000
AXPZ20 KNHC 220956
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
713 UTC Sun Jan 22 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 FEATURE...

A vigorous cold front will head southeastward across the Gulf of
Mexico today and tonight. High pressure building in behind the 
front over the southwestern Gulf of Mexico Monday will bring 
gale force winds to the Gulf of Tehuantepec beginning around 
0900 UTC Monday morning. The high will slide quickly eastward, 
which will permit winds to remain above gale force for only about
12 hours. Please see the latest East Pacific high seas forecast 
under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for further details. 

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

The ITCZ extends from 06N99W to 07N109W to 05N124W to 07N134W to
07N140W. No significant convection.

...DISCUSSION...   

...A series of strong cold fronts and a prolonged period of 
unusually large swell will continue to affect most of the 
forecast area through mid week...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Strong northwest winds and seas of 12-26 ft are affecting the 
waters north of 23N. Very large northwest swell will continue to
propagate southeastward, continuing into the deep tropics during
the next several days. Seas as high as 26 ft have been observed
in satellite-derived wind data off Baja California Norte near
29N118W at 0510 UTC. The leading edge of high seas will reach 
the Revillagigedo Islands around noon today. Ridging behind the 
front will allow fresh to locally strong north winds to spread 
into the southern Gulf of California to near Cabo Corrientes late
Sunday. Another cold front will produce a reinforcing round of 
large long period NW swell, which will maintain seas in the 12 to
20 foot range through Tuesday. Strong winds sustaining the swell
event will diminish by Tuesday as the high weakens, with seas 
decreasing below 12 ft in the offshore Mexico waters Wednesday 
night. However, seas of 8 to 10 ft will persist west of 100W 
through the end of the week. High pressure building in behind a 
strong cold front in the Gulf of Mexico will increase the 
pressure gradient across the Isthmus of Tehuantepec and cause gap
winds to increase to gale force over the Gulf of Tehuantepec on
Monday morning. Please see the special features section for more
details. 
  
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...

Light to gentle southeast to east winds will prevail across most 
of the region through Tuesday. Seas will generally range between
3 and 5 ft until Tuesday, then build about a foot in response to
building NW swell. Fresh to strong gap winds will pulse in the 
Gulfs of Papagayo and Panama Tuesday night and Wednesday night as
high pressure passes north of the Caribbean basin.

REMAINDER OF THE AREA...

The pressure gradient between a cold front crossing the forecast
area from 30N129W to 26N134W to 23N140W and 1021 mb high 
pressure centered near 26N121W is supporting strong southwesterly
winds ahead of the front N of 27N and W of 122W. Strong NW winds
are occurring over all the forecast waters west of the front. A 
large NW swell event continues spreading across the waters with 
12 ft seas dominating north of 21N and reaching as high as 26 ft 
along 29N. Seas of 8 ft or greater encompass the waters NW of a 
line from 19N107W to 14N110W to 04N129W to 04N140W. Large long 
period swell will continue to sweep southeastward with 8 ft seas 
nearing the equator early Monday. Global models continue to show 
gale force winds associated with the cold front currently 
crossing the northern waters will remain just north of 30N 
through tonight. These winds will continue to generate NW swell. 
Seas of 18 to 24 ft can be expected west of the front where the 
near gale winds are occurring. Forecast models are in general 
agreement in developing low pressure over the western waters near
12N134W on Thursday and Thursday night. A large area of fresh to
strong winds will be possible in the vicinity of the low from 
12N to 26N W of 120W by Friday morning.

Otherwise, gentle to moderate winds will prevail elsewhere, with
4-7 ft seas expected through Monday. NE swell from the 
Tehuantepec high wind event will increase seas in the Gulf of
Tehuantepec to 8-13 ft on Monday. 

$$
cam