000
AXPZ20 KNHC 181003
TWDEP

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

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

The monsoon trough extends from the southern coast of Costa Rica
near 09N83W to 10N106W. The ITCZ continues from 10N106W to
08N123W, then from 07N128W to 08N140W. Scattered moderate 
convection is noted from 07N to 14N between 97W to 112W and 
between 128W to 140W. 


OFFSHORE WATERS WITHIN 250 NM OF MEXICO

A surface trough previously analyzed across the Gulf of California
has dissipated. Observations indicate an area of fresh to strong
NW to N winds north of 24N to near 27N and E of 119W. Seas range
between 8 to 11 ft. A 1028 mb high pressure dominates the 
offshore waters on Baja California producing mainly gentle to 
moderate north to northeast winds. Gentle to moderate northerly 
winds are noted per scatterometer data from Manzanillo to near 
Puerto Escondido and moderate to fresh N of 19N to the entrance 
of the Gulf of California. Fresh NE winds are noted in the Gulf 
of Papagayo based on recent satellite derived wind data. Light to
gentle winds are elsewhere over the open waters off Mexico. Seas
are in the 6-7 ft range N of 20N and W of 110W and 4-7 ft 
elsewhere over the open waters off Mexico. Seas of 3-5 ft are in 
the Gulf of California. 

For the forecast, NW swell will continue to dominate the 
offshore forecast waters of Baja California today before it 
begins to decay into Sunday. Fresh to strong winds will develop 
in the north and central parts of the Gulf of California today
through Sat evening. A new gap wind event is expected in the 
Tehuantepec region beginning on Sun night, with gale conditions 
possible on Tue. Seas are forecast to build to 10-13 ft with the
strongest winds. 

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

Fresh to strong NE winds are observed in the Gulf of Papagayo 
region tonight. Light to gentle winds are noted elsewhere north 
of the monsoon trough. Gentle to moderate S to SW winds are also
noted south of the monsoon trough. Seas ranged between 3 to 5 ft
in mixed swell.

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 through early next week.

REMAINDER OF THE AREA...

Surface high pressure centered near 33N132W dominates the waters
north of the ITCZ with a pretty tight pressure gradient. As a 
result, pressure gradient between the ridge and lower pressure 
in the vicinity of the ITCZ is supporting fresh to locally strong
trade winds north of the ITCZ to near 26N and west of 120W. 
Gentle to moderate winds prevail elsewhere. NW to N swell is 
dominating the waters west of 110W, producing seas of 8-11 ft. 
Seas of 5-7 ft are noted elsewhere. The aforementioned 
dissipating cold front has ushered in a set of reinforcing NW 
swell with seas up to 12 ft near 30N130W.

For the forecast, an area of fresh to locally strong trade winds
will persist across the west-central waters today. The large NW 
to N swell will gradually decay through the weekend. The next 
cold front is forecast to move southeast of 30N140W early Sun 
with fresh to locally strong winds on either side of the front. 
The front will slowly progress east-southeast through early next 
week. The front will bring another NW swell event, building seas 
to 8-12 ft.

$$
Torres