000
AXPZ20 KNHC 182128
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sat Jan 18 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURE...

Gulf of Tehuantepec Gale Warning: Strong high pressure will build
over northeastern Mexico and the western Gulf of Mexico late Sun
following the passage of cold front across the region. This
pattern will support strong to gale force gap winds across the
Tehuantepec Sun night into Mon, and subsequently rough to very 
rough seas downstream of the Gulf of Tehuantepec through Mon 
evening. These winds and seas will diminish through early Tue as 
the high pressure weakens and shifts eastward ahead of the next 
front moving into the northwest Gulf of Mexico. An even stronger 
area of high pressure will build over northeast Mexico and the 
western Gulf, supporting strong gales or even storm force winds 
across the Gulf of Tehuantepec through mid week, accompanied by a
broad area of rough to very rough seas downstream.

Climatologically, the first gale-force event of the season occurs
in mid-October, with the final gale-force event occurring in 
late March or early April. Occasionally, gale-force events may 
occur as early as September, and as late as May. The monthly 
distribution of Tehuantepec events shows that the largest number 
of gale force events occurs in December. Storm-force events occur
most often in January. 

Please refer to the latest NWS High Seas Forecast issued by the 
National Hurricane Center at the website: 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml, for more details.

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

The monsoon trough extends from southern Costa Rica near 09N83W 
to 05N91W. The ITCZ continues from 05N91W to 04N110W to 08N130W
to beyond 06N140W. Scattered moderate convection is noted from 
07N to 10N between 122W and 133W.

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

A ridge extends SE from 1027 mb high pressure located near 
33N134W to beyond Cabo Corrientes. This pattern is supporting 
moderate to locally fresh NW to N winds across the offshore 
waters of Baja California. Seas are 4 to 6 ft within these winds.
Light and variable winds are noted across the north and central 
parts of the Gulf of California, while gentle to moderate NW 
winds dominate the remainder of the Gulf. Seas are of 1 to 3 ft.
Moderate to fresh NW winds and seas of 5 to 7 ft are seen across
the offshore waters of Jalisco and Colima. Gentle to moderate W 
to NW winds prevail across the remainder of the Mexican offshore 
waters where seas are in the 3 to 5 ft range.

For the forecast, the main forecast issue will be a pair of 
successive cold fronts moving through the western Gulf of Mexico 
and southern Mexico, supporting gale force gap winds across the 
Gulf of Tehuantepec Sun night, with strong gales possible Tue 
night through mid week. This pattern will also support rough to 
very rough seas downstream of the Gulf of Tehuantepec off eastern
Oaxaca and Chiapas. The situation will be monitored over the 
next few days, and a Storm Warning may be required for mid week. 
Elsewhere, a ridge will continue to dominate the offshore waters 
of Baja California this weekend producing mainly gentle to 
moderate winds with moderate seas. Long period NW swell will 
reach the waters north of Punta Eugenia Sun night into early Mon 
morning building seas to 8 ft there. In the Gulf of California, 
expect fresh to locally strong NW winds Mon night through at
least Wed as strong high pressure settles over the Great Basin 
of the United States. Winds may reach minimal gale force over
the northern part of the Gulf by Tue morning. Gentle to moderate
winds and slight to moderate seas will persist elsewhere through
early next week. 

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

A recent scatterometer satellite pass indicated moderate NE across
the Gulf of Papagayo. Gentle to moderate N winds are in the Gulf
of Panama and downstream of the Azuero Peninsula to about 05N.
Similar wind speeds from the S are in the offshore waters of
Ecuador. Seas are 2 to 4 ft, except to 6 ft over the Gulf of 
Papagayo.

For the forecast, fresh to strong winds and moderate seas will 
prevail in the Papagayo region tonight and again on Mon. The 
next gap wind event is forecast in the Papagayo area by Wed night
as a strong high pressure builds north of area. Light to gentle 
winds and slight to moderate seas will prevail elsewhere. Seas 
generated by strong gale force winds in the Tehuantepec area will
propagate across the offshore waters of Guatemala and El Salvador
Mon and Mon night, then again Wed and Wed night. 

...REMAINDER OF THE AREA...

A 1027 mb high pressure is centered north of area near 33N134W. 
Its associated ridge dominates most of the waters north of the 
ITCZ and west of 110W. The pressure gradient between the high
pressure and lower pressure in the vicinity of the ITCZ is 
supporting fresh to strong NE winds and 8 to 11 ft from 09N to 
16N between 115W and 135W. Satellite derived wind data captured 
these winds. In addition, the pressure gradient between the 
ridge and a low pressure system located W of forecast region is 
producing an area of fresh to strong SE winds N of 20N and W of 
135W with seas of 8 to 9 ft. Gentle to moderate winds and 
moderate seas persist elsewhere.

For the forecast, the area of fresh to strong trade winds and 
rough seas around the southern periphery of the ridge will 
persist over the next 24 to 48 hours. The pressure gradient 
between the high pressure and the surface trough approaching from
the west will continue to bring fresh to strong E to SE winds 
and rough seas mainly across the waters N of 20N and W of 135W 
over the next couple of days. Another set of long period NW 
swell has reached the NW corner of the forecast area. This swell
event will propagate most of the waters W of 120W on Sun.

$$
GR