110 
AXPZ20 KNHC 281519
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sun Dec 28 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: Strong high pressure over 
the southern United States and eastern Mexico in the wake of an 
upcoming Gulf of America cold front will result in a tight 
pressure gradient. This will induce gale-force winds north winds
into the Gulf of Tehuantepec region beginning on Mon night. 
These winds may peak to 45 kt going into the middle part of the 
week. Brief gusts to storm force cannot be ruled out Tue night. 
Seas with these winds are expected to rapidly build to the range 
of 11 to 18 ft. Mariners transiting through the Gulf of 
Tehuantepec during this time are urged to take the necessary 
action to avoid the hazardous marine conditions that will be 
impacting these waters. Conditions in the Tehuantepec region are 
forecast to begin to improve early on Thu.

Developing Low Pressure/large swell: A surface trough analyzed 
from near 20N124W to 11N129W. This trough is paired with a 
vigorous and broad upper-level trough that is digging southward 
producing a large area of scattered to numerous showers and 
thunderstorms from 12N to 28N between 112W and 132W. This area is
also merging with a large NW swell that has been spreading across
the basin, with rough to very rough seas noted N of 18N and W of
112W. An overnight scatterometer satellite data pass indicated 
that strong to near gale-force winds are occurring with the 
strongest convection. Global models suggest that a low pressure 
will develop in association with this trough across the waters 
south of about 22N between 120W and 128W today into early next 
week. The interaction between this feature and strong high 
pressure building into the region is expected to result in a 
rather broad zone of increasing winds reaching to strong speeds 
roughly from 16N to 26.5N and west of the Revillagigedo Islands, 
accompanied by numerous areas of moderate to heavy rain along 
with embedded scattered showers and isolated thunderstorms. There
is a possibility that these winds may attain gale-force speeds, 
especially in the showers and thunderstorms. Rough to very rough 
seas will spread over much of the basin north of 10N and west of 
115W. Seas may reach up to 15 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 08N85W to 08N100W, where it 
transitions to the ITCZ to 10N123W to 10N140W. Scattered 
moderate convection is noted N of 08N between 112W and 132W.  
This area is also associated with a surface trough, analyzed 
from 20N124W to 11N129W. 

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

Please refer to the Special Features section for details on 
a gale warning that is in effect for the Gulf of Tehuantepec.

Strong high pressure of 1033 mb is located well north of the 
area near 43N131W. A ridge axis extends from the high southward 
to near 20N and west of the Revillagigedo Islands. Its related 
gradient is allowing for fresh north to northeast winds to exist 
across the offshore waters of Baja California. A decaying 
northwest swell is providing for rough seas offshore Baja 
California, except for moderate seas south of Cabo San Lucas. 
Moderate to fresh northwest winds and slight to moderate seas 
are found in the Gulf of California, while moderate north winds
and moderate seas are in the Gulf of 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 gradually subside 
through early Mon. Fresh to strong northwest winds are expected 
to develop in the Gulf of California tonight and continue into 
Tue night as high pressure strengthens across the region. Gentle 
to moderate north winds in the Gulf of Tehuantepec region will 
become fresh north winds early on Mon. A strong cold front will 
move across the Gulf of America Mon into Tue. High pressure 
building in behind the front will support the next gap wind event
in the Gulf of Tehuantepec.

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

High pressure centered over the eastern Gulf of America has an 
associated broad ridge that stretches southwestward toward
Central America. The gradient between the ridge and lower 
pressure to its south is allowing for fresh to strong northeast 
to east winds to exits in the Gulf of Papagayo region along with 
moderate seas. Weak low pressure off Colombia is producing 
scattered showers and thunderstorms south of the Gulf of Panama 
from 05N to 07.5N between the coast of Colombia and 80W. 
Elsewhere, moderate or weaker winds and moderate seas prevail.

For the forecast, the aforementioned high pressure will
continue to support pulsing fresh to strong easterly trade 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. 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 low 
pres/significant swell over the waters central portion of the 
area.

Broad surface ridging associated to strong high pressure that is
centered well north of the area reaches southward into the area 
to near 20N. A trough is analyzed from 20N124W to 11N129W. The 
gradient between the ridge and lower pressure in the tropics is 
allowing for moderate to fresh trade winds north of about 10N and
west of 120W. 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 18N125W. The tight pressure 
gradient between the subtropical ridge and the low pressure will 
sustain a large area of strong to near gale-force winds and 
rough to very rough seas, across most of the forecast waters 
north of about 15N and west of 117W into the early part of
the week. Winds may reach gales at times, more likely in 
scattered showers and thunderstorm, but with some possibility 
of winds become sustained at gale-force speeds in the tight
gradient north of the low. Conditions are forecast to improve
by the middle of the week. A cold front will move across the NW 
waters late next week, followed by fresh to strong NW winds and 
rough to very rough seas.

$$
ERA