000
AXPZ20 KNHC 180226
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sat Mar 18 2017

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.

...SPECIAL FEATURES...

A gale warning is expected to remain in effect for the Gulf of 
Tehuantepec through Monday. At 2100 UTC, a ship call-sign PINX
located near 15.5N96W reported 36 kt winds from the NE. Very 
strong winds and high seas will persist several more days as high
pressure northeast of the area in the northern Gulf of Mexico 
enhances drainage flow from the Gulf of Mexico across the Isthmus
of Tehuantepec into the eastern Pacific Ocean. Winds are likely 
to increase to 40 kt Saturday night through Monday morning with
seas building up to 15 ft. Then, winds are forecast to diminish 
below gale force Monday night and Tuesday. Northerly swell 
generated by this gap wind event will propagate southward and mix
with swell generated in the Gulf of Papagayo. This will result 
in combined seas of up to 9 ft in waters from 05N to 12N between 
90W and 105W on Saturday, and between 90W and 112W on Sunday.

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

The Intertropical Convergence Zone remains south of the Equator.
A trough axis extends from 06N90W to 04N95W to 01N100W. Isolated
moderate convection is noted within about 90 nm either side of
the trough axis.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

See the Special Features section for information on the Gulf of 
Tehuantepec gap wind event. 

High pressure of 1018 mb centered near 28N125W will shift SE 
through Saturday. A ridge extending southeast from the high to 
the Revillagigedo Islands will persist through the weekend. 
Gentle to moderate NW winds and 4 to 5 ft seas are expected to 
continue the next couple of days. A weakening cold front is 
expected to push into northern Baja California Tuesday night and 
extend across the southern Gulf of California and southern Baja 
California by Wednesday night.

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

Again, high pressure over the NW Caribbean and Gulf of Mexico 
will support a fresh to strong gap wind event across the Gulfs 
of Papagayo and Fonseca late tonight into Saturday morning. The 
gap wind event in the Gulf of Papagayo will persist into early 
next week. Fresh N-NE winds are also forecast across the Gulf of 
Panama and downwind to about 05N at night. Seas will build to 5-7
ft in this area, including offshore of the Azuero Peninsula 
through Sunday night. Otherwise, light to gentle winds and 
combined seas of 3-5 ft are expected to continue the next several
days.

REMAINDER OF THE AREA...

High pressure of 1018 mb near 28N125W will shift SE over the 
next 24 hours, ahead of a cold front currently moving across the 
far NW corner of the forecast area. Fresh to strong SW flow 
ahead of the front is expected to continue over far northwest 
forecast waters through tonight. The front will stall and weaken 
from 30N132W to 26N137W to 25N140W Saturday night. A low pressure 
is forecast to form along the frontal boundary early on Sunday.
The low will move NE dragging the cold front across the north
waters on Monday. At the same time, a new cold front will reach
the far NW waters. This second push of cold air will overtake 
the first front Tuesday. Fresh winds are expected on either side 
of the merging front as it pushes westward into nothern Baja 
California on Wednesday. Moderate to locally fresh trades will 
persist elsewhere across the tropical Pacific with combined seas 
of 5-7 ft through Sunday.

$$
GR