000
AXPZ20 KNHC 111554
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1404 UTC Tue Oct 11 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...

A gale warning remains in effect for the Gulf of Tehuantepec.
Winds in this area are in the 30-40 kt range based on a pair of
ship observations and an earlier Ascat pass. A tight pressure
gradient continues between 1020 mb high pressure centered over
east-central Mexico and a 1008 mb surface low located in the
eastern Pacific near 11N100W. This is resulting in ongoing gap
wind event. The high pressure will weaken slightly and the low
pressure to the south will continue to move westward, allowing the
pres gradient to weaken and winds to diminish slightly. However...
strong gap winds will continue through Friday, mainly during the
overnight and early morning hours when winds may reach 30 kt. Seas
are forecast to build to 10-11 ft with these winds.

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

The monsoon trough extends from 07.5N78W to 10N87W to 13N94W to
1008 mb low pres near 11N100W to 14N115W to 1008 mb low pres near
10n128w to 08N140W. Scattered moderate convection is noted within
30 nm either side of axis E of 86W, and from 11N to 14N between
90W and 97W. Scattered moderate to isolated strong convection is
from 12N to 15N between 112W and 116W, and from 11N to 14N between
122W and 128W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A weak 1018 mb high pressure located near 31N130W extends a ridge
SE across the Pacific waters of Baja California peninsula,
producing mainly light to gentle NW-N winds with seas of 4-6 ft.
As the subtropical ridge strengthens...expect increasing winds
to 15-20 kt and building seas to around 7 ft off the coast of the
Baja California peninsula by Wednesday. Elsewhere light to gentle
winds, and 3 to 5 ft seas will persist. 

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

Gentle to moderate southwest winds persist south of the monsoon
through...including the waters between Ecuador and the Galapagos
Islands. Seas are 4 to 6 ft south of the monsoon trough largely
associated with long period southwest swell. These marine
conditions will change little over the next few days. 

Scatterometer data indicate moderate to fresh NE winds across the
Gulf of Papagayo. This weather pattern will persist over the next
2-3 days.

REMAINDER OF THE AREA... 

As previously mentioned...a weak 1018 mb high pressure located
near 31N130W extends a ridge SE across the north waters to near
the Revillagigedo Islands. The ridge is forecast to slightly
strengthen on Wednesday. A frontal trough is analyzed across the
NW waters and extends from 30N135W to 24N140W. A 75-90 nm wide 
band of mainly low clouds is still noted is association with this
trough forecast to gradually dissipate by late Wednesday. Seas to
9 ft in NW swell are noted per an altimeter pass in the wake of
the frontal trough. Another set of NW swell should reach the far
NW portion on Wednesday. This swell event will dominate the waters
NW of a line from 30N133W to 20N138W by early Thursday morning
with seas building to near 12 ft.

An area of moderate to fresh trade winds persists between the
ridge to the north and a 1007 mb low pressure located near
16N121W covering roughly the region from 12N to 21N between 118W
and 127W. These winds are expected to persist over the next 48
hours as the low pressure continues to move west-northwestward.
Showers and thunderstorms associated with this feature have
become a little more concentrated this morning. A cluster of
moderate to isolated strong convection is noted within about 150
nm NW quadrant of low center. This disturbance has the potential
to become a tropical depression before it moves over cooler waters
in 2 or 3 days.

Another low pressure area is noted downstream from the Gulf of
Tehuantepec near 11N100W. Disorganized showers and thunderstorms 
are associated with this weak low pressure system. Environmental
conditions are expected to be generally conducive for development,
and a tropical depression could form by the weekend while the low
moves westward well to the southwest of mainland Mexico. An area
of fresh to strong winds is observed is association with this low 
from 11N to 13N between 97.5W and 102W with seas of 8 to 10 ft.
Scattered moderate to isolated strong convection is to the N of
the low center from 12N to 15.5N between 98W and 105W.

$$
GR