436 
AXPZ20 KNHC 181545
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 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 1200 UTC surface analysis and satellite imagery through
1500 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 gap winds pulsing to gale force 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 02N100W. The ITCZ extends from 02N100W to 06N122W, and from 
07N130W to beyond 06N140W. Scattered moderate convection is 
noted from 07N to 11N between 111W and 113W, and from 06N to 08N
between 120W and 133W.

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

A ridge extends SE from 1028 mb high pressure located near 
33N134W to near 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. 
Gentle to locally moderate winds in the Gulf of California with
seas of 1 to 3 ft. Gentle to moderate W to NW winds dominate the
Mexican offshore waters S of Cabo Corrientes 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 pulses of 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 early Wed as strong high pressure settles over 
the Great Basin of the United States. Gentle to moderate winds 
and slight to moderate seas will persist elsewhere through at 
least Sun.

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

A recent scatterometer satellite pass indicated fresh to strong
gap winds across the Gulf of Papagayo. Gentle breezes are noted 
elsewhere over offshore waters from Ecuador to Guatemala. 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 through tonight. 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 1028 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. A surface trough is analyzed along the 
ITCZ near 125W. This pattern is supporting fresh to strong NE 
winds and 8 to 11 ft from 09N to 16N between 115W and 135W.
Gentle to moderate winds and moderate seas persist elsewhere. A 
few showers and thunderstorms are noted along the surface trough.

For the forecast, the surface trough along the ITCZ near 125W 
will move westward over the next couple of days. The area of 
fresh to strong winds and rough seas will move in tandem with 
this trough due to the pressure gradient between the trough and 
high pressure to the north. In addition, the pressure gradient 
between the high pressure and another surface trough approaching 
from the west will bring fresh to strong E to SE winds and 
building seas of 8 to 11 ft across the waters north of 24N and 
west of 137W by Sun. 

$$
GR