921 
AXPZ20 KNHC 190940
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Tue Dec 19 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 0600 UTC surface analysis and satellite imagery through
0930 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 30-40 kt in the Gulf of Tehuantepec, with 
seas peaking at around 15 ft. An overnight ASCAT pass nicely 
exhibited these winds. A tight pressure gradient will support 
gale conditions through much of the rest of the week. Seas with 
this latest gale-force gap wind event are forecast to peak near 
15 ft late tonight and Tue.

Eastern Pacific Significant Swell event: A new set of NW swell 
will move into the northwest waters midweek, and seas greater 
than 12 ft will move into the northern waters on Wed. Seas with 
this swell event will peak near 14 or 15 ft over the waters north
of 27N between 125W-133W late Wed and early Thu before starting 
to subside. 

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 08N79W to 07N86W to 04N96W and
to 05N106W. The ITCZ axis extends from 05N106W to 08N116W to 
06N131W to 07N140W. Scattered moderate to strong convection is 
within 180 nm south of the ITCZ between 119W-110W and within 
120 nm south of the ITCZ between 136W-140W. Scattered moderate 
to isolated strong convection is within 60 nm north of the trough
between 91W-95W and between 104W-107W.

...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, light to gentle 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 mainly light to gentle
winds across the rest of the offshore waters. Seas are in the 
6-8 ft range in long-period west to northwest swell off the Baja
California peninsula, and 4-5 ft elsewhere.

For the forecast, NW swell over the outer offshore forecast 
waters of Baja California between Cabo San Lazaro and Punta 
Eugenia will subside today. Low pressure is expected to approach 
far northern Baja California Norte from the W on Fri bringing 
fresh west to northwest winds. A large set of NW swell will 
begin to impact the waters west of Baja California Norte Thu, 
spreading across the Baja California Sur offshores Fri and Sat. 

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

Fresh to strong winds are over the Gulf of Papagayo, with fresh 
winds extending downstream of the Gulf to near 90W. Seas of 6-8 
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. Fresh to 
locally strong north winds along with seas of 5-7 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, with periods of
near gale force through early Thu. Winds will diminish Sat.
Northwest 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. The fresh to strong 
north winds over the Gulf of Panama will change little through
early Wed, then be at mostly fresh speeds through Fri and at
gentle to moderate speeds afterward. Elsewhere, winds are 
expected to be moderate or weaker for the next several days.

...REMAINDER OF THE AREA...

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

A cold front extends from 30N120W to 21N129W. Moderate west to 
northwest to winds are west of the front north of 28N, while 
light to gentle winds are east of the front where weak high 
pressure is present. Moderate to locally fresh trades are north 
of the ITCZ to near 16N. Light to gentle winds are elsewhere 
north of the ITCZ. Gentle to moderate winds prevail south of the 
ITCZ. Seas of 8-10 ft in a NW to N swell are north of the 
equator and west of 119W. Seas of 5-7 ft are elsewhere over the 
discussion waters.

For the forecast, winds south of the ITCZ will be in the 
moderate to fresh range through Wed, then mostly gentle speeds 
afterward. The 8 ft seas from the NW swell over the western 
waters will gradually subside, with areal coverage of 8 ft seas 
decreasing over the next few days.

$$
Aguirre