000
AXPZ20 KNHC 221546
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sun Dec 22 2024

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: The pressure gradient between 
persistent high pressure over eastern Mexico and low pressure 
within the eastern north Pacific monsoon trough will continue to 
support gale-force gap winds in the Gulf of Tehuantepec N of 14N
through tonight. Presently, strong N to NE winds extend beyond
the Gulf coast to near 300 nm offshore. Seas within and just 
downwind of the gale force winds at expected to peak 12 to 14 
ft. The high pressure will shift east by early Mon, with the 
pressure gradient loosening. This will diminish winds below gale 
force early Mon with fresh to strong northerly pulses thereafter 
into mid-week. Please see the latest NWS High Seas and Offshore 
Waters Forecasts issued by the National Hurricane Center at 
website:
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and 
www.nhc.noaa.gov/marine/offshores_eastpac.php for more 
details.

Significant NW swell: A large, complex, and powerful low 
pressure system north of the area will move NE through Mon,
followed by another similar low pressure system sweeping just
north of the area waters. These systems have generated several 
rounds of large NW swell that will propagate into the area 
through next week. This morning, seas greater than 12 ft cover 
the waters NW of a line from 30N119W to 15N130W to 09N140W, with 
seas peaking at 18-19 ft north of 28N between 125W and 134W. 
This large NW swell will continue to spread SE, covering the 
waters from west of Baja California near Punta Eugenia to 08N132W
early this evening, when a reinforcing pulse of new NW swell 
will enter the NW waters, with peak seas of 20-24 ft near 
30N140W. Please see the latest NWS High Seas Forecast issued by 
the National Hurricane Center at website:
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.

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

The monsoon trough extends from 11N73.5W to 09N84W to 05N92.5W 
to 06N104W. The ITCZ extends from 06N104W to 07.5N125W to beyond
07N140W. Scattered moderate isolated strong convection is noted 
from 03.5N to 09N east of 99W to the coast of Colombia.

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

Please read the Special Features Section for information on a 
Gale Warning in the Gulf of Tehuantepec, and significant NW 
swell that will impact the waters offshore Baja California 
through next week.

Aside from those conditions, a 1024 mb high pressure center is
located near 27N129W, with an associated ridge extending
southeastward to offshore of Cabo Corrientes. The pressure 
gradient between this area of high pressure and a trough over NW 
Mexico is supporting with moderate to locally fresh northerly 
winds across the Baja California waters, and inside the Gulf of
California, while gentle to moderate winds prevail south of 20N 
to offshore of Manzanillo. Seas are in the 5 to 7 ft over the 
open waters off Mexico, except are quickly building to 7 to 12 
ft well offshore Baja California. Seas are 2 to 4 ft over the 
Gulf of California, except 2 ft or less over the northern Gulf.

For the forecast, other than the aforementioned Gale Warning in 
the Tehuantepec region and significant NW swell, high pressure
will generally remain in place to the west of Baja California
through Tue, before a weakening cold front moves into the area
Tue night through Wed. Moderate northerly winds across the Baja
waters will pulse to fresh at times through Tue, then increase to  
fresh to strong from Cabo San Lazaro northward starting Tue 
night, as high pressure strengthen across the region behind the 
dissipating cold front. Gentle to moderate winds will prevail 
across the remaining waters to the east. 

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

The pressure gradient between a surface ridge extending southward over
the northwestern Caribbean Sea and the EPAC monsoon trough is 
supporting fresh to strong NE gap winds and seas of 5 to 7 ft in 
the Papagayo region. Light to gentle winds prevail elsewhere N of
the monsoon trough, except well offshore Guatemala where 
moderate to fresh winds are downwind from a Gulf of Tehuantepec 
gap wind event, with similar winds near the Gulf of Fonseca. 
South of the monsoon trough and 06N, gentle to moderate 
S to SW winds and 3 to 5 ft seas in moderate S to SW swell 
prevail. Except for seas of 6 to 8 ft well offshore of western
Guatemala, where NW swell from the Gulf of Tehuantepec gap wind 
event prevails. Active convection is present S of 09N from the
coast of Colombia westward across the near and offshore waters of Panama
and Costa Rica, and extends beyond 90W. 

For the forecast, the pressure gradient between high pressure 
over the western Caribbean and the eastern north Pacific monsoon 
trough will support pulsing fresh to strong NE gap winds in the 
Papagayo region into early Wed, then moderate to fresh 
thereafter. Gales in the Tehuantepec region will continue to
generate northwesterly swell and rough seas well offshore 
Guatemala through early Mon. Elsewhere, winds will be moderate 
or weaker with moderate seas through mid-week, pulsing to 
moderate to fresh in the Gulf of Panama at times. Seas will 
build by mid-week in W-NW swell.

...REMAINDER OF THE AREA...

Please read the Special Features section about large NW swell 
over the waters north of the ITCZ/monsoon trough through the 
next several days.

A cold front is just north of the NW waters with moderate to fresh
SW winds beginning to creep into the northwest waters N of 27N
and W of 131W. High pressure at 1024 mb is ahead of the front 
near 27N129W. Light to gentle anticyclonic winds are elsewhere 
north of 22N and east of the front to 120W. The pressure 
gradient between the high pressure and lower pressure in the 
vicinity of the ITCZ is supporting moderate to fresh winds north 
of the ITCZ to 21N and west of 118W per overnight satellite scatterometer
data, and locally to strong within 120 nm of the ITCZ west of
120W. Across the remainder of the open waters, including south 
of the ITCZ, gentle to moderate trades prevail. Aside from the 
large swell discussed above, seas are mainly in the 5 to 8 ft 
range except 7 to 10 ft S of 10N and W of 120W with the arrival
of the NW swell.

For the forecast, other than the large NW swell discussed in 
detail in the Special Features sections, little change in winds 
are forecast over the next several days, while a front manages to
push SE of 30N140W by early Mon, decaying over the northern 
waters into mid-week. New high pressure will build into the
region behind this front. Meanwhile, seas of 8 ft or greater 
will cover most of the waters west of 110W by early next week, 
and then west of 95W by mid-week.

$$
Stripling