000
AXPZ20 KNHC 271500
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1243 UTC Tue Dec 27 2016

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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning...High pressure building north
of the area has tightened the gradient across the area. This has
increased winds funneling through the Chivela pass into the Gulf
of Tehuantepec. Winds are currently reaching 25 kt. Winds will
further increase to gale force this evening. The gale force winds
are expected to continue through Friday night. The persistent
gale force winds event will create a plume of 8 to 12 ft seas
extending several hundred miles from shore. Please see latest
National Hurricane Center high seas forecast MIAHSFEP2/FZPN03 KNHC
for further details.

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

The monsoon trough extends from 09N83W to 07N90W to 06N95W. The
ITCZ extends from 06N95W to 09N120W to 06N140W. No significant
convection is noted.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see special features for more on the Gulf of Tehuantepec
gale force wind event. Fresh to strong northwest winds will prevail
over the Gulf of California through the end of the week.
Elsewhere, winds will remain 20 kt or less, with seas below 8 ft
through the end of the week.
  
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...

Winds will pulse over the Gulf of Papagayo the next several
nights. Winds will peak near 25 kt during the overnight hours as
the gap winds are enhanced by nocturnally induced drainage flow.
Winds will decrease to 20 kt during the late afternoon and early
evening hours. Elsewhere, winds will remain 20 kt or less, with
seas below 8 ft through the end of the week.

REMAINDER OF THE AREA...

Weakening low pressure centered near 28N122W and associated cold
front have moved into the northern waters. The pressure gradient
between the low and high pressure centered northwest of the area
near 36N145W is supporting fresh to strong winds northwest of the
low. Northwest swell with seas in the 8 to 12 ft range associated
with this system has propagated into the area. The pressure
gradient between the area of high pressure and lower pressure in
the vicinity of the ITCZ is supporting fresh to strong trades over
the western waters west of 130W. Northwesterly swell is mixing
with northeasterly generated wind waves to produce seas greater
than 8 ft over much of the forecast waters north of 10N and west
of 120W. The low pressure center and associated front will
dissipate by tonight with residual trough lingering over the
northern waters. As the area of high pressure weakens through the
week, winds and seas will decrease. Winds are expected to diminish
below advisory criteria Wednesday night, while the areal extent
of seas 8 ft or greater will continue to decrease through the
weeks end.

$$
AL