000
AXPZ20 KNHC 211548
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Thu Dec 21 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
1500 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: High pressure over the W Gulf 
of Mexico along with lower pressures over the tropical E Pacific 
are forcing a N gap wind event over the Gulf of Tehuantepec. Gale
conditions will continue over the Gulf of Tehuantepec today. Peak
seas are near 13 ft. Strong to near-gale force N winds will then
occur there before diminishing Sat. 

Eastern Pacific Significant Swell event: Very large NW swell 
with seas of 12-16 ft are continuing to impact the waters north 
of 26N between 122W-136W. An 0600 UTC altimeter pass verified 
the occurrence of these seas along 130W. As the swell continues 
to propagate southeastward, seas will subside below 12 ft by 
early Fri morning.

Please read the latest NWS 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 Colombia near 07N78W
to 05N90W. The ITCZ extends from 05N90W to beyond 06N140W. 
Scattered moderate and isolated strong convection is noted from 
04N-08N between 102-117W, and from 03N-08N west of 130W. 

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see the Special Features section for details on the 
ongoing Gulf of Tehuantepec Gale Warning. 

Aside from the gale in the Gulf of Tehuantepec, a weak pressure 
gradient prevails across the area with moderate or less winds
occurring. Seas are 5-7 ft in the Pacific waters, except for 
waters west of Baja California Norte where seas are 7-9 ft in NW 
swell. Seas in the Gulf of California are 1-2 ft.

For the forecast, a cold front is moving over the waters west of
Baja California today ahead of a low pressure that will approach
Baja California Norte from the west on Fri bringing fresh to 
strong W to NW winds. Elsewhere, winds across the area will be 
moderate or weaker. Large NW swell will propagate southeastward 
across the waters west of Baja California today and Fri before 
diminishing Sat. Looking ahead, another set of NW swell will move
into the Baja California Norte waters Sun and Mon. 

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

A high pressure ridge over Central America is forcing strong to 
near-gale force NE winds over the Gulf of Papagayo region. Seas
are 8-10 ft. Fresh to strong N winds are also occurring over the
Gulf of Panama with seas to 8 ft. Elsewhere, winds are moderate
or weaker. Large NW swell with seas to 8 ft in the Guatemala and
El Salvador offshore waters are being generated by a Gulf of 
Tehuantepec gale-force gap wind event. 

For the forecast, the strong to near-gale force NE winds over 
the Gulf of Papagayo will continue through tonight. Then, fresh 
to strong NE winds will prevail until diminishing on Sat. Fresh 
to strong N winds will continue over the Gulf of Panama before 
diminishing to moderate Fri. Elsewhere, winds are expected to be 
moderate or weaker for the next several days. Large NW swell 
generated by a Gulf of Tehuantepec gale-force gap wind event will
continue to impact the Guatemala and El Salvador offshore waters
through Fri night.

...REMAINDER OF THE AREA...

Please see the Special Features section above for details on a
significant swell event currently affecting the N portion of the
basin.

A cold front extends from 30N120W southwestward to 23N134W, where
it transitions to a dissipating cold front to 12N140W. Isolated
showers and thunderstorms are occurring north of 27N between
124W-128W. Winds are NW fresh to strong behind the front north of
28N and only moderate or weaker ahead of it. In addition to the
very large NW swell described above, NW swell of 8 ft or more are
occurring north of a line from 21N140W to 28N120W. For the
remainder of the waters, the NE trades are fresh 07N-10N west of
137W and from 05N-10N east of 103W with seas 8-11 ft. Elsewhere,
the trades are moderate or weaker with seas 5-7 ft.

For the forecast, the cold front and an accompanying low center
will progress eastward with NW winds north of 25N east of 125W
dropping below fresh on Fri night. Likewise, the NE trades will
weaken to moderate across the waters by Sat. The large NW swell
will continue propagating southeastward while gradually
diminishing. 8 ft or greater seas with the swell will reach from
10N140W to 13W117W Fri night. Elsewhere, seas will be 6-8 ft.

$$
Landsea