000 AXPZ20 KNHC 060255 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Dec 6 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec Gale Warning: Strong high pressure stretches over central Mexico, supporting northerly gale force winds across the Gulf of Tehuantepec. This pattern will persist through Thu. Seas expected to reach 8-11 ft through this period, peaking to 12 ft on Thu morning. Seas are expected to completely subside below 8 ft by Fri. 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 the coast of Panama/Colombia near 08N78W to 06N103W. The ITCZ extends from 06N103W to beyond 08N140W. Scattered moderate convection is noted from 03N to 11N between 98W and 131W. ...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 31N127W to Cabo San Lucas, Mexico. The pattern is supporting gentle northerly winds across most of the Baja California offshore waters with moderate winds across Baja California Sur offshore waters. Moderate to fresh N to NW winds prevail over the Gulf of California. NW swell across the Baja California Norte waters is bringing 8 to 10 ft seas mainly over the waters beyond 60 nm north of Cabo San Lazaro. Seas range 3 to 4 ft across the Gulf of California. Farther south, gentle to moderate breezes persist off southern Mexico with 4 to 6 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 Sat. Seas as high as 12 ft could move across the Baja California Norte waters by Wed into Wed night. Reinforcing NW swell will arrive off Baja California Norte by Thu night into Fri, accompanying a cold front moving into the region. Swells will subside later in the weekend. Strong winds could develop across most of the Gulf of California this weekend, producing rough seas. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to strong NE to E winds prevailing across the Gulf of Papagayo. Seas are 5 to 7 ft in this area. An earlier scatterometer pass confirmed gentle to moderate winds elsewhere over the region. Seas range 5 to 7 ft in the Guatemala and El Salvador offshore waters mostly within N to NW swell due to the influence of the Gulf of Tehuantepec gap wind event. Elsewhere, seas range 4 to 6 ft seas primarily in S to SW swell. Scattered thunderstorms are noted south of the monsoon trough off the coast of Colombia. For the forecast, high pressure north of the region will support pulsing strong winds across the Gulf of Papagayo particularly at night through the rest of the week. Seas will build well offshore of Guatemala by Wed into Thu due to swell generated by gale-force gap winds in the Gulf of Tehuantepec. Gentle to moderate winds are forecast elsewhere. Moderate combined seas will persist through the rest of the week in a mix of SW and NW swell. ...REMAINDER OF THE AREA... High pressure dominates the waters north of 20N. Fresh to strong trade winds persist south of the ridge, mainly 07N to 23N west of 115W. Seas in this region are 8 to 12 ft, in a mix of seas due to the trade wind flow, and long-period NW swell. A cold front stretches NW of the area with moderate to fresh SW winds ahead of it. A large reinforcing NW swell is beginning to move into the area, bringing 12 to 16 ft seas N of 24N and W of 133W. Combined seas of 8 to 10 ft cover much of the region elsewhere west of 115W, although with primarily S to SE swell south of 05N. Gentle to moderate winds and 4 to 7 ft seas are noted east of 115W. A sfc trough extends along roughly 119W between 10N and 16N, associated with an upper trough to its northwest. 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 115W through mid week. Large, long-period NW swell accompanying the front will move across the waters north of 10N and west of 120W through Wed into Thu. This swell will bring seas as high as 16 ft north of 25N and west of 130W tonight. 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. $$ ERA