000
AXPZ20 KNHC 310948
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
910 UTC Tue Jan 31 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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: Strong gales continue through
the Gulf of Tehuantepec this morning with associated seas to 16
ft. The gale force winds are expected to persist through sunrise
on Tue then diminish. The associated north to northeast swell 
will mix with both long period southwesterly cross- equatorial 
swell, and long period northwesterly swell, resulting in a large 
area of combined seas of 8 ft or greater reaching the equator 
between 95W and 105W before beginning to subside. Looking ahead,
minimal gale forces winds are possible on Thu and Fri nights. 

Eastern Pacific Gale Warning: Southerly winds to gale force
precede a cold front reaching from 30N136W to 21N140W. The
combination of the strong winds and a component of longer period
northwest swell is resulting in seas to 16 ft follow the front, 
as noted in a recent altimeter pass. A few showers may be active
along and ahead of the front north of 28N. Winds will subside
below gale force in the next several hours, but another round of
winds to gale force is likely behind the front starting today and
persisting through early Tuesday, as the front reaches a position
from 30N130W to 19N140W. The front will make slow progress
eastward, eventually reaching a position from 30N125W to 19N135W
as it starts to weaken. Strong winds will follow the front
through mid week north of 27N, but decrease in coverage. The
northwest swell will continue to propagate into the region, with
seas reaching as high as 20 ft near 30N140W by this afternoon.
The swell will decay gradually, but lingering combined seas of 
12 to 15 ft will still be likely from 27N to 30N between 130W 
and 140W by late week.

See the latest NWS High Seas Forecast under AWIPS/WMO headers 
MIAHSFEP2/FZPN03 KNHC for additional details on these warnings.

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

A surface trough extends from 06N89W to 02N93W to 03N102W. The
ITCZ reaches from 10N125W to 09N140W. Scattered moderate
convection is ongoing within 120 nm north of the ITCZ between
130W and 135W. 

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

See special features section above for gale conditions in and 
downstream of the Gulf of Tehuantepec.

Weak high pressure north of the region is supporting gentle to
moderate breezes across area, to include the Gulf of California.
Seas are mostly 3 to 5 ft in open waters. Winds and seas diminish
further through mid week as the high pressure builds over the
region. Looking ahead, a new round of northwest swell will move 
into the waters off Baja California Norte by late Thursday with 
seas 4 to 6 ft, building to 8 ft near Guadalupe Island by late 
Friday.

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

Gulfs of Papagayo and Fonseca: Pulsing strong east-northeast 
winds are expected across the offshore waters from roughly 09N to
12.5N this week, with the maximum seas building to 10 ft near 
09N90W. The resultant northeast swell will merge on Tue and Wed 
with the northwest swell from the strong gap event in the Gulf 
of Tehuantepec. 

Gulf of Panama: A 60 nm wide band of fresh to locally strong n
winds from the western Gulf of Panama to 03N81W are expected
through late Tue, with seas building to 8 ft.

Light to gentle winds, and combined seas of 3 to 5 ft, are 
occurring elsewhere outside of the swells originating near the 
gap events. 

REMAINDER OF THE AREA... 

Aside from the EPAC gale associated with a cold front mentioned 
in the Special Features section above, an earlier pulse of 
northwest swell in the form of 7 to 10 ft seas are still 
observed west of 130W. The post frontal swell will propagate se 
across the open Pacific waters, merge with the current swell, 
and reach along 115W late this week.
 
$$
Christensen