000
AXPZ20 KNHC 280311
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0311 UTC Wed Dec 28 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 0000 UTC surface analysis and satellite imagery through
0300 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 06N78W to a 1008 mb surface low
near 07N79W to 08N84W to 06N97W. The ITCZ extends from 06N97W to
12N120W. Surface trough extends from 18N119W to 10N122W. The ITCZ
resumes from 10N125W TO 07N140W. Scattered moderate convection
prevails north of 08N between 110W and 126W.

...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 pulse over the
Gulf of California through the next 36 hours. 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...

Surface trough extends from 30N125W to 234N122W to 20N129W. The
pressure gradient between a high pressure centered northwest of
the area and lower pressure south of it is supporting fresh to
strong winds mainly west of the trough. A northwest swell with
seas in the 8 to 11 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 138W.
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 trough will prevail
across the northern portion of the basin. As the area of high
pressure weakens through the week, winds will diminish and seas
will subside. 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