Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1530 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. Strong winds likely stretch as far south as 11N. This pattern will persist through Thu. Seas expected to reach 8-12 ft through this period, peaking to 12 ft on Wed night into Thu. Strong winds will diminish by by Fri along with seas subsiding below 8 ft. 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 Costa Rica near 09N84W to 06N104W. The ITCZ extends from 07N121W to beyond 06N140W. Scattered moderate convection is noted from 05n to 11N between 95W and 140W. ...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 weakening high pressure, which has a central pressure of 1022 mb near 29N129W. The pattern is supporting light to gentle northerly winds across most of the Baja California offshore waters. Moderate N to NW winds prevail over the Gulf of California, including the entrance of the Gulf. NW swell across the Baja California waters is bringing 8 to 9 ft seas mainly over the waters beyond 60 nm of the Baja California coastline. Seas range 3 to 4 ft across the Gulf of California. Farther south, light to gentle breezes persist off southern Mexico with 4 to 6 ft combined seas in mixed swell. For the forecast, outside of the gap winds 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 tonight. Reinforcing NW swell will arrive off Baja California Norte by Thu night into Fri, accompanying a decaying 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 prevail across the Gulf of Papagayo, where seas are near 5 to 7 ft. 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 showers and 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 at night through the rest of the week. Seas will build well offshore of Guatemala through 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 locally strong trade winds persist south of the ridge, mainly 07N to 23N west of 115W. Seas in this region are 8 to 14 ft, in a mix of seas due to the trade wind flow, and long-period NW swell. A cold front stretches in the NW corner of the basin from 31N132W to 27N140W with moderate to fresh N to NE winds behind the front. A large reinforcing NW swell is bringing 10 to 14 ft seas N of 12N and W of 125W. Combined seas of 8 to 10 ft cover much of the region elsewhere W of 115W, although with primarily S to SE swell S of 05N. Gentle to moderate winds and 4 to 7 ft seas are noted east of 115W. A surface trough is analyzed along 112W from 07N to 11N and along 118W from 08N to 12N with scattered moderate convection near them. For the forecast, the high pressure will dissipate today as the cold front continues its movement to the E across the waters N of 25N through Thu. This will allow for trade winds to diminish slightly W of 115W today. Large, long-period NW swell accompanying the front will continue to move across the waters N of 10N and W of 120W through Thu supporting seas to 16 ft today N of 20N and W of 130W. E of 115W, 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.