000
AXPZ20 KNHC 172046
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sun Dec 17 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 1800 UTC surface analysis and satellite imagery through
2015 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 in the 9-13 ft range. 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 14 ft on 
Tue.

Eastern Pacific Significant Swell event: A deep extratropical 
low pressure system is located north of the area near 36N135W 
with pressure of 991 mb. With the low shifting further north of 
the area, the pressure gradient has loosened enough to diminish 
winds below gale force. However, seas greater than 12 ft 
generated from this low are covering the waters N of 17N west of 
128W, peaking near 16 ft. These seas will subside tonight, 
decreasing below 12 ft 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 extends from 09N83W to 06N96W. The ITCZ 
continues from 06N96W to 04N131W to 07N140W. Scattered moderate 
convection is noted from 03N to 08N between 83W and 90W, and 
within 60 nm of the ITCZ between 103W and 134W. 

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

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

Aside from the Gulf of Tehuantepec, 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 4-7 ft range in 
long- period west to northwest swell off Baja California Norte, 
and 4-5 ft elsewhere.

For the forecast, moderate northwest winds over the Gulf of 
California will gradually diminish through the week. Large NW 
swell will reach the outer offshore forecast waters of Baja 
California between Cabo San Lazaro and Punta Eugenia tonight, 
then subside on Tue. 

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

Moderate to fresh northeast to east winds, and seas of 4-5 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. Gentle north 
winds and seas of 3-4 ft are in the Gulf of Panama. Light to 
gentle winds, and seas of 3-5 ft are elsewhere across the 
discussion waters.

For the forecast, moderate to fresh northeast to east winds in 
the Gulf of Papagayo will increase to fresh to strong early this 
week. The fresh to strong winds will continue through the week, 
reaching near gale force Mon night 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. Fresh north winds are expected over the 
Gulf of Panama starting tonight and continuing well into the 
week, reaching strong speeds Tue night through Wed night. 
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 991 mb low pressure system is centered N of the area near 
36N135W. With the area of low pressure shifting further from the
area, winds have diminished below gale force, with strong to 
near- gale force winds now found N of 26N between 130W and 136W. 
Moderate to fresh winds are elsewhere N of 24N and W of 125W. 
Moderate to fresh winds are N of the ITCZ to near 15N. Gentle to 
moderate winds are S of the monsoon trough. Light to gentle winds
are elsewhere over the discussion waters. Outside of the area of
12 ft seas, seas greater than 8 ft are found over much of the 
waters N of 07N and W of 122W. Seas of 5-7 ft prevail elsewhere 
over the discussion waters. 

For the forecast, winds south of the ITCZ will be in the 
moderate to fresh range through Mon. Swell from the Tehuantepec 
gap wind event will spread westward, with seas of 8-9 ft reaching
to near 104W tonight before starting to subside. The 8 ft seas 
from the NW swell over the western waters will spread eastward to
cover much of the waters W of 120W on Mon before starting to 
subside below 8 ft. A new set of NW swell will move into the NW 
waters midweek. Seas with this swell will peak near 15 ft over 
the northern waters early Thu before starting to subside. 

$$
AL