000
AXPZ20 KNHC 290831
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Tue Dec 29 2020

Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 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
0830 UTC.

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

The monsoon trough extends from 08N78W to 09N84W to 05N100W. The
ITCZ continues from 05N100W to 08N120W beyond 07N140W. Scattered
moderate convection is noted from 06N to 09N between 120N to 
130W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

A scatterometer satellite pass from 0330 UTC indicated 20 to 30
kt northerly gap winds in the Gulf of Tehuantepec. These winds 
will diminish through today as high pressure north of the area 
weakens. Seas are peaking at 8 to 10 ft. The next gap wind event 
should return by late Sat as a cold front moves through the Gulf 
of Mexico. This likely will be a gale- force event on late Sat 
and Sun.

Farther north, a weakening cold front extends from Nogales, 
Arizona, across the northern Gulf of California and toward the
far northern portion of Baja California Sur. A scatterometer 
satellite pass from 04 UTC indicated 20 to 25 kt W winds in the 
northern Gulf of California along 30N behind the front. These 
winds will likely diminishing through the overnight hours. Expect
strong NW winds over the Gulf of California starting tonight 
through Wed night as high pressure builds in the wake of the cold
front as it sweeps southward across the area. Peak seas are 
likely to reach 5-7 ft in the northern Gulf of California and 
6-8 ft in the central and southern Gulf of California.

Very large NW swell continuing to move into the waters west of 
Baja California today. An altimeter pass from 00 ITCZ indicated 
seas to 14 ft just west of Guadalupe Island. This is peaking
currently, and maximum heights will gradually subside through
late week. Meanwhile, swell in excess of 8 ft will spread 
southward to the Revillagigedo Islands by early Wed, and to Cabo 
Corrientes by ealry Thu. By Fri and Sat another large NW swell 
event of around 12 ft seas should again impact the waters west of
Baja California Norte.

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

Fresh to strong NE gap winds will pulse across the Gulf of 
Papagayo region through the early part of today as high pressure
remains in place over the W Caribbean, then diminish as the high
pressure weakens and shifts east. Peak seas are reaching 8 ft 
through this morning. Elsewhere, winds and seas will be quiescent
through at least Sat night over the Central American and 
equatorial waters. Another round of fresh to strong gap winds is 
possible by late Sat/early Sun in the Papagayo region.

REMAINDER OF THE AREA...

Ridging extends from a 1030 mb high at 30N140W southeastward 
toward Baja California Sur. The pressure gradient between the 
ridge and the ITCZ to the south are producing NE to E fresh to 
strong trades with the strongest winds from 18N to 22N west of 
130W. The trades will increase and become more extensive through 
Wed night as the ridge strengthens. Seas will peak at 10-12 ft 
due to NW swell and NE wind waves. Meanwhile NW swell in excess 
of 8 ft perists across the region north of 05N and west of 110W.

The ridge will weaken Thu and shift east ahead of an approaching
cold front, allowing the NE trades to diminish back to moderate 
to fresh conditions. Maximum wave heights will subside to less
than 12 ft, but the extent of the NW swell of 8 ft or greater
will change little through Fri. While the front will stall near 
30N140W by Thu night into early Fri, reinforcing NW swell will
accompany the front, with wave heights 12 ft or greater covering
the waters northwest of a line from Baja California Norte to
13N140W by Sat night/early Sun. 

$$
Christensen