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Eastern North Pacific Tropical Weather Discussion

AXPZ20 KNHC 281608

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Thu Oct 28 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 1200 UTC surface analysis and satellite imagery through
1550 UTC.


Gulf of Tehuantepec Gale Warning: A cold front moving southward 
across the Gulf of Mexico will enhance northerly gale force 
winds across the Gulf tonight into early Friday. Winds will 
diminish below gale force by Friday but remain fresh to strong 
through Saturday. Peak seas are estimated to reach up to 12 ft 
late tonight into Friday. Refer to the latest High Seas Forecast 
issued by the National Hurricane Center at: for details. 


A tropical wave axis is analyzed along 106W north of 07N, moving
W at around 10 kt. Scattered moderate and isolated strong convection
is noted where it intercepts the monsoon trough from 13 to 09N 
between 104W and 109W.


The monsoon trough extends from 11N73W to across Costa Rica and 
exits into the Eastern Pacific Ocean near the Papagayo region to
near 09N96W, then resumes near 15N102W to a 1010 mb low pressure
near 11N116W and ends near 11N140W. Scattered moderate convection
is noted about 200 nm south of the monsoon trough E of 95W. An
area of scattered to moderate convection is note W of the monsoon 
trough from 14N to 08N between 97W to 101W. 


Fresh to strong winds are occurring in the Gulf of California
south of 30N and west of 110W with moderate to fresh winds 
elsewhere in the Gulf. Seas are 3 to 6 ft in the Gulf, except to 
7 ft in the central part. Gentle to moderate NW-N winds prevail 
elsewhere offshore of Mexico, except SW-W offshore from Jalisco
south to Michoacan. Large NW swell continues to propagate offshore
of Mexico with seas of 8 ft or greater west of 101W, highest up 
to 11 ft from the Revillagigedo Islands to the northwest. Seas of
4 to 7 ft prevail east of 101W.

For the forecast, large NW swell west of 100W will gradually subside
this afternoon. A reinforcing set will arrive west of Baja California
tonight into Friday, subsiding by the weekend. Gentle to moderate 
northerly winds will prevail west of Baja California, except light
to gentle Sat through early Sun. Fresh to strong winds in the central
Gulf of California, and moderate to fresh elsewhere in the Gulf 
of California will diminish tonight. 


Gentle to moderate S-SW winds are occurring south of the monsoon
trough, locally fresh near the entrance to the Gulf of Guayaquil,
with mainly light and variable winds north of the monsoon trough.
Seas are 4 to 6 ft, except 5 to 7 ft offshore of Ecuador in a
moderate southerly swell.

For the forecast, mainly gentle to moderate SW winds will persist
south of the monsoon trough, with light to gentle variable winds
north of the monsoon trough, pulsing to moderate to fresh in the
Papagayo region Sat night through Mon night. A moderate southerly
swell will persist through Sat, subsiding thereafter.


Moderate to fresh trades dominate the waters north of the convergence
zone with gentle to moderate southerly flow south of the convergence
zone. Large NW-N swell continues to propagate across the open waters
with seas of 8 to 9 ft or greater west of 103W. The peak seas have
subsided a bit, now around 12 ft near 11N116W. Seas of 6 to 8 ft in
remnant mixed swell prevail east of 103W.

For the forecast, winds will diminish by the end of the week into
the weekend across the majority of the waters as the pressure 
gradient slackens. The next cold front is forecast to slip 
southeast of 30N140W by early Sun with fresh to strong SW winds 
ahead of it. The front will dissipate and associated winds will 
diminish early next week. Meanwhile, the large NW-N swell will 
gradually decay through the end of the week into the weekend. A 
new set of NW swell will breach southeast of 30N140W early Sun 
with the next front, propagating southeast through early next