000
AXPZ20 KNHC 182110
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2110 UTC Sat Jun 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...         

The monsoon trough axis extends from 09N80W to 06N87W to 08N110W
then resumes from 14N116W to 12N128W. The intertropical
convergence zone axis extends from 12N128W to 09N140W. Scattered
moderate convection is within 180 nm to the south of the monsoon
trough and to the east of 102W, within 210 nm to the north of the
monsoon trough between 88W and 93W, within 270 nm to the north of
the monsoon trough between 96W and 102W, and also from 08N to 11N
to the west of 131W.

...DISCUSSION...   

North of 15N east of 120W:

Weak 1011 mb low pressure in the vicinity of the Revillagigedo
Islands will dissipate by tomorrow. High pressure will build over
the northern waters. This will help tighten the pressure gradient
between the area of high pressure and persistent troughing over
the Gulf of California. Winds will strengthen north of 28N to the
west of the Baja California peninsula starting by early Sunday,
with seas building to near 8 feet. These winds will diminish
Monday as the trough shifts westward off the coast of the Baja
California peninsula. Long period southwest swell start to move
north of 15N early next week. The pressure gradient between high
pressure building over the Gulf of Mexico and the monsoon trough
over the eastern North Pacific will help for strong gap wind flow
into the Gulf of Tehuantepec. The mix of shorter period wind waves
from the gap winds and the longer period southwest swell will
result in areas of confused seas in and downstream of the Gulf of
Tehuantepec. In addition, the swell will allow the potential for
hazardous surf along exposed areas of the coast of Mexico starting
late Monday through mid week.

South of 15N east of 120W:

Moderate to locally Fresh monsoonal flow prevails to the south of
the monsoon trough. Gentle to moderate northeasterly trade winds
prevail to the north of the monsoon trough. Subsiding southwesterly
swell continues to propagate across the area with seas in the 5 to
6 foot range from 100W westward, and in the 3 to 5 foot range from
100W eastward. A fresh set of long period southwesterly swell will
move into the area starting late Sunday. Wave heights will build
to 6 to 9 ft on Tuesday, and then to 7 to 10 feet by Thursday.
This swell will reach the coast of Central America by mid week
creating the potential for hazardous surf along exposed areas of
the coast.

West of 120W:

A surface trough, the remnants of a dissipated cold front, reaches
from 30N127W to 25N140W. This trough will drift westward tonight
as high pressure continues to build across the region to the north
of 25N. The pressure gradient between this area of high pressure
and low pressure in the monsoon trough and in the vicinity of the
ITCZ is supporting moderate to fresh winds with seas in the 4 to 7
foot range. The ridge will prevail in the northern waters during
the next few days with these general conditions persisting. A
surge of northerly winds off the coast of Southern California will
push south of 32N by Monday, bringing fresh to strong winds as far
south as 28N between 120W and 126W with seas to 8 ft by early next
week. These conditions will shift westward slightly Tuesday and
Wednesday, diminishing thereafter.

$$
JLewitsky