000
AXPZ20 KNHC 190225
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0210 UTC Sun Jun 19 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 0000 UTC surface analysis and satellite imagery through
0200 UTC.

..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...         

The monsoon trough axis extends from 08N81W to 10N89W to low
pressure near 08N106W, then resumes from 15N115W to 12N120W. The
intertropical convergence zone axis extends from 12N120W to beyond
09N140W. Scattered moderate convection is from 04N to 07N between
91W and 103W, from 11N to 13N between 121W and 127W, and also from
08N to 10N to the west of 137W.

...DISCUSSION...   

North of 15N east of 120W:

Weak low pressure that was in the vicinity of the Revillagigedo
Islands has dissipated into an open trough, while high pressure
builds over the northern waters. The pressure gradient will
tighten between the 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 beyond 250 nm offshore, and in the 3 to 5 foot range
within 250 nm offshore. 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 Monday and Tuesday, and then to 7 to
10 feet Wednesday and 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 30N128W to 27N138W. This trough will drift westward during
the overnight hours 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 vicinity of the 
monsoon trough and 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