000
AXPZ20 KNHC 120253
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Fri Nov 12 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 0000 UTC surface analysis and satellite imagery through
0350 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: The pressure gradient between 
high pressure that will build in behind a Gulf of Mexico cold 
front and lower pressure S of Mexico will result in the 
development of a gale-force gap wind event over the Gulf of 
Tehuantepec beginning Sat afternoon, or possibly sooner. Model 
guidance indicates that peak winds will be at about 35 kt late 
on Sat, with seas to near 12 ft. Swell generated by this event 
will propagate downstream of the Gulf of Tehuantepec, with seas 8
ft or greater reaching as far south as 10N and west to near 103W
on Sun. Winds are forecast to drop below gale-force Sun afternoon
into Mon, then increase back up to gale-force at similar speeds 
late on Mon. 
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 09N84W to 07N94W. The ITCZ begins
near 07N94W to 06N105W to 10N120W then resumes near 10N130W to
beyond 09N140W. A surface trough extends from 08N126W to 16N125W.
Scattered moderate convection is associated with the trough from
07N to 16N between 120W and 130W.  
 
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...Updated

Please see the Special Features section above for details on an 
upcoming Gulf of Tehuantepec gale event.

Surface ridging continues to extend to the Baja California Norte
offshore waters, supporting gentle to moderate NW winds to Cabo
San Lazaro and light to gentle variable winds along the S and SW
Mexico offshore waters. NW swell is generating seas in the 5 to 7
ft range W of the Baja peninsula while SW swell is supporting
seas of 4 to 5 ft across the S and SW offshore waters.  


Mainly fresh northwest winds are also found over most 
of the Gulf of California, strongest through central portions. 

Seas are in the 3-6 ft range in the Gulf of California.

Fresh winds offshore of Baja California will gradually diminish 
to gentle through Fri afternoon as high pressure north of the 
area weakens. Fresh north winds inside the Gulf of California 
will diminish to gentle to moderate by Fri evening. Strong to 
near gale-force north winds will return to the Gulf of 
Tehuantepec region late tonight into early Fri. These winds are 
expected to reach gale- force early Sat afternoon, or possibly 
sooner as high pressure builds in behind another cold front that 
is forecast to sweep across the southern Gulf of Mexico.

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

Moderate to fresh gap winds remain across the Papagayo region, 
with gentle to moderate winds elsewhere north of the monsoon 
trough. These winds may briefly pulse to strong speeds on Sun. 
Gentle to moderate south to southwest winds are south of the 
monsoon trough. Seas of 4-6 ft due to a southwest swell are over 
the offshore waters.

Gentle to moderate south southwest winds will persist south of 
the monsoon through the forecast period. Winds will weaken across
and downwind of Papagayo today but return to moderate to fresh
beginning on Fri and into early next week.

REMAINDER OF THE AREA...

A strong 1030 mb high pressure center is analyzed north of the 
area near 35N129W. It has a ridge extending west-southwestward 
to 30N140W and continuing southwestward to well west of 140W. 
The resultant pressure gradient between the high and lower 
pressure within the monsoon trough and in the vicinity of the 
ITCZ is supporting moderate to fresh northeast to east winds 
north of the ITCZ and monsoon trough to near 23N and west of 
about 120W, with gentle to moderate winds north of about 25N. 
Gentle to moderate winds prevail south of the monsoon trough and 
ITCZ. The remnant lows of Sandra near 12N136W 1011 mb and Terry 
near 12N125W 1010 mb are accompanied by areas of northeast to 
east 20-25 kt winds to their north along with higher seas peaking
to 12 ft. A trough extends from the low near 12N125W to 09N130W 
and to the low near 12N136W. Satellite imagery shows scattered 
moderate to isolated strong convection within 180 nm south of 
the trough between 123W-125W, and within 90 nm SE and 120 nm SW 
quadrants of the low near 12N125W. Scattered moderate convection 
is seen north of the trough within 60 nm 12N129W.

Elsewhere, seas are in the 8-10 ft range due to mixed northeast 
and northwest swell across the trade wind belt west 120W. Seas 
in the 6-8 ft range are elsewhere.

The aforementioned high pressure ridge will remain across the 
northern waters maintaining a zone of fresh trades south of 
about 23N and west of 124W through most of Sat. These trades will
gradually decrease in coverage through the weekend as the 
remnant low of Sandra weakens further to a trough and shifts to 
west of 140W, and the remnant low of Terry reaches the far 
western part of the area. As a consequence, seas will subside to 
8 ft across the trade wind belt, but confined to west of 135W by 
Sun.
 
$$
Ramos