000
AXPZ20 KNHC 210404
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Thu Dec 21 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 0000 UTC surface analysis and satellite imagery through
0300 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: High pressure along the 
eastern slopes of Mexico is enhancing northerly winds funneling
through the Chivela Pass, which is supporting gale-force north to
northeast winds in the Gulf of Tehuantepec, with seas peaking at
around 12 ft. Gale conditions will continue through Thu evening.
Strong to near-gale force winds will then continue through Fri 
night before diminishing Sat.

Eastern Pacific Significant Swell event: A set of large NW swell
with seas of 12 to 16 ft is currently occurring over the waters
north of 27N between 125W and 137W. Seas with this swell event 
will peak tonight into early Thu before starting to subside. Seas
of 12 ft or greater will propagate southeastward, to cover waters
as far south as 25N and as far east as 122W early Thu. Seas will
subside below 12 ft by early Fri morning.

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 05N77W to 04N96W. The ITCZ
extends from 04N96W to 07N125W to 06N140W. Scattered moderate 
convection is noted from 03N to 09N between 110W and 125W, and
from 04N to 08N between 129W and 140W.

...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 gale in the Gulf of Tehuantepec, a weak pressure 
gradient prevails across the area. Gentle winds are west of the 
Baja California peninsula and the open offshore waters. Seas are 
4-7 ft west of Baja California, 2 ft or less over the Gulf of 
California, and 5-7 ft elsewhere over the open waters off Mexico,
except 8-12 ft closer to the Tehuantepec region.

For the forecast, a cold front will move into the waters west of
Baja California Thu ahead of a low pressure that will 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
late tonight, spreading across the Baja California Sur offshores
Thu night through Fri night. Another set of NW swell will move 
into the Baja California Norte waters this weekend.

...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 
region, with fresh winds extending downstream of the Gulf to near
07N95W. Seas of 8-10 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 
7-9 ft range over the outer offshore waters of Guatemala and El 
Salvador. Fresh to strong northerly winds prevail over the Gulf 
of Panama. These winds likely extend downstream to 05N. Seas are
7 to 8 ft in the area. Gentle to moderate winds and seas of 5-7 
ft are elsewhere south of the monsoon trough.

For the forecast, strong to near-gale force NE winds will 
continue over the Gulf of Papagayo through Thu night. Then, fresh
to strong winds will prevail through Fri night, and diminishing 
on Sat. NW swell generated by the Gulf of Tehuantepec gale-force
gap wind event will continue to impact the outer Guatemala and 
El Salvador offshore waters through Thu night. Fresh to strong 
north winds will continue over the Gulf of Panama through Thu
night before diminishing to moderate Fri. 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 northwestern portion of the basin.

A cold front extends from 30N121W to 26N127W, with a dissipating
cold front continuing from that point to 23N140W. To the NW of 
the front, fresh NW to N winds and 8 to 16 ft seas prevail, in 
NW to N swell. Fresh trades prevail north of the ITCZ to 20N and
west of 125W. Moderate trades prevail north of the ITCZ to 18N 
and east of 125W. Moderate winds prevail south of the ITCZ. Seas
of 8-9 ft in NW to N swell are south of 13N and west of 100W. 
Seas of 5-8 ft are elsewhere over the discussion waters.

For the forecast, low pressure will approach 30N from the north 
tonight. This will support fresh to strong winds over the waters 
N of 28N and E of 134W tonight through Fri. The low is already
spreading a large set of NW swell over the area, discussed in 
the special features section above. Seas greater than 8 ft 
associated with this swell will propagate across the area 
through the end of the week and into the weekend. Areal coverage 
of seas greater than 8 ft will start to decrease by Sun as the 
seas gradually subside.

$$
Hagen