000
AXPZ20 KNHC 161524
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1423 UTC Wed Nov 16 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... 

The pressure gradient between high pressure over eastern Mexico
and low pressure within the monsoon trough over the eastern north
Pacific is supporting gale force winds over the Gulf of Tehuantepec.
Winds over the southwest Gulf of Mexico will veer tonight as the
area of high pressure shifts eastward into the southeast United
States. This will decrease winds flowing through the Chivela pass
with winds expected to diminish below gale force over the Gulf of
Tehuantepec by Thursday. A cold front will move into the Gulf of
Mexico Friday night with strong high pressure building behind it.
This will bring another gale force gap wind event over the Gulf of
Tehuantepec Friday night into this weekend. This will be a
stronger gap wind event with winds expected to reach 45 kt over
the Gulf of Tehuantepec Saturday night.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...  

The monsoon trough extends from 10N86W to 09N96W to 10N108W to
08N116W. The ITCZ extends from 08N116W to 07N121W to 10N137W to
10N140W. Widely scattered moderate convection was noted within 30
nm of the monsoon trough between 101W and 112W. Scattered moderate
convection was noted within 180 nm north of the ITCZ between 130W
and 136W.
  
...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see special features section above for details on the
Gulf of Tehuantepec gale force gap wind event.

Outside of the Gulf of Tehuantepec gap wind event, gentle to
moderate winds with seas in the 5-7 ft range prevail over much of
the open Pacific waters off the coast of Mexico. Seas are 2 ft or
less over the Gulf of California. High pressure building north of
the area will tighten the pressure gradient off the coast of
California and Baja California Norte today. This will strengthen
winds to 25 kt off the coast of Baja California Norte tonight,
with winds reaching gale force off the coast of California. The
gale force winds will help generate another northwesterly swell
which will propagate into the waters off the coast of Baja
California Norte by early Thursday. Seas will peak near 14 ft
early Thursday before starting to subside. By the weekend,
combined seas associated with this swell will subside below 8 ft.
Anther northwesterly swell is forecast to reach the offshore
waters of Baja California Norte early Sunday, with seas building
to near 11 ft by late Sunday night. High pressure building over
the Great Basin region will help increase winds over the northern
waters of the Gulf of California by Thursday morning. With the
progressive pattern over the United States, this area of high
pressure will shift eastward, and winds over the Gulf of
California will diminish below 25 kt by Friday morning. 
  
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...

Moderate to locally fresh northeast winds are expected across and
just downstream of the Gulf of Papagayo late tonight and into
early Thursday morning. Elsewhere, light to gentle northwest to
north winds and combined seas of 3 to 5 ft are expected north of
the monsoon trough, while moderate to fresh southwest flow is
expected to the south of the monsoon trough.

REMAINDER OF THE AREA...

High pressure of 1032 mb is centered north northwest of the area
near 36N141W. The pressure gradient between this strong high
pressure area and lower pressure in the vicinity of the ITCZ is
supporting fresh to strong trade winds north of the ITCZ and west
of 128W as depicted by the latest ASCAT passes. Subsiding
northwest swell continues to propagate through the area with seas
above 8 ft covering the area west of a line from 30N118W to
11N140W. This swell will continue to propagate southeast while
subsiding over the next couple of days. The area of high pressure
will weaken toward weeks end which will help diminish trades over
the western waters. The weakening high pressure will enable a cold
front to move into the NW waters Friday. This front will usher in
yet another set of large NW swells into the area with seas peaking
near 15 ft over the far NW waters Friday night.
      
$$
AL