AXPZ20 KNHC 060915

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 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 0600 UTC surface analysis and satellite imagery through 0900 UTC.


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.


The monsoon trough extends from 09N84W to 06N102W. The ITCZ extends from 06N102W to 11N116W, then resumes W of a trough along 120W near 08N120W to beyond 08N140W. Scattered moderate convection is noted from 05N to 16N between 104W and 134W.


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 1022 mb high pressure near 30N127W to Cabo San Lazaro, 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 9 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 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.


Fresh to strong NE to E winds prevailing across the Gulf of Papagayo, where seas are near 5 to 7 ft. An earlier scatterometer pass confirmed these winds, and 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 W 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.


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 in the NW corner of the basin from 31N135W to 27N140W with moderate to fresh winds in its vicinity. A large reinforcing NW swell is bringing 12 to 16 ft seas N of 23N and W of 130W. 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 sfc trough is analyzed along 120W between 10N and 15N with scattered moderate convection.

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.

$$ ERA