000
AXPZ20 KNHC 192117
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2108 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...         

The monsoon trough axis extends from low pressure located over
western Colombia near 06N77W to 10N90W to 07N105W to 11N115W to
10N120W. The intertropical convergence zone axis extends from
10N120W to 07N126W to 08N140W. Scattered moderate convection is
within 240 nm to the south of the monsoon trough axis to the east
of 92W, and also within 60 nm either side of the axis between 97W
and 103W.

...DISCUSSION...   

North of 15N east of 120W:

High pressure ridging prevails over the northern portion to the
west of the Baja California peninsula. A surface trough prevails
over the Baja California peninsula. The pressure gradient between
these two features is supporting moderate to fresh northwesterly
winds over the waters to the west of Baja California Norte out to
120W. Gentle to moderate winds prevail elsewhere. Northwest winds
will continue to increase off the coast of Baja California Norte,
reaching fresh to strong to the north of 28N by late tonight.
These winds will diminish Monday as the trough shifts westward off
the coast of the Baja California peninsula. Long period southwest
swell will move to the north of 15N through the early part of the
week. The pressure gradient between high pressure building over
the Gulf of Mexico and lower pressures with the monsoon trough
over the eastern North Pacific will help to support strong gap
wind flow through the Gulf of Tehuantepec, commencing Monday
afternoon. The mix of shorter period wind waves from the gap winds
with 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 bring the potential for hazardous surf
along exposed areas of the coast of Mexico starting late Monday
through the entire week.

South of 15N east of 120W:

Moderate to locally fresh monsoonal flow prevails to the south of
the monsoon trough, while gentle to moderate northeasterly trade
winds prevail to the north of the monsoon trough. Southwesterly
swell in the 3 to 5 foot range within 250 nm offshore, and in the
6 to 9 foot range beyond 250 nm offshore as a new set of long
period southwesterly swell moves into the area. Wave heights will
build to 6 to 9 feet across the entire area Monday and Monday
night, then to 7 to 10 feet Tuesday and Tuesday night through the
end of the week, finally starting to decay Friday and Friday
night. 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:

The pressure gradient between high pressure anchored to the north
of the region, and low pressure within the monsoon trough and in
the vicinity of the ITCZ is supporting moderate to fresh winds,
with combined seas in the 4 to 7 foot range, except up to 8 feet
near the Equator. 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 127W, with seas to 8 ft
through the early part of the week. These conditions will shift
westward slightly Tuesday and Wednesday, persisting through the
end of the week.

$$
JLewitsky