000
AXPZ20 KNHC 061616
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Thu Oct 6 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
1545 UTC.

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

The monsoon trough axis extends from 14N88W to 13N100W to 14N112W
to 11.5N124W to 12N131W to low pressure near 11N135W 1010 mb to
beyond 11N140W. Scattered moderate isolated strong convection is 
within 120 nm south of the axis between 101W and 105W, between 
125W and 129W, and within 60 nm of the trough axis between 120W
and 125W. Scattered moderate convection is within 60 nm south of
the trough axis west of 137W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

1026 mb high pressure centered north of the area near 37N134W
extends a ridge southeastward to near the Revillagigedo Islands.
The pressure gradient between the ridge and low pressure troughing
over the northern Gulf of California is allowing for moderate to
fresh northwesterly winds to prevail over the waters off the west
coast of Baja California Norte, while light and variable winds
prevail over the Gulf of California and gentle to moderate winds
prevail elsewhere. Seas are in the 6 to 8 ft range off the coast
of Baja California Norte, 1 to 2 ft in the Gulf of California, and
5 to 6 ft elsewhere. The ridge will continue to weaken over the
next couple of days. This will diminish winds over the forecast
area, with light to gentle winds prevailing over much of the
forecast area by this weekend. 

An upper-level anticyclone is centered over southeastern Mexico.
An inverted upper trough is just to the southwest of the anticyclone.
A diffluent flow pattern aloft between the anticyclone and the
trough is helping to maintain a presently active large area of
scattered to numerous showers and thunderstorms north of 14N to
just inland the coast of Mexico from just east of Acapulco west to
near 104W. This activity is likely to continue into Friday. 
Scattered showers and thunderstorms, that occurred during the 
overnight hours are presently weakening within 30 nm of 14.5N95W.

A cold front will move across the Gulf of Mexico on Friday and
Friday night. Building high pressure across the Gulf in the wake
of the front will create a tightening of the pressure gradient
through the Chivela pass beginning late Friday night and into
Saturday morning, with the resultant strong north to northeast
winds of 20 to 25 kt funneling through a narrow swath into the
Gulf of Tehuantepec. Seas will start off at less than 8 ft, then
build to 8 ft early on Saturday. A reinforcing push behind the
cold front is expected late Saturday night into Sunday. This will
increase winds funneling into the Gulf of Tehuantepec to near gale
force, and perhaps even minimal gale force. This upcoming 
gap wind event is expected to continue into the early part of
next week.

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

Light to gentle westerly winds prevail over the waters north of
10N while gentle to moderate southwest to west winds prevail south
of 10N. Seas are in the 4-6 ft range, primarily in long period
southwesterly swell. These conditions are expected to prevail
through Saturday. Wind will become easterly north of 10N on
Sunday as the monsoon trough shifts back southward over the
forecast area.

REMAINDER OF THE AREA... 

The pressure gradient between the aforementioned 1026 mb high
pressure centered north of the area, and lower pressure within
the monsoon trough is supporting an area of moderate to fresh
winds north of the monsoon trough to 20N. These winds are helping
to generate seas in the 6 to 8 ft within this area. Seas are
expected to lower below 8 ft over this area by early Friday
afternoon. Gentle to moderate winds and seas in the 4 to 6 ft
range prevail over the remainder of the waters. The ridge will
weaken over the next several days, bringing a decrease in winds
and seas over the area.
      
$$
AGUIRRE