000
AXPZ20 KNHC 290424
TWDEP 

Tropical Weather Discussion...CORRECTED
NWS National Hurricane Center Miami FL
0405 UTC Mon Dec 29 2025

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 0000 UTC surface analysis and satellite imagery through
0300 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: The next gap wind event across
the Tehunatepec region is expected Mon afternoon as a ridge builds
across the eastern slopes of the Sierra Madre Mountains in Mexico, 
behind a cold front moving across the Gulf of America. Wind are 
forecast to suddenly increase to 35 to 40 kt, with seas building to 
9 to 12 ft by Mon night. Fresh to strong winds and large seas 
generated by this event will spread well away from the Tehuantepec 
area, with seas 8 ft or greater reaching as far west as 105W by Tue 
evening. Marine interests transiting across or in the Gulf of 
Tehuantepec Tue morning through Tue night should be aware of this 
upcoming gap wind event, and take the necessary action to avoid this 
hazardous marine conditions over the affected waters. Gale 
conditions are forecast to continue through Wed. Conditions in the 
Tehuantepec region are forecast to begin to improve early on Thu.

Developing Low Pressure/Swell event: A surface trough is analyzed
from 23N120W to 12N127W. This trough is paired with a vigorous 
and broad upper-level trough that is digging southward producing 
a large area of scattered showers and thunderstorms from 13N to 
20N between 116W and 130W. This area is also merging with a large
NW to N swell that has been spreading across the basin, with 
rough seas noted from 07N to 27N W of 120W, and from 14N to 25N 
between 112W and 120W. Latest scatterometer satellite data pass 
indicated that strong to near gale-force winds are occurring with
the strongest convection. Global models continue to suggest that
a low pressure will develop in association with this trough on 
Mon near 20N122W. The interaction between this feature and strong
high pressure building into the region is expected to result in 
a broad zone of fresh to strong winds from 16N to 26N and west of
118W. There is a possibility that these winds may attain gale- 
force speeds, especially in the showers and thunderstorms. Rough 
seas will spread over much of the basin north of 10N and west of 
115W. Seas may reach up to 14 ft with the strongest winds. 
Conditions are forecast to improve by the middle of the week.

Please read the latest High Seas Forecast issued by the National
Hurricane Center at website:
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more information.

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

The monsoon trough extends from 10N85W to 08N105W. The ITCZ
continues from 10N85W to 10N125W to 07N140W. Scattered moderate 
convection is noted from 07N to 11N between 115W and 122W. 

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

A Gale Warning is in effect for the Gulf of Tehuantepec. Please 
refer to the Special Features section for more details. 

High pressure of 1031 mb is located well north of the area near 
39N132W. A ridge axis extends from the high across the offshore
forecast waters of Baja California. Its associated pressure 
gradient is allowing for fresh north to northeast winds to exist 
across the offshore waters of Baja California with moderate seas.
Moderate to fresh northwest winds and slight to moderate seas 
are found in the Gulf of California, while light winds and slight
seas are in the Tehuantepec region. Elsewhere, moderate or weaker
winds and slight to moderate seas prevail.

For the forecast, NW swell propagating through the offshore waters
of the Baja California peninsula will continue to subside through
early Mon. Fresh to strong northwest winds and building seas are
expected to persist across most of the Gulf of California through
Tue night as high pressure persists over the SW of the United
States. Expect increasing winds and building seas in the Gulf of 
Tehuantepec by Mon afternoon. Winds are forecast to reach 30 to
40 kt with seas of up to 16 or 17 ft. 

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

High pressure N of the area supports fresh to strong northeast 
to east winds in the Gulf of Papagayo with moderate seas. Weak 
low pressure of 1009 mb off Colombia is producing scattered 
showers and thunderstorms in the eastern Gulf of Panama. 
Elsewhere, moderate or weaker winds and moderate seas prevail.

For the forecast, the aforementioned high pressure will continue
to support pulsing fresh to strong NE to E winds in the Gulf of 
Papagayo through the forecast period. Gentle to moderate northerly
winds are expected in the Gulf of Panama through the period, pulsing 
to fresh at night at times. Seas generated in the Tehuantepec region 
will propagate across the offshore forecast waters of Guatemala and 
El Salvador Tue through Wed night. Gentle or lighter winds and 
slight to moderate seas are expected elsewhere through the period.

...REMAINDER OF THE AREA...

Please read the Special Features section for details on a developing
low pres and a significant swell event over the central waters of
the forecast region. 

Broad surface ridge associated to a 1031 mb high pressure located
near 39N132W dominates the area N of 20N and W of 110W. The
pressure gradient between the high and the above mentioned surface
trough is allowing for a large area of fresh to strong NE winds
from 17N to 27N W of 120W. Seas of 8 to 11 ft are noted within
these winds based on altimeter data. Elsewhere, moderate or weaker
winds and moderate seas are prevalent.

For the forecast, the slowly decaying northwest swell is forecast
to maintain that trend through early Mon as high pressure builds
into the regional waters. The aforementioned trough will serve 
as the seedling for the development of a broad low today, perhaps
near 20N122W. A cold front will move across the NW waters late 
this week, followed by fresh to strong NW winds and rough to very
rough seas.

$$
GR