000
AXPZ20 KNHC 272136
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1952 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 1800 UTC surface analysis and satellite imagery through
2130 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning...High pressure building north
of the area has tightened the gradient increasing the winds
funneling through the Chivela pass into the Gulf of Tehuantepec.
Winds are currently ranging between 15 to 25 kt. Winds are
expected to reach gale force tonight and continue pulsing though
the next 48 hours. These winds will generate 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 06N77W to a 1008 mb surface low
near 06N79W to 09N85W to 06N95W. The ITCZ extends from 06N95W TO
09N117W. Surface trough extends from 13N119W to 09N122W. The ITCZ
resumes from 08N125W TO 06N140W. Scattered moderate convection
prevails between 110W and 130W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see special features for more on the Gulf of Tehuantepec
gale-force wind event. Fresh 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, peaking to 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 28N125W and associated
frontal system analyzed as an occluded front from the low to
27N121W then as a dissipating stationary front from that point
to 21N129W. The pressure gradient between this low and a high
pressure centered northwest of the area near 36N142W is supporting
fresh to strong winds mainly northwest of the low. A northwest
swell with seas in the 8 to 12 ft range are associated with this
system. The pressure gradient between the area of high pressure
discussed above and lower pressure in the vicinity of the ITCZ is
supporting fresh to strong trades over the western waters west of
132W. 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 weekend.

$$

NATIONAL HURRICANE CENTER