000
AXPZ20 KNHC 212111
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Thu Oct 21 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

Disorganized showers and thunderstorms within a few hundred miles of 
the southern coast of Mexico are associated with a broad area of 
low pressure located just to the southwest of the Gulf of Tehuantepec.
Environmental conditions are expected to be conducive for gradual
development of this system during the next several days, and a 
tropical depression is likely to form by this weekend while the 
system moves slowly west-northwestward to northwestward near or 
just offshore the southern coast of Mexico. Regardless of development,
this system could bring an increase in winds and seas across the
southern coast of Mexico from Oaxaca to Michoacan over the next 
48-72 hours. Currently, this system has a medium chance of tropical
cyclone formation through 48 hours, and a high chance through 5 
days. Please, see latest Tropical Weather Outlook at 
www.hurricanes.gov

...TROPICAL WAVES...

A tropical wave is along 137W extending from 05N to 16N, moving 
westward at 10 to 15 kt. Convection is limited associated with 
the wave.

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

The monsoon trough extends from northern Costa Rica near 10N84W 
to 1011 mb low pres located near 13N97W to 10N105W to 1011 mb 
low pres situated near 12N116W to 08N134W to 12N140W. Aside from
the convection associated with the low pres located near 13N97W,
scattered moderate convection can be found from 09N to 15N between
90W and 110W, from 10N to 15N between 113W and 120W, and from 
07N to 11N between 120W and 131W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

High pressure of 1022 mb centered near 29N124W extends a ridge 
across the offshore forecast waters of Baja California producing
gentle to moderate NW to N winds with seas of 3 to 5 ft in NW 
swell. In the Gulf of California, gentle to moderate winds
prevail with seas of 1-3 ft. Based on recent scatterometer data,
winds are on increase just S of Puerto Angel due to the presence
of a broad area of low pressure located SW of the Gulf of 
Tehuantepec.

For the forecast, the broad area of low pressure continues to 
produce disorganized showers and thunderstorms within a few 
hundred miles of the southern coast of Mexico. Please, see the 
Special Features section for more details. Otherwise, moderate to
fresh NW-N winds are expected N of Punta Eugenia Fri through Sat
night with building seas of 10 or 11 ft in NW swell. In the Gulf
of California, mainly gentle to moderate NW winds will prevail. 
Winds will veer to the S and then SW in the northern part of the 
Gulf by Fri night as a weakening cold front approaches from the 
west.

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

Mainly gentle to moderate S to SW are expected across the forecast
area S of the monsoon trough. N of the monsoon trough, expect 
light to gentle winds through most of the forecast period. By Sat
night into Sun, expect building seas in SW swell between Ecuador
and the Galapagos Islands. This swell event is forecast to reach
the offshore forecast waters of western Panama on Sun, building 
seas of up to 8 ft. 

REMAINDER OF THE AREA...

A new cold front is moving across the NW corner of the forecast 
area and extends from 30N138W to 29N140W. Large and long period 
NW swells follow the front forecast to reach 30N128W to 27N140W 
on Fri, and from 30N119W to 26N140W on Sat while weakening. 
Moderate to fresh SW winds are between the front and the 1022 mb
high centered near 29N124W. Currently, seas of 8 to 10 ft in NW 
swell cover the area NW of a line from 30N121W to 28N121W to 
21N130W to 19N140W. Highest seas of 12 to 15 ft are expected in 
the wake of the front by Fri morning. This swell event will 
continue to propagate across the forecast region through at least
Sat, with seas in excess of 8 ft covering much of the waters N 
of 20N W of 120W. 

$$ 
GR