AXPZ20 KNHC 040246
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
Based on 0000 UTC surface analysis and satellite imagery through
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
...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.