Tropical Weather Discussion
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AXPZ20 KNHC 211551

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Fri Oct 21 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.


Gulf of Tehuantepec gale warning...The latest guidance suggests
that the current minimal gale force winds will increase to 30 to
40 kt in about 12 hours, then diminish to 30 to 35 kt on Sat and
continue into the early morning hours on Sun before diminishing
below gale force by late sun morning. Minimal gale force
conditions are expected to develop again late Mon and
continue through Tue night.

A 1006 mb stationary surface low is embedded in the monsoon
trough near 13N115W with scattered moderate isolated strong
convection currently observed within 180 nm over the s quadrant
of the low. This low has the potential to become a tropical
cyclone over the next few days, then increasing wind shear
should inhibit development.


The monsoon trough extends off the Pacific coast of Nicaragua
along 12N87W to 14N112W to low pres near 13N115W to low pres
10N131W to beyond 14N114W. Scattered moderate isolated strong
convection is observed within 125 nm w of the surface low at
13N131W, elsewhere within 150 nm either side of a line from
12N87W to 11N108W and within 90 nm either side of a line from
13N117W to 10N123W.

Scattered moderate and isolated strong convection is observed
along the Pacific coast of Colombia within 90 nm of 06N78W,
and over the Pacific coast of Mexico and extending offshore
within 75 nm either side of a line from 18N103W to 15N109W.



See special features for Gulf of Tehuantepec. A sub-tropical
ridge axis extends from nw to se across the offshore zones w of
central Mexico. Light to gentle nw flow with combined seas of 5
to 7 ft are expected through Sat night. Seas are forecast to
then build to 7 to 9 ft across the waters n of 30N w of 117W on
Sat night, and continue through Sun.

Moderate to fresh nw winds across the northern Gulf of
California will diminish this afternoon. Light and variable
winds are expected elsewhere through early Sat, then light
southerly flow expected across the entire gulf waters late Sat
except increasing to moderate s winds across the northern gulf
waters on Sat night and Sun.

Light and variable winds expected elsewhere within 250 nm of the
Mexican coast n of the Gulf of Tehuantepec through Sat, except
moderate e to se winds are forecast beyond 200 nm on Sun and


Gentle w to nw winds are expected through Sat n of  the monsoon
trough which is meandering e to w along about 10N, while
moderate sw flow is expected s of the monsoon trough Sat. The
pressure gradient will relax on Sat night as the monsoon trough
shifts s and extends from e to w along 07N. Combined seas of 4
to 7 ft, primarily in long-period sw swell is expected across
the offshore waters for the next 3 to 5 days.


A ridge extends from 32N140W to 17N110W. Moderate to fresh ne
trades and 6 to 8 ft seas are expected through tonight s of the
ridge and n of the relatively lower pressure within the monsoon
trough. Winds and seas will continue to gradually diminish
across the waters s of the ridge over the next couple of days.
Nw swell is forecast to propagate e across the waters n of the
ridge through Sat driving seas heights to 7 to 9 ft.

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