000
AXPZ20 KNHC 180834
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Thu Nov 18 2021

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
0800 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: A cold front is forecast to
move through the Gulf of Mexico today into Fri with high 
pressure building behind it across eastern Mexico. The building 
high combined with lower pressure south of southern Mexico will 
support a gale-force northerly gap wind event from early Fri 
through Sat morning. Seas will build to around 12 ft during the 
event. Please see the latest NWS High Seas Forecast issued by 
the National Hurricane Center at 
website://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more 
information.

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

The monsoon trough extends from 10N85W to 1012 mb low pres near 
10N121W to 08N128W. The ITCZ extends W of a trough near 07N132W 
to 08N140W. Scattered moderate convection is noted from 07N to 
13N between 114W and 122W. Scattered showers prevail along the 
monsoon trough between 95W and 105W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see the Special Features section above for details on a
Gulf of Tehuantepec Gale Warning.

Fresh N-NE winds are across the Gulf of Tehuantepec with seas to
6 ft. A surface ridge extends across the offshore waters with 
mainly gentle to moderate winds across the waters outside of the 
Tehuantepec region. Seas are in the 4 to 6 ft range across the 
open waters. Seas are 2 to 4 ft in the southern Gulf of California,
and 3 ft or less in the central and northern Gulf of California.

For the forecast, moderate to fresh winds will prevail across 
the Tehuantepec area today. A gale force northerly gap wind 
event is forecast in the Gulf of Tehuantepec early Fri through 
Sat morning. Fairly tranquil conditions are forecast elsewhere 
through the upcoming weekend. Gap winds may approach gale-force 
once again in the Gulf of Tehuantepec by early next week. Fresh 
to strong NW-N winds may develop in the northern Gulf of 
California early next week.

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

Moderate to fresh winds prevail across the Papagayo region. 
Otherwise, light to gentle winds are noted north of the monsoon 
trough. Gentle to moderate southerly winds prevail south of the 
monsoon trough. Seas are in the 4 to 7 ft range across the 
majority of the offshore waters, highest south of Panama and west
of Colombia and Ecuador. Scattered showers and thunderstorms are
noted south of Panama and Costa Rica, and west of Colombia.

For the forecast, moderate to fresh winds will prevail in the 
Papagayo region through Fri. Fresh to strong winds will return 
Fri night through Sat, then moderate to fresh thereafter. Gentle 
to moderate winds will prevail across the rest of the area 
through the next several days.

REMAINDER OF THE AREA...

A broad and weak ridge extends from a 1024 mb surface high 
centered near 30N130W to near 20N112W. A surface low is embedded
in the monsoon trough, with a 1012 mb low pressure area near 
10N121W. A surface trough is west of the low extending along 
130W. No significant convection is noted near the trough. 
Moderate to locally fresh trades are noted north of the 
convergence zone to 21N, with gentle to moderate winds north of 
there under the ridge. Gentle to moderate southerly flow prevails
south of the monsoon trough. Seas of 5 to 7 ft prevail south of 
21N, locally to 7 ft near 12N118W, with 4 to 6 ft north of 22N, 
highest along 30N between 120W and 130W.

For the forecast, little change is expected through the end of
the week. A cold front may drop south into the far northern 
waters Fri night. High pressure may build behind the front with 
freshening winds for the end of the weekend into early next week.
Seas may build to around 8 ft in the west-central waters north of
the ITCZ this weekend with the freshening winds and lengthening 
fetch.
 
$$
ERA