000 AXPZ20 KNHC 210337 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu Nov 21 2024 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 0330 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A gap wind event is developing in the Gulf of Tehuantepec as high pressure builds over central Mexico in the wake of a strong cold front moving through far southern Mexico. Strong N winds are ongoing in the Gulf of Tehuantepec, and gale force winds will develop later this evening. Strong gales will be possible late tonight through Thu night. Rough seas will occur across the Gulf of Tehuantepec this evening through this weekend, with very rough seas likely in the area of strongest wind. Seas will peak around 17 ft on Thu. Gale force winds will end Sat morning with strong winds ending by early Sun morning. Seas will fall below 12 ft Fri afternoon and below 8 ft by Sat night. For more details, please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https//www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 16N93W to a 1011 mb low near 15N101W to a 1010 mb low near 09N124W to 08N127W. The ITCZ continues from 08N127W to beyond 08N140W. Scattered moderate convection is occurring from 08N to 12N between 117W and 133W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section for information on the developing Gulf of Tehuantepec Gale event. A 1022 mb high is centered near 31N122W and ridging extends across the Baja California offshore waters. This pattern supports gentle to moderate N to NE winds across the Baja California offshore waters and points farther south off the coast of southwestern Mexico. A residual N to NW swell is promoting seas of 8 to 9 ft north of 20.5N and west of 114.5W. Elsewhere, the tight pressure gradient between the ridge and a trough in northwestern Mexico is supporting fresh to locally strong NW winds in the Gulf of California, including the waters surrounding Cabo San Lucas. Seas are 3 to 6 ft in this region. For the forecast, gale force winds will develop in the Gulf of Tehuantepec this evening and continue into Sat morning. Strong gales will be possible late tonight through Thu night. Rough seas will occur across the Gulf of Tehuantepec this evening through this weekend, with very rough seas likely in the area of strongest wind. These gales and rough seas will reach beyond 300 NM downstream of the Gulf of Tehuantepec into early Sat. Elsewhere, fresh to locally strong NW winds will continue to pulse in the Gulf of California into early Fri. Rough seas off the coast of Baja California will subside overnight. Another long-period NW swell will reintroduce rough seas offshore of Baja California Norte on Thu before seas subside on Fri. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate SW winds are occurring offshore of Costa Rica southeastward through the coastal waters of Colombia, where seas of 4 to 6 ft are observed. Elsewhere, gentle to locally moderate W to SW winds and seas of 3 to 5 ft prevail across the remainder of the Central and South American offshore waters. For the forecast, fresh to strong N to NE winds and very rough seas associated with a Gulf of Tehuantepec gap wind event will impact the far western Guatemala offshore waters early Thu through Fri. Fresh to strong E to NE winds will then pulse in the Gulf of Papagayo Fri into Sun. Otherwise, moderate SE to SW winds will prevail across the offshore waters through this weekend. Looking ahead, rough seas in SW swell will reach the waters off the coast of Ecuador by early next week. ...REMAINDER OF THE AREA... A 1022 mb high is centered near 31N122W and ridging extends across the waters north of the monsoon trough. A tightening pressure gradient between the ridge and a cold front approaching 30N140W is supporting fresh to locally strong SW winds north of 27N and west of 128W. Moderate E to NE winds are occurring along the southern periphery of the ridge and west of 110W. Multiple sets of NW swell are promoting seas of 7 to 10 ft north of 15N, and pockets of 7 to 8 ft seas are noted along the monsoon trough, in a combination of NW and SW swell, along with shorter- period NE seas due to trade wind flow. South of the monsoon trough, gentle to moderate SE winds and seas of 5 to 7 ft prevail. For the forecast, the high pressure will persist and shift southward across the waters through this weekend. The cold front approaching 30N140W will lead to fresh to locally strong SW winds north of 28N and west of 127W into Fri morning before winds diminish. Rough seas along the monsoon trough and off the coast of Baja California will subside by late Thu. Another long- period NW swell will reinforce rough seas north of 26N tonight through Sat. Looking ahead, a complex wave pattern will develop by Sun over the tropical eastern Pacific from 05N to 10N between 105W and 115W in a mix of NW and SW swell, along with a component of shorter period NE swell generated by the Tehuantepec gap wind event. SW swell to 8 ft will overtake the region south of 10N and east of 115W Mon and Tue. $$ ADAMS