000
AXPZ20 KNHC 150248
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
248 UTC Wed Nov 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 0000 UTC surface analysis and satellite imagery through
0230 UTC.

...SPECIAL FEATURES...

A gale warning remains in effect for the Gulf of Tehuantepec. An
earlier scatterometer pass showed 35-40 kt winds within about 60
nm of the coast in the Gulf of Tehuantepec. High pressure north
of the area along with lower pressure reaching from the southwest
Caribbean to the south of Tehuantepec will continue to support
the strong to gale force gap winds through tonight into early
Wednesday morning. The ridge will weaken slightly, allowing winds
to diminish below gale force, but strong gap winds will persist 
into Sat. Winds are forecast to increase again to gale force by 
Sat night as a strong cold front moves into the western Gulf of 
Mexico. Marine guidance suggests winds of 30-40 kt and building 
seas of 14-15 ft by early Sun morning. 

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

The monsoon trough extends from 09N84W to 07N125W then will
transition to the intertropical convergence zone and extend to
11N140W. Scattered moderate convection is noted within 60 nm of
the monsoon trough axis east of 110W and between 115W and 120W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please refer to the Special Features section for information 
regarding the ongoing Gulf of Tehuantepec gale warning.

Weak ridging west of the area is supporting moderate to fresh 
winds and 5 to 7 ft seas off Baja California, with the help of
residual northwesterly swell. The ridge will weaken and shift
closer to the coastline through Wed, allowing winds to diminish
through mid week through Fri. The winds increase again to 15 to
20 kt off Baja California Norte by late Fri as stronger ridging
builds north of the area, then shifts eastward through Sun
allowing the winds to diminish again.

Weak northwest winds will persist across the Gulf of California
through Fri under the weak pressure pattern. A cold front will
move across Baja California Norte and the northern Gulf of
California late Fri and Sat. Strong high pressure building behind
the front north of the area over the Great Basin will allow
strong winds over the northern Gulf Sat, reaching into the
central Gulf of California Sun. These winds will diminish
starting late Sun as the front dissipates and the high pressure
north of the area shifts east.

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

Earlier ship observations show fresh to strong southwest to west winds
to the south of western Panama. These winds are expected to 
persist with seas building to 9 ft mainly off the Azuero 
peninsula through late Thu. The winds and seas are the result of 
a tight pressure gradient related to 1007 mb low pressure 
centered over the southwest Caribbean. The fresh to strong winds 
and seas to 9 ft will persist off western Panama through Thu, 
when the low pressure weakens and starts drifting farther north. 
Elsewhere, gentle to moderate winds and seas of 4 to 6 ft are 
expected N of the monsoon trough, which will fluctuate between 
08N and 10N, with moderate to locally fresh S to SW winds and 
seas of 5 to 7 ft S of the monsoon trough through Thu. 

REMAINDER OF THE AREA...

A 1011 mb low pressure area is centered near 20N132W moving NW 
at 10 kt. An area of fresh to strong winds and seas to 10 ft is 
noted within about 150 nm N semicircle of low center. A swirl of
low clouds is associated with this low. A passing short wave 
trough and dry air aloft will cause the low to weaken into a 
trough during the next 24 hours. Winds and seas north of low 
will continue to diminish today, and early on Wed winds will be 
less than 20 kt with seas less than 8 ft. 

A cold front is entering the discussion area, passing to the
southeast of 30N140W, ahead of a 1011 mb low pressure area.
Earlier scatterometer and ship observations indicated fresh to
strong southwest winds ahead of the front. Long period swell is
also propagating into the region, allowing combined seas to 10 ft
over the region north of 26N and west of 135W. The front will 
stall and start to dissipate from southern California to 25N140W 
by late Wed. Residual northerly swell to 8 ft will persist north 
of 26N and west of 135W through late Fri.

$$
Christensen