W. Fifteen-E will move to 15.8N 124.0W this afternoon, 15.5N 126.0W Wed morning, 15.4N 128.0W Wed afternoon, 15.5N 130.0W Thu morning, become a remnant low and move to 15.5N 132.4W Thu afternoon, and 15.6N 134.8W Fri morning. Fifteen-E will change little in intensity as it moves to 16.3N 139.0W early Sat. Fresh to strong winds and moderate to rough seas on the northern envelop of Fifteen-E will cover the area from 15N to 25N east of 120W through Fri. The southerly swell to 8 ft south of 04N will subside through late today, as will the northerly swell north of 29N between 120W and 125W.