150 
AXPZ20 KNHC 181459
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Mon Dec 18 2023

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
1445 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: The pressure gradient between
high pressure along the eastern slopes of Mexico and the eastern
north Pacific monsoon trough is supporting gale-force north to 
northeast winds of 30-35 kt in the Gulf of Tehuantepec, with 
seas peaking at around 11 ft. A tight pressure gradient will 
support gale conditions through much of the week. Seas with this 
latest gale-force gap wind event are forecast to peak near 15 ft
late tonight and on Tue.

Eastern Pacific Significant Swell event: NW swell over the far NW
waters is slowly subsiding. Seas are peaking near 13 ft over the
waters north of 24N and west of 135W. Seas will further subside 
and are expected to decrease below 12 ft today. 

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

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

The monsoon trough extends from 09N84W to 06N97W. The ITCZ
continues from 06N97W to 07N128W to 07N140W. Scattered moderate
convection is noted from 01N to 10N between 115W and 130W. 

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

Please see the Special Features section for details on the 
ongoing Gulf of Tehuantepec Gale Warning.

Aside from the Gulf of Tehuantepec, gentle to moderate northwest
winds, and seas of 1-3 ft, are over the Gulf of California. A 
weak pressure gradient dominates the Mexican offshore waters 
outside of the Gulf of Tehuantepec, with moderate or weaker winds
across the rest of the offshore waters. Seas are in the 5-8 ft 
range in long- period west to northwest swell off the Baja 
California peninsula, and 4-5 ft elsewhere.

For the forecast, moderate northwest winds over the Gulf of
California will gradually diminish through the week. NW swell 
over the outer offshore forecast waters of Baja California 
between Cabo San Lazaro and Punta Eugenia will subside on Tue. 
Low pressure may approach far northern Baja California Norte from
the W on Fri bringing fresh west to northwest winds. A large set
of northwest swell will begin to impact the waters west of Baja 
California Norte Thu. 

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

Strong to near gale force winds are over the Gulf of Papagayo. 
Fresh northeast to east winds extend downstream of the Gulf to 
near 90W. Seas of 5-6 ft, are over and downstream of the Gulf of
Papagayo region. Northwest swell generated by the Gulf of 
Tehuantepec gale-force gap wind event is supporting seas in the 
6-8 ft range over the outer offshore waters of Guatemala and El 
Salvador. Moderate to fresh north winds, and seas of 4-6 ft, are
over the Gulf of Panama. Gentle winds, and seas of 4-5 ft, are 
elsewhere south of the monsoon trough.

For the forecast, fresh to strong northeast to east winds in the
Gulf of Papagayo will continue through the week, reaching near 
gale force tonight tonight through Wed. NW swell generated by the
Gulf of Tehuantepec gale-force gap wind event will impact the 
outer Guatemala and El Salvador offshore waters for much of the 
week. Moderate to fresh north winds are over the Gulf of Panama. 
These winds are expected to continue well into the week, reaching
strong speeds tonight through early Wed. Elsewhere, winds are 
expected to be moderate or weaker for the next several days.

...REMAINDER OF THE AREA...

Please see above for details on a significant swell event over 
the western portion of the basin.

A cold front extends from 30N125W to 21N131W. Moderate winds are
west of the front as well as within 180 nm east of the front.
Moderate to locally fresh trades are N of the ITCZ to near 15N.
Light to gentle winds are elsewhere N of the ITCZ. Gentle to
moderate winds prevail S of the ITCZ. Aside from the area of 12
ft seas discussed above, seas are greater than 8 ft over the
waters N of 05N and W of 120W. Seas of 5-7 ft are found elsewhere
over the discussion waters. 

For the forecast, winds south of the ITCZ will be in the 
moderate to fresh range through midweek. The 8 ft seas from the 
northwest swell over the western waters will start to subside
today, with areal coverage of 8 ft seas decreasing. A new set of
northwest swell will move into the northwest waters at midweek. 
Seas with this swell will peak near 14 or 15 ft over the northern
waters north of 29N between 125W-132W early Thu before starting 
to subside. 

$$
AL