000
AXPZ20 KNHC 152132
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2026 UTC Fri Dec 15 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...

Gulf of Tehuantepec Gale Warning: A cold front moving southward 
across the western Gulf of Mexico will reach the Isthmus of 
Tehuantepec tonight. Cool and dense air will funnel through the 
Chivela pass into the Gulf of Tehuantepec this evening with winds
rapidly ramping up to near gale force and further to gale force 
later tonight. The front will weaken Saturday, which will 
diminish winds funneling across the Gulf of Tehuantepec. This 
will keep this gale force gap wind event brief as winds are 
expected to diminish below gale force by Sat afternoon. 

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

The ITCZ extends from 09N84W to 06N96W to 07N104W to 07N118W to
10N130W to 10N140W. No significant convection is observed near 
the ITCZ, but scattered moderate convection is noted from 15N to
18N between 105W and 112W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gulf of California: Strong high pressure north of the area over
the Great Basin and northern Rockies is supporting fresh to
occasionally strong NW winds over the far northern Gulf of 
California. A cold front will move into the northern Gulf Sat, 
before stalling and dissipating over the central Gulf Sun. Winds 
over the northern Gulf will shift SW early Sat ahead of the 
front, as associated low pressure deepens over the lower Colorado
River basin. The main issue by Sat night will be the possibility
of strong W to NW winds over the northern Gulf as the low 
pressure shifts eastward into the Sonora Desert. While the fetch
across the northern Gulf will be to limited to develop large 
seas, mariners should be aware of the possibility of sudden 
strong winds through low lying areas of Baja California Norte 
through early Sun. Winds diminish through early next week after 
the low pressure dissipates.

A cold front will move through the waters off Baja California 
Norte through early Sat followed by strong NW winds and seas 
building to 8 to 12 ft by late Sat. Seas of 8 to 10 ft will cover
most of the waters beyond 60 nm of the Baja coast through early 
next week in NW swell. Elsewhere gentle to moderate winds and 3 
to 5 ft will persist along the coast of Mexico outside of the 
Gulf of Tehuantepec through mid week.

Please see Special Features section for more information on the
latest Gulf of Tehuantepec gale warning. Another gale force gap 
wind event is possible over the Gulf of Tehuantepec on 
Wednesday.

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

Winds are expected to strengthen across the Gulf of 
Papagayo Sat night. Fresh N winds will funnel into the Gulf of 
Panama through late this morning. 

REMAINDER OF THE AREA...

Fresh to strong tradewinds prevail from 15N to 22N west of 133W.
Moderate to fresh winds prevails elsewhere over the forecast 
waters north of the ITCZ to 20N and west of 120W. Seas associated
with a fresh pulse of NW swell are peaking near 15 ft in the 
area of strong trades W of 135W as depicted by a recent altimeter
pass. Seas will slowly subside as the swell propagates southeast
the next few days. A cold front will move into the far northern 
waters Saturday. This will usher in another set of northerly 
swell into the area. 

$$
AL