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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 040246
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Fri Dec 4 2020

Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 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
0240 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: The pressure gradient between 
high pressure building behind a cold front moving across the 
western Gulf of Mexico and the eastern north Pacific monsoon
trough is generating gale force winds in the Gulf of Tehuantepec.
Gale force winds are expected through Fri night, and then again 
Sun night through Tue night. Seas are forecast to build to 15-17 
ft with this gap wind event by Tue. Please read the latest NWS 
High Seas Forecast issued by the National Hurricane Center at 
website https://www.nhc.noaa.gov/text/MIAHSFEP2.html for more 
details.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from 09N83W to 06N95W to 12N115W to 
09N128W. The ITCZ continues from 09N128W to beyond 09N140W. 
Scattered moderate convection is noted from 06N to 10N between 
83W and 96W, from 08N to 11N between 105W and 110W and from 10N 
to 12N between 115W and 140W. 

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

Winds have diminished below gale force over the northern Gulf of
California, wind near gale force winds prevailing over the
northern Gulf. Strong gusty NE winds are also funneling through 
the passes on the west side of the Baja California peninsula. 

A Gale warning is in effect for the Gulf of Tehuantepec. Please
see Special Features section for more details. NW swell will 
propagate across the waters N of Cabo San Lazaro tonight into Fri
morning building seas to 8-12 ft. This swell will reach the 
Revillagigedo Islands by late Fri with building seas to 8 ft.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and 
WITHIN 750 NM OF ECUADOR...

Fresh to locally strong NE to E winds are expected in the Gulf 
of Papagayo over the next couple of days, particularly during 
the overnight and early morning hours. Elsewhwere, light to 
gentle winds are expected north of the monsoon trough, with 
moderate to fresh S to SW winds south of the trough axis, through
the upcoming weekend. 

REMAINDER OF THE AREA...

High pressure of 1026 mb located near 33N127W dominates the 
northern forecast waters. The pressure gradient between the high 
and lower pressures in the vicinity of the ITCZ is supporting 
moderate to fresh trade winds roughly from 10N to 20N west of 
125W. Seas are 8 to 12 ft in NW swell across this area. A ridge
will persist across the northern forecast waters over the next
several days, keeping a large area of fresh trade winds. 

Large long period NW swell continues to propagate across most of
the waters N of the equator and W of 120W, with seas of 12 to 14
ft W of a line from 30N129W to 16N140W. Seas associated with 
this swell event will diminish tonight and Fri as the area of 
swell propagates to the east-southeast and decays. Another NW
swell event is forecast to reach the NW corner of the forecast
area by Sat.

$$
AL