000 AXPZ20 KNHC 050925 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Dec 5 2023 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 FEATURE... Gulf of Tehuantepec Gale Warning: Strong high pressure over central Mexico is supporting a surge of northerly gap winds reaching gale force across the Gulf of Tehuantepec. An overnight scatterometer satellite pass indicated a plume of near-gale to gale force winds in the Gulf of Tehuantepec. This pattern will persist through mid week, with gales pulsing mainly at night into Thu. Seas may reach 10 to 12 ft downstream of the strongest winds during the overnight hours. Please read the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 05N100W to 07N108W, and from 09N110W to 06N125W. The ITCZ continues from 06N125W to 08N135W to beyond 06N140W. Scattered moderate convection is noted from 06N to 08N between 95W and 98W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more information on the gale warning in the Gulf of Tehuantepec. A broad ridge extends across the offshore waters of Baja California from 1025 mb high pressure near 32N128W to the Revillagigedo Islands. The pattern is supporting mainly moderate NW to N winds off Baja California and moderate to locally fresh NW winds over the Gulf of California. NW swell has moved across the Baja California Norte waters bringing 8 to 10 ft seas mainly over the waters beyond 60 nm, north of Cabo San Lazaro. Farther south, light breezes persist off southern Mexico with 4 to 7 ft combined seas in mixed swell. For the forecast, outside of the gap wind event in the Gulf of Tehuantepec, long- period NW swell will persist off Baja California and the Revillagigedo Islands through most of the week. Seas as high as 12 ft could move across the California Norte waters by Wed night. Reinforcing NW swell will arrive off Baja California Norte by Thu night into Fri, accompanying a cold front moving into the region. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E winds are prevailing across the Gulf of Papagayo. Seas are 5 to 6 ft in this area. Gentle to moderate winds are noted elsewhere, with 4 to 6 ft seas primarily in SW swell. Scattered thunderstorms are noted south of the monsoon trough off the coast of Colombia. For the forecast, high pressure building north of the region will support pulsing strong winds across the Gulf of Papagayo particularly at night. Seas will build well offshore of Guatemala by Wed due to swell generated by gale- force gap winds in the nearby Gulf of Tehuantepec. Gentle to moderate winds are forecast elsewhere. Moderate combined seas will persist through mid week in a mix of SW and NW swell. ...REMAINDER OF THE AREA... High pressure dominates the waters north of 20N. Recent scatterometer satellite passes confirmed fresh to strong trade winds persist south of the ridge, mainly from 10N to 22N west of 110W. Seas in this region are 9 to 13 ft, in a mix of locally seas due to the trade wind flow, and longer- period NW swell. An altimeter satellite pass showed 11 ft seas near 30N140W. This is the start of a new group of NW swell approaching the region from the north-central Pacific. Combined seas of 6 to 9 ft cover much of the region elsewhere west of 110W, although with primarily S to SE swell south of 10N. Gentle to moderate winds and 5 to 7 ft seas are noted east of 110W. A trough extends along roughly 110W between 07N and 19N, associated with an upper trough to its northwest. Scattered moderate convection persists from 11N to 14N between 108W and 112W. For the forecast, the high pressure will dissipate into Wed as a weak cold front moves eastward across the waters north of 25N through Thu. This will allow trade winds to diminish slightly west of 110W through mid week. Large, long- period NW swell accompanying the front will move across the waters north of 10N and west of 120W through mid week. This swell will bring seas as high as 16 ft north of 25N and west of 130W today. East of 110W, the combination of the NW swell with shorter- period NE swell emerging from gap wind events and fresh E trade winds will support rough seas from 07N to 12N between 95W and 110W from Thu into Fri. $$ Christensen