000
AXPZ20 KNHC 190947
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sun Dec 19 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
0950 UTC.

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

The monsoon trough extends from northern Costa Rica near 08N85W 
to 08N98W. The ITCZ begins from 08N117W to 08N132W, then continues
W of the 1011 mb low pres from 08N133W to beyond 07N139W. Scattered
showers are noted 240 nm south of the monsoon trough and E of 82W 
and scattered moderate convection is along the ITCZ from 06N-12N
between 116W-132W. 

OFFSHORE WATERS WITHIN 250 NM OF MEXICO

Surface ridging weakens across the offshore waters on Baja 
California, with gentle to moderate northerly winds from Punta 
Eugenia south to near 24N. Light and gentle winds are noted 
elsewhere. High pressure over the State of Nevada is supporting 
moderate to fresh NW to N winds across the north and central 
parts of the Gulf of California to near the entrance of the Gulf,
clearly indicated by the recent scatterometer over the Gulf of 
California. Light to gentle winds are seen elsewhere over the 
open waters off Mexico, including the Gulf of Tehuantepec. Seas 
are in the 6-8 ft range N of Cabo San Lazaro, and 4-6 ft 
elsewhere over the open waters off Mexico. Seas of 4-6 ft prevail
in the Gulf of California. 

For the forecast, fresh winds in the north and central parts of 
the Gulf of California will gradually decrease today. A new gap 
wind event is forecast in the Tehuantepec area beginning Sun 
night, with gale conditions possible on Tue and Tue night, then 
fresh to strong northerly winds are expected to persist in the 
Gulf of Tehuantepec through Thu night. Seas are forecast to build
up to 12 ft with the strongest winds. 

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

Moderate to fresh NE winds are observed in the Gulf of Papagayo.
Light to gentle winds are noted elsewhere north of the monsoon 
trough while gentle to moderate S to SW winds are noted south of
the monsoon trough per scatterometer data. Seas are generally 4 
to 6 ft across the offshore forecast waters. 

For the forecast, NE to E winds will pulse to fresh to strong in
the Papagayo region through the next several days and into next 
week, particularly during the overnight and early morning hours
each day. Gentle to moderate winds will prevail elsewhere. No 
significant swell events are forecast during the next several
days.

REMAINDER OF THE AREA...

The pressure gradient across the offshore waters has relax some 
with recent scatterometer data indicating light to gentle winds
from 20N to 31N and E of 140W, ahead of the next cold front. 
South of 20N, the pressure gradient between the high pressure and
lower pressure near the ITCZ is supporting an area of fresh to 
locally strong trade winds from 13N to 21N W of 119W. Winds 
increase to 20-25 kt near a surface trough that extends from 
12N108W to a 1011 mb low pres located within the monsoon trough 
near 09N113W and further W near a second low located at 08N132W. 
NW to N swell continues to propagate mainly across the waters 
west of 110W, producing seas of 8-10 ft. Seas of 6-8 ft are noted
elsewhere roughly S of 17N between 100W-110W.

For the forecast, the swell event affecting mainly the waters W 
of 110W will gradually decay today. The next cold front will 
enter the NW corner of the forecast area today, with fresh to 
strong winds on either side of the front. The front will reach 
from 31N131W to 25N140W by early Mon morning. Another set of 
long period NW swell will follow the front, building seas to 8-12
ft.

$$
Torres