000
AXPZ20 KNHC 141557
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Tue Dec 14 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
1500 UTC.

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

The monsoon trough extends from 09N84W to 09N88W to 07N100W. The
ITCZ extends from 07N100W to 06N120W to beyond 08N140W. Convection
is limited.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO

A ridge across the eastern slopes of the Sierra Madre Mountains
in Mexico continues to support northerly wind flow across the 
Isthmus of Tehuantepec, resulting in strong northerly gap winds 
to 30 kt across the Gulf of Tehuantepec. Fresh to strong winds 
extend downwind to near 12N98W. Seas across this area are 8 to 
10 ft. This strong gap wind event is expected to prevail through
Wed night before diminishing significantly in strength and areal
coverage. Winds are expected to diminish to fresh to strong and 
remain confined to the Gulf of Tehuantepec Thu through Friday 
morning before shutting down.

A 1020 mb high pressure centered near 25N120W extends a ridge
across the offshore waters of Baja California and is promoting 
light to gentle winds across most of the rest of the Mexican 
offshore waters. Moderate northerly winds prevail across the 
nearshore waters from southern Sinaloa to the Cabo Corrientes 
area, while fresh S to SW winds have developed across the far 
northern Gulf of California. Seas are 2 to 3 ft in the Gulf of 
California, except 3 to 4 northern portions, and 3 to 5 ft 
elsewhere S of 24N.

An approaching cold front extending from 30N122W to 23N140W will
move into the waters W of Baja California Norte by this evening.
Fresh to strong SW winds are expected ahead of the front N of 
27N and in the northern Gulf of California tonight, with a brief
period of fresh to locally strong NW winds behind it through Wed
as well. Large NW swell has begun to move into the outer NW 
offshore waters where seas have built to 8-10 ft. This swell 
will move into the remaining N offshore waters overnight, with 
building seas areawide expected through Wed, peaking at 10-15 ft 
N of 24N early Wed morning.

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

Fresh to strong NE to E continue across the Papagayo region with
seas to 8 ft. These gap winds are forecast to continue through 
Wed, and then diminish to moderate to fresh through Fri night. 
Gentle to moderate northerly winds and seas 3 to 4 ft in the 
Gulf of Panama are forecast to pulse nightly through Wed night. 
Moderate S to SW winds are south of the monsoon trough with seas 
to 6 ft in SW swell. Light to gentle variable winds are 
elsewhere. These conditions are forecast to remain for much of 
the week.

REMAINDER OF THE AREA...

High pressure of 1020 mb is centered near 25N120W. A cold front 
is moving SE across the northern waters and extends from 30N122W
to 23N140W. This front is forecast to continue moving E-SE into 
mid-week, accompanied by very large NW swell. Seas of 12 to 18 ft
in NW swell are behind the front. A pair of weakening troughs 
are to the south of the front, along 110W/111W and 130W, with 
the resultant pressure gradient producing a zone of moderate to 
fresh E winds from 10-20N between 110W and 140W. 

Large NW swell will continue to build across the NW waters and 
move east of 120W this afternoon. Seas of 12 to 18 ft will
continue to propagate across the waters N of 20N and W of 110W
through tonight before gradually subsiding from W to E on Wed.  

$$
GR