492 
AXPZ20 KNHC 111545
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Mon Dec 11 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
1530 UTC.

...SPECIAL FEATURES...

Tehuantepec Gale Warning: A strong pressure gradient between a 
1025 mb high pressure system over the NW Gulf of Mexico and 
lower pressures in the deep tropics support gale-force winds in 
the Gulf of Tehuantepec. The gale-force winds are likely reaching
as far south as 12N with strong winds reaching near 10N. Seas 
are currently peaking around 20 ft. Gale- force winds will 
diminish by Thu morning with strong winds continuing through the 
end of the week. Seas will drop below 12 ft by Wed and below 8 ft
by Fri. 

Please read the latest High Seas Forecast and the Offshore 
Waters Forecast issued by the National Hurricane Center at 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and 
www.nhc.noaa.gov/marine/offshores.php for details on the special 
feature.

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

The monsoon trough extends from the border of Costa Rica/Panama
near 08N83W to 05N94W. The ITCZ extends from 05N49W to 06N120W to
beyond 05N140W. Scattered moderate to isolated strong convection
is noted from 05N to 11N between 118W and 134W. Scattered
moderate convection is noted from 04N to 09N between 77W and 88W. 

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

Please refer to the SPECIAL FEATURES section for details on a
Gale Warning for the Tehuantepec region due to gap winds.

A strong high pressure system over the Great Basin of the United
States sustain fresh to strong northerly winds in the Gulf of 
California. Seas in these waters are 5-8 ft. Moderate or weaker
winds are present in the offshore waters of Baja California, 
along with seas of 4-7 ft within NW swell. Gentle to moderate 
winds are occurring in the offshore waters of SW Mexico. Seas in 
these waters are 5-7 ft within NW swell. Scattered showers are
impacting the Guerrero offshore waters. 

For the forecast outside of the Gulf of Tehuantepec, the strong
winds over the Gulf of California will diminish today along with
the rough seas. A recurrence of fresh to strong NW winds over 
the Gulf of California may occur Fri into Sat. A surge of fresh
winds could bring NW swell with seas to 8 ft to the Baja
California Norte waters N of Punta Eugenia tonight into Tue. 

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

Very rough seas to 16 ft are impacting the offshore waters of
Guatemala and El Salvador due to the swell from the Gulf of
Tehuantepec gap wind event. The 8 ft seas extend as far east as
92W. Meanwhile, fresh to strong easterly gap winds prevail 
across the Gulf of Papagayo region, including the coast of 
southern Nicaragua, and extends westward to about 89W. Seas in 
these waters are 4-6 ft. Elsewhere, moderate or weaker winds and 
4-7 ft seas prevail. The highest seas are found south of the 
Galapagos islands. Most of the region is seeing northerly swell. 
Latest satellite imagery shows showers and isolated 
thunderstorms persisting in the Gulf of Panama, offshore Panama 
and Colombia.

For the forecast, the rough to very rough seas due to the Gulf 
of Tehuantepec impacting Guatemala and El Salvador will continue
to expand across the area through tonight. These seas will
subside later in the week. Fresh to strong NE-E winds are 
forecast across the Papagayo region through the end of the week 
with seas building to 9 ft tonight into Wed. Gentle to moderate 
breezes are expected elsewhere. 

...REMAINDER OF THE AREA...

The remainder of the tropical eastern Pacific continues under the
influence of a strong ridge anchored by a 1026 mb high pressure 
near 34N134W. The pressure gradient between the high pressure and
the ITCZ is causing fresh to strong easterly winds to prevail
between 07N to 22N and W of 115W. Seas in these waters 8 to 12 ft
in combined NW swell along with being enhanced by the strong
winds. South of the ITCZ, moderate to locally fresh SE to E winds
prevail with seas 7 to 10 ft. East of 100W, outside of the
influence of the Gulf of Tehuantepec, moderate to locally fresh
winds prevail with seas 5 to 8 ft. 

For the forecast, the surface ridge to the north will weaken as
it drifts S into the region Tue, diminishing the trades. Seas 
should drop below 8 ft Wed night into Thu over the tradewind 
belt. Fresh to strong NE winds associated with Tehuantepec gap 
winds will reach into the high seas waters to 10N105W with seas 
8-12 ft today into tonight. A large, long-period swell should 
reach the NW corner of the waters by Wed night and gradually 
decay while moving SE through the end of the week. 

$$
AReinhart