000
AXPZ20 KNHC 181538
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1530 UTC Tue Oct 18 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
1515 UTC.

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

Surface troughing extends from the Nicaragua Coast near 12N86W to
13N99W. The monsoon trough extends from 14N108W through a 1010 mb
low pressure near 10N113W to a 1008 mb low pressure near 14N133W
to 10N139W. Numerous moderate and isolated strong convection are
from 08N to 16N E of 97W. Scattered moderate and isolated strong
convection are from 08N to 13N between 97W and 119W, and from 11N
to 17N between 126W and 136W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A high pressure ridge extends SE from a 1024 mb surface high
pressure center near 34N135W to near the Revillagigedo Islands at
17N110W. Moderate to fresh NW winds prevail west of Baja
California. The combination of these winds and long period NW
swell support seas of 8 to 10 ft W of Baja California Norte, and 6
to 8 ft W of Baja California Sur. The high pressure center will
shift NE through the week and the ridge will weaken later this
week as a cold front approaches the region. Winds will therefore
gradually lessen over this area through the week, becoming light
to moderate by Thursday and Friday. The long period swell will
subside over the next few days. A new batch of swell of 8 to 9 ft
is forecast to arrive offshore Baja California Norte over the
weekend.

Fresh N winds will pulse over the Gulf of Tehuantepec each night
through Wednesday night. A strong area of high pressure behind a
cold front over the Gulf of Mexico will support fresh to strong N
to NE Tehuantepec gap winds Thursday night, then Gale force winds
Friday through Monday. Model guidance suggests that winds could
reach strong gale force Friday night through Sunday.

Elsewhere, light to gentle winds prevail. Surface troughing over
the Baja peninsula continues to promote a light wind regime over
the Gulf of California with seas generally 2 ft or less. Seas of 
around 4-6 ft prevail elsewhere. Fresh to strong winds are
expected to develop over the Gulf of California N of 26N Wednesday
night through Thursday night as the pressure gradient tightens
between the high pressure ridge W of Baja and low pressure over
Arizona. These winds will support seas up to 5 ft.

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

Moderate to fresh SW winds are evident S of surface troughing
along 11-12N. Mainly light to gentle winds continue N of this
troughing. Seas are in the 4-6 ft range N of 11N in a mix of NW
and SW swell. Seas of 5-7 ft are S of 11N in primarily SW swell.
These conditions are forecast to prevail through Friday. Numerous
showers and thunderstorms persist within 250 nm of the coast of
Central America N of 08N. This convection will likely continue
through Wednesday, producing very heavy rainfall over the coastal
sections.

REMAINDER OF THE AREA... 

1008 mb low pressure is centered near 14N133W. This system has a
low potential to become a tropical cyclone during the next few
days as it moves W to WSW. The pressure gradient between the high
pressure ridge NW of the Revillagigedo Islands and this low is
generating fresh to strong winds in the NW semicircle within 360
nm of the low, with seas of 9-11 ft. Elsewhere, moderate to fresh
winds will prevail between the monsoon trough and the ridge the
next couple of days...except light and variable winds along the
ridge axis. Large long period NW swell has been affecting the area
the last few days. Combined seas greater than 8 ft covers the area
N of 10N and W of 113W. The combined seas greater than 8 ft will
continue into the middle of the week, then diminish below 8 ft
over the majority of the area late this week. Elsewhere, the
combination of SW winds S of the monsoon trough and NW swell will
support seas of 8-10 ft mainly from 03N and 12N between 96W and
125W through Saturday. Cross-equatorial SW swell of 8-9 ft will
propagate NE between 95W and 115W and cause seas S of 02N to build
to between 8 and 9 ft today through Thursday, then seas in this
area will subside below 8 ft late this week.

$$
LATTO
NATIONAL HURRICANE CENTER