000
AXPZ20 KNHC 150308
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Tue Dec 15 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 0000 UTC surface analysis and satellite imagery through
0300 UTC.

...SPECIAL FEATURES...

Gulf of Tehunatepec Gale Warning: High pressure building
southward along the eastern slopes of the Sierra Madre Oriental
and across the Gulf of Mexico behind a cold front will support 
brief gales in the Tehuantepec region tonight. Gale force winds
to 40 kt are expected in this region, with seas building up to 
12 or 13 ft. Winds will quickly diminish well below gale-force 
by early Tue morning. A second gap wind event is expected in the 
Tehuantepec area Wed night through Thu night as another cold 
front moves across the Gulf of Mexico. Marine guidance suggests 
minimal gale-force winds and building seas of up to 12-13 ft 
with this second gale event. Please, read the latest NWS High 
Seas Forecast issued by the National Hurricane Center at website 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml.

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

The monsoon trough extends from a 1009 mb low pressure over 
northern Colombia near 10N74W to 05N80W to 07N95W to 07N110W. 
The ITCZ continues from 07N110W to 08N125W to beyond 07N140W. 
Scattered moderate convection is noted from 06N to 08N between 
98W and 102W, from 08N to 10N between 116W and 120W. Similar
convection is seen near 13N108W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

A Gale Warning remains in effect for the Tehuantepec region. 
Please, see the Special Features section for more details.

A ridge dominates the offshore forecast waters of Baja California.
The pressure gradient between the ridge and lower pressures over
mainland Mexico supports fresh to locally strong NW winds N of
28N E of 121W. Long period NW swell is currently propagating 
across the waters N of Cabo San Lazaro with seas building up to
12-13 ft. This swell event will reach the Revillagigedo Islands
on Tue. 

Gulf of California: Mainly moderate to fresh NW-N winds will
prevail in the Gulf of California during the forecast period with
the exception of fresh to locally strong winds on Wed. Seas will
remain under 8 ft.

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

Moderate to fresh NE-E winds will prevail in the Papagayo region
over the next several days with seas of 4-6 ft. Winds are expected
to increase to fresh to strong Thu night through Sat night as high
pressure builds over the western Caribbean. Gentle to moderate 
northerly winds are expected in the Gulf of Panama with sea heights
of 3-5 ft. Elsewhere, gentle to moderate winds will prevail S of
the monsoon trough with mainly gentle winds N of it. Seas will
continue to subside to 4-6 ft between Ecuador and the Galapagos 
Islands by tonight.

REMAINDER OF THE AREA...

High pressure of 1028 mb located near 34N129W extends a ridge SE
across the northern forecast waters to near the Revillagigedo 
Islands. The pressure gradient between the ridge and lower 
pressures in the vicinity of the ITCZ is supporting a large area 
of fresh to locally strong trade winds from 11N to 21N W of 125W
These winds will persist over the next 48 hours as high pressure
remains in place. 

Long period NW swell dominate most of the waters N of 10N and W 
of 115W this evening. Seas are forecast to build to 10-13 ft 
over the NE waters W of Baja California norte. Additional pulses
of NW swell will reach 30N140W on Tue. 

$$
GR