AXPZ20 KNHC 221008

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
203 UTC Sat Oct 22 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
0900 UTC.

A gale warning remains in effect for the Gulf of Tehuantepec.
The latest computer model guidance suggests that winds have
likely increased to 30 to 40 kt already tonight, and will
diminish shortly to 30 to 35 kt before sunrise and persist to
near noon today before falling into the 25-30 kt range through
this evening. A high pressure ridge across eastern Mexico
behind a Gulf of Mexico cold front will prevail for the next few
days and maintain strong northerly winds across the Gulf of
Tehuantepec that will increase to at or just below gale force
each late night through early morning through at least Tue.

Clusters of moderate to strong convection noted 300-450 nm
southwest of the Gulf of Tehuantepec are associated with a broad
area of low pressure located near 10.5N99.5W. Satellite imagery
indicates clusters of moderate to strong convection within about
270 nm across the NW quadrant of the low, while scattered
moderate to strong convection is elsewhere from 08N to 13N
between 95W and 103W. Environmental conditions are expected to
be conducive for development of this disturbance over the next
few days, and a tropical depression may form early next week
while the system moves toward the west-northwest at about 10 kt.

The monsoon trough extends from 13.5N88W to low pres near
10.5N99.5W to 14N112.5W to low pres near 13.5N115.5W to low pres
near 10.5N128.5W to beyond 12.5N140W. Scattered moderate to
strongconvection is noted from 02.5N to 07N between 77W and 82W.
Scattered moderate to strong convection is noted within 120 nm N
and 180 nm S of trough between 121W and 132W. from 08N to 11.5N
between 120W AND 129W.


Northerly gap wind flow across the Gulf of Tehuantepec is
expected to persist throughout most of the upcoming week.
Elsewhere, a sub-tropical ridge axis extends from NW to SE
across the offshore waters of Baja California Sur near 22N115W.
Light to gentle NW winds are expected across the Pacific
watersof baja California through Sunday before weak troughing
develop just offshore of Baja California Sur to produce light
and variable winds. Combined seas of 4 to 6 ft in NW swell are
expected through early Sun before seas build to 5-8 ft Sun
through Mon in a new pulse of NW swell.

Inside the Gulf of California, Gentle to moderate NW winds this
morning are forecast to become light and variable today, then
light southerly flow is expected across the entire gulf waters
late Sat and Sun.

Light and variable winds are expected elsewhere within 250 nm of
the Mexican coast W of the Gulf of Tehuantepec through Sun,
except moderate E to SE winds are expected across the outer
waters between Acapulco and Cabo Corrientes due to the current
low pres SW of Tehuantepec moving across the area.

Gentle to moderate W to SW winds are noted per overnight
scatterometer data S of 06N, while gentle to moderate W to NW
winds are N of 06N. Combined seas of 4 to 7 ft, primarily in
long-period SW swell are expected across the offshore waters for
the next 3 to 5 days.

A ridge dominates most of the north waters N of 15N W of 115W. The
pres gradient between the ridge and lower pres in the vicinity of
the monsoon trough is resulting in an area of moderate to fresh
winds between 14N and 20N W of 120W based on overnight
scatterometer data. Seas in this area are 6-8 ft and not
expected to fluctuate much through Sun. A cold front is
expected to approach 30N140W tonight while gradually dissipating
through late Saturday. A new pulse of long period NW swell will
move out ahead of the front and propagate SE across the NW
waters Sat and Sun, reaching the waters W of Baja on Sun.
Another cold front will be near 30N140W on Monday and will be
reinforcing by a second cold front reaching the same area on
Tue. The merging cold front is forecast to extend from 30N135W
to beyond 27N140W by late Tue.