000
AXPZ20 KNHC 172120
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Fri Mar 17 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

A gale warning is expected to remain in effect for the Gulf of 
Tehuantepec through Monday night. Model guidance shows maximum 
winds dipping slightly below gale force this evening and again 
Saturday evening between 1800 and 0300 UTC but 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. 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 93W and 109W this weekend.

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

The Intertropical Convergence Zone remains south of the Equator.
A trough axis extends from 07N86W to 01N99W. Scattered moderate 
and isolated strong convection is noted from 03N to 07N between 
88W and 98W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

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

High pressure centered near 31N126W will weaken and shift 
southward 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...

High pressure over the NW Caribbean and Gulf of Mexico produced 
a fresh to strong gap wind event across the Gulf of Papagayo and 
Gulf of Fonseca this morning. The most recent scatterometer data
provided observations of 25 kt NE winds downstream from the Gulfs
of Papagayo and Fonseca. 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 Saturday 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 1020 mb near 31N126W will shift SE over the next
24 hours, ahead of a cold front currently reaching 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
24N140W Saturday night. A second push of cold air will overtake 
the first front Tuesday. Fresh winds are expected on either side 
of the combined front as it pushes westward into Baja California.
Moderate to locally fresh trades will persist elsewhere across 
the tropical Pacific with combined seas of 5-7 ft through Sunday.

$$
GR