000
AXPZ20 KNHC 202103
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2103 UTC Mon Jun 20 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 10N78W to 09100W to 08N113W.
The intertropical convergence zone axis extends from 08N113W to
08N121W, then resumes from 08N123W to 05N140W. Scattered moderate
convection is within 240 nm to the south of the monsoon trough and
east of 92W, from 11N to 14N between 101W and 105W, and also from
04N to 07N between 104W and 110W.

A surface trough is embedded in the ITCZ, extending from 14N118W
to 08N122W. Scattered moderate convection is from 12N to 14N
between 117W and 120W.

...DISCUSSION...   

North of 15N east of 120W:

A surface trough extends across the northern Gulf of California
toward Punta Eugenia on the Baja California peninsula. Another
surface trough extends from 32N117W to 20N118W. Gentle to
moderate flow prevails west of the Baja California peninsula
on either side of the trough, with seas of 5 to 7 ft off Baja
California Norte extending to 120W, and 4 to 6 feet elsewhere.
Winds will continue to diminish off Baja California Norte as the
troughing shifts westward. Long period southwest swell will move
to the north of 15N through the early part of the week. Mainly
moderate southerly flow will prevail in the Gulf of California,
occasionally pulsing to fresh to the north of 29N.

The pressure gradient between high pressure building over the
Gulf of Mexico and lower pressures within the monsoon trough over
the eastern North Pacific will help to support strong gap wind
flow through the Gulf of Tehuantepec, commencing tonight. 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 today through the entire week.

South of 15N east of 120W:

Mainly moderate 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, except locally to fresh
downwind of the Gulf of Papagayo. Southwesterly swell is in the 5
to 7 foot range is within 250 nm offshore, and in the 6 to 9 foot
range beyond 250 nm offshore. A new set of long period southwesterly
swell moving into the area will build wave heights to 6 to 9 feet
across the entire area through tonight, then to 7 to 10 feet
Tuesday and Tuesday night through the end of the week. Seas will
finally start to subside Friday and Friday night from south to
north. 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 surge of northerly winds off the coast of Southern California
is pushing south of 32N, and will bring fresh to strong winds as
far south as 24N between 120W and 132W, with seas of 7 to 9 feet
through the early part of the week. These conditions will shift
westward slightly Tuesday and Wednesday, persisting through the
end of the week. Elsewhere 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.

$$
JLewitsky