AXPZ20 KNHC 222151

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.


A 1007 mb surface low remains embedded in the monsoon trough near
12N100.5W. Showers and thunderstorms continue to show signs of
organization in association with this area of low pressure. Latest
satellite imagery shows scattered moderate convection within about
90 nm W semicircle of low. Similar convection is noted just N of
low center from 12N-15N between 99W-105W. Environmental conditions
are expected to be conducive for development during the next few
days, and a tropical depression will likely form by Monday while
the system moves west-northwestward at about 10 kt. The latest
Tropical Weather Outlook gives this system a high chance of
tropical cyclone formation through 48 hours.

A gale warning remains in effect for the Gulf of Tehuantepec.
Minimal gale force winds are expected tonight into early Sun
morning, then winds will diminish to 20-30 kt during the day.
Northerly winds will continue to surge across the Tehuantepec
area, increasing again to 30 to 35 kt Mon night into early Tue
morning, and Tue night into early Wed morning with the assistance
of the nocturnal drainage flow. Seas are forecast to build to
10-11 ft with the strongest winds.


The monsoon trough extends from 10N86W to 12N94W to 1007 mb low
pressure near 12N100.5W to 1007 mb low pres near 13.5N115.5W to
11N122W to 1009 mb low pres near 10N129.5W to beyond 12N140W.
Scattered moderate isolated strong convection is noted from 10N to
14N between 118W and 121W. Scattered moderate convection is near
13N95.5W and from 04.5N to 06.5N between 82W AND 84W.



See special features for the Gulf of Tehuantepec area. 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 waters of 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, mainly gentle southerly winds are
noted based on scatterometer and surface data. This general wind
direction will persist on Sun, then light and variable winds are
expected on Mon.

Light and variable winds are also 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.


Gulf of Papagayo: fresh to locally strong NE winds are expected
across and just downstream of the Gulf of Papagayo Sun morning and
Monday morning. Gentle to moderate S to SW winds are noted per
scatterometer data S of 05N, while gentle to moderate W to NW
winds are N of 05N. Combined seas of 4 to 6 ft, primarily in
long-period SW swell dominate the offshore waters. These marine
conditions will persist over the few days.


A ridge dominates most of the north waters N of 15N W of 115W.
This system is producing mainly gentle to moderate trade winds.
Winds increase to 15-20 kt near the monsoon trough due to the
presence of three low pres systems.

A cold front is dissipating near 30N140W. A new pulse of long
period NW swell is moving out ahead of the front. This swell event
will continue to propagate SE across the NW waters tonight 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.