000
AXPZ20 KNHC 130935
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Wed Dec 13 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: High pressure over eastern
Mexico is helping produce a tight pressure gradient across the 
Isthmus of Tehuantepec in southern Mexico. The gradient supports 
minimal gale force winds over the Gulf of Tehuantepec, as shown 
in an ASCAT pass at 0320 UTC. High pressure will shift eastward 
and weaken through tonight, and winds will diminish winds below 
gale force later today. Winds will continue to decrease on Thu. 
Another brief gale force gap wind event is possible Fri night. 

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

The monsoon trough extends from 09N79W to 09N86W to 05N94W. The 
ITCZ continues from 05N94W to 09N118W to 09N140W. Scattered 
moderate isolated strong convection is noted from 08N to 13N 
between 111W and 138W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gulf of Tehuantepec: Please see Special Features section above 
for details on the ongoing gale wind event. 

Fresh to strong NW winds across the N Gulf of California will 
diminish  later today, then strengthen again Thu night through 
Sat. Gentle to moderate winds will prevail elsewhere over the 
offshore Pacific waters, with seas in the 4-6 ft range.

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

Strong winds will prevail across the Gulf of Papagayo through 
early Fri, then strengthen once again Sat night. Moderate to 
fresh N winds will funnel through the Gulf of Panama Thu and Fri.

REMAINDER OF THE AREA...

The pressure gradient between high pressure centered north of 
the area and lower pressure in the vicinity of the ITCZ is 
maintaining an area of fresh winds from 15N to 19N between 120W 
and 127W. The area of high pressure will weaken over the next 24 
hours, and winds will diminish to 15-20 kt by tonight. An ASCAT 
pass at 0650 UTC revealed strong southerly winds in the NW part 
of the area, with gale force winds just west of 140W between 35N 
and 38N associated with a cold front west of the area. NW swell 
and wind waves from this area will spread into NW waters, but 
not push far past 130W as the front weakens and shifts away from 
the area. Associated seas will peak near 13 ft tonight and Thu 
morning before starting to subside. 

$$
Mundell