000
AXPZ20 KNHC 121025 CCA
TWDEP 

Tropical Weather Discussion...corrected
NWS National Hurricane Center Miami FL
1006 UTC Sat Nov 12 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 0600 UTC surface analysis and satellite imagery through
0945 UTC.

...SPECIAL FEATURES...
A gale warning remains in effect for the Gulf of Tehuantepec. The 
continuation of a tight pressure gradient between a north to
south oriented high pressure ridge over eastern Mexico and
lower pressure over the far SW Gulf of Mexico and far southeastern
Mexico has resulted in another surge of minimal gale force north 
to northeast winds across the Gulf of Tehuantepec within 30 nm
either side of a line from 16N95W to 15N95.5W as was clearly 
depicted on an Ascat pass from last night. These winds will be
short-lived diminishing to 25 to 30 kt around or shortly after 12Z
this morning with seas of 8 to 11 ft. These winds are forecast to
again pulse to minimal gale force this evening, and into late
tonight/early Sunday morning before once again diminishing to 20
to 30 kt around 12Z. Yet another surge of minimal gale force north
to northeast winds is expected across the Gulf Sunday as the 
ridge presses some to the southeast over eastern Mexico. Model
guidance suggests that a more pronounced and longer lived gale
event will occur early next week in response to stronger high
pressure ridging that builds across the Gulf of Mexico and Mexico
in the wake of a cold front.

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

The monsoon trough axis extends from 09N84W to 09N92W to 08N99W
to 12N103W. It resumes from low pressure near 14N110W 1008 mb to 
12N116W to low pressure near 12N124W 1010 mb to 09N129W to low
pressure near 09N138W 1012 mb. Overnight scatterometer data 
indicates that the ITCZ extends from 09N138W west to beyond 
09N140W. Large clusters of scattered strong convection are seen
within 180 nm north of the trough between 96W and 100W. Scattered
moderate to isolated strong convection is within 180 nm south of
the trough between 84W and 90W. Scattered moderate convection is
within 120 nm south of the trough between 113W and 120W, within 60
nm south of the trough east of 81W to the Gulf of Panama, and
also within 60 nm of the trough west of 135W.

...DISCUSSION...corrected   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

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

Gentle to moderate northerly winds are expected across the Gulf of
California with seas generally under 3 ft. Moderate to fresh
northerly winds are forecast across the northern part of the
Gulf, mainly north of 30N Sunday and Monday morning as a result of 
the pressure gradient between a northwest to southeast trough
over western Mexico, and high pressure over the waters to the 
west of the Baja California peninsula.

An extensive batch of large northwest swell will propagates into
the area today through Monday with associated combined seas
forecast to build to 8 to 11 ft over the open waters off the
coast of Baja California. The swell will slowly decay late
Monday into Tuesday with seas lowering to 8 ft. Broad low
pressure system moving into the waters off southwest Mexico is
forecast to increase winds and seas across the offshore waters S
of 20N this weekend. Large clusters of strong convection are
occurring well ahead of this low. This activity is expected to
impact the coasts and portions of interior southwestern and
central Mexico through late Sun. Strong to near gale force east
to southeast winds between 150 nm and 180 nm of the low in the
northeast and southeast quadrants generating seas in the range
of about 9 to 14 ft will approach these same coasts of Mexico
late Saturday and into early Sunday before diminishing later on
Sunday as the low begins to weaken and track in a westward
direction away from Mexico.

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

Winds will pulse the next several days over the Gulf of Papagayo.
Winds will peak near 15 to 20 kt during the late night and early
morning hours, with seas building to 5-6 ft downstream of the Gulf
of Papagayo. Elsewhere, light to gentle winds will prevail over
the waters north of 10N, with gentle to moderate mainly southwest
winds south of 10N. Seas of 4 to 6 ft will prevail across the
region.

REMAINDER OF THE AREA...

A cold front over the northwest portion of the area extends from
near 32N129W to 23N140W. The front is forecast to reach a position
from near 32N127W to 28N131W, and dissipating stationary front to
25N140W by early this evening. A generally weak pressure pattern
to the southeast of the front is allowing for moderate trade
northeast to east winds to exist to the north of the monsoon
trough to within about 120 nm southeast of the front. Once the
front dissipates by Sunday evening, high pressures will build
southeastward across the northwest and north-central waters
through Monday before another cold front moves into the far
northwest corner late on Monday. The broad 1008 mb low pressure
approaching the offshore waters of southwest Mexico is centered
near 14N110W at 06Z moving slowly north-northeast. Scattered
strong convection is well removed from the low due to strong
upper-level winds, and is observed within 60 nm of a line from
13N107W to 17N107W. Scattered moderate isolated strong
convection is within 60 nm of a line from 17N107W to 19N107.5W.
Although some further increase in organization of this system is
possible during the next 12 to 24 hours, even stronger upper-level
winds are likely to preclude tropical cyclone formation as the
low moves north-northeastward. Regardless of tropical cyclone
formation, the aforementioned convection is expected to impact
the coasts and portions of interior southwestern and central
Mexico with locally heavy rainfall during the next couple of
days.

A new set of long period NW swell, with significant wave heights
as high of 12-14 ft is propagating across the NW waters behind
the cold front previously mentioned. This swell will cover the
waters much of the waters N of 10N W of 115W by early Sunday
morning, and much of the waters W of 110W by early Monday morning.
This swell event will continue to propagate southeastward while
subsiding through the middle of next week.

$$
AGUIRRE