992 
AXPZ20 KNHC 170532 CCA
TWDEP 

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
0405 UTC Sun Dec 17 2023

Corrected Offshore Waters Within 250 nm of Central America, 
Colombia, and within 750 nm of Ecuador 

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
0345 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: Gale-force north to northeast 
winds of 30-40 kt are presently occurring in the Gulf of 
Tehuantepec, with seas reaching a peak of about 10 ft. These 
conditions will change little through Mon as high pressure ridges
southward over eastern Mexico. Seas are forecast to reach a peak
of 14 ft on Tue.

NW Eastern Pacific Gale Warning and Significant Swell event: A 
deep extratropical low pressure system is located north of the 
area near 34N137W with pressure of 986 mb. A stationary front out 
ahead of this low pressure system stretches southward to 30N126W 
to 22N130W and to 14N140W. Meanwhile, a cold front is just
northwest of the discussion area. Gale-force southwest to west 
winds are north of 28N and between 134W-140W. These winds will 
lift north of 30N early on Sun as the low tracks to the 
northeast. An extensive set of northwest swell will propagate 
through the northwest and central sections of the area through 
Tue, at which time it will have reached the southern half of the 
area west of about 110W, but will have decayed quite a lot by 
that time. Seas are currently peaking to 24 ft within the area of
gale winds. Very rough seas of 15-20 ft in NW swell are 
elsewhere north of 25N west of 134W, and 8-12 ft over remainder 
waters north of 10N and west of 122W. Seas of 8 ft or greater 
will extend as far south as 04N and west of 118W by late on Mon.

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 axis extends from northwest Colombia to
northern Costa Rica, then to 10N85W to 07N93W and to 06N99W,
where latest scatterometer data indicates that it transitions
to the ITCZ to low pressure near 08N103W 1007 mb and continues 
to 06N113W to 07N125W to 08N133W and to 09N140W. Numerous
moderate to strong convection is within 120 nm south of the 
ITCZ between 102W-106W. Scattered moderate convection is
seen from 06N to 09N between 84W-86W, also within 60 nm of 
trough between 92W-95W and within 30 nm of the ITCZ between 
106W-112W.

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

Please refer to the Special Features section for details on an 
ongoing Gulf of Tehuantepec Gale Warning.

Fresh northwest winds are over the central and southern sections
of the Gulf of California. A weak pressure gradient dominates 
the Mexican offshore waters, outside of the Gulf of Tehuantepec. 
Moderate or weaker winds and slight to moderate seas continue 
across the rest of the offshore waters. Seas across the Baja 
California offshore waters and over the southern Mexico offshore 
waters are in the 4-6 ft range due to long-period west to 
northwest swell.

For the forecast, the fresh northwest winds over the central and
southern Gulf of California sections will diminish to moderate 
speeds on Sun and to gentle speeds on Mon. Winds in the Gulf of 
California become light and variable Tue through Thu night. Seas 
to around 8 ft associated with a large swell event will reach the
outer offshore forecast waters of Baja California between Cabo 
San Lazaro and Punta Eugenia by Sun night. These seas will 
subside on Tue.

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

Gentle to moderate northeast to east winds are in the Gulf of 
Papagayo region, including the coast of southern Nicaragua. Seas 
with these winds are in the range of 3-5 ft. To the northwest of 
the Gulf of Papagayo region, seas of 6-9 ft in a northwest swell 
generated by the Gulf of Tehuantepec gap wind event are over the 
outer offshore waters of Guatemala and El Salvador. Gentle north 
winds and seas of 3-4 ft are in the Gulf of Panama.

Scattered showers and isolated thunderstorms are over the
offshore waters of Costa Rica and Panama.

For the forecast, the gentle to moderate northeast to east winds
in the Gulf of Papagayo will increase to fresh to strong 
beginning Mon, and continue through next week while expanding to 
the southwest. These winds are expected to reach near-gale force 
Tue and Wed. Rough seas are expected over the Guatemala and El 
Salvador offshore waters Sun due to the Gulf of Tehuantepec gap 
wind event. Elsewhere, winds are moderate or weaker for the next 
several days. 

...REMAINDER OF THE AREA...

Refer to the section above for details on the Gale Warning and
significant swell event for the western portion of the basin.

A deep extratropical low pressure system is located N of the 
area near 34N137W with a pressure of 986 mb. A stationary front out 
ahead of this low pressure system stretches southward to 30N126W 
to 22N130W and to 14N140W. Meanwhile, a cold front is just
northwest of the discussion area. A tight pressure gradient 
associated with this system will remain in place over the 
northwest corner of the forecast area through Sun. Outside of the
warning area described above under Special Features, a N to S 
high pressure ridge offshore southern California and northern 
Baja California controls the gradient across the remainder of the
forecast waters north of the ITCZ and west of 110W. Gentle to 
moderate winds are on either side of the ITCZ/Monsoon Trough with
seas of 5-7 ft in mixed swell.

For the forecast, gale force winds over a portion of the
northwest forecast waters will lift northeast of the area early
on Sun as the deep low tracks to the northeast. The trade winds 
north of the ITCZ to near 14N will increase slightly to fresh 
speeds through Sun. Winds south of the ITCZ will be in the 
moderate to fresh range through Mon. Fresh to strong winds from 
the gap wind event of Tehuantepec will merge into the trade winds
between 100W-104W by late Sun. Swell from the Tehuantepec gap 
wind event will spread southwest and west reaching to near 104W 
by late Sun, with generated seas of 8-9 ft.

$$
Aguirre