000
AXPZ20 KNHC 281533
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1300 UTC Tue Nov 28 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 1200 UTC surface analysis and satellite imagery through
1515 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: A tight pressure gradient is
across southern Mexico between high pressure over central Mexico 
and the western Gulf of Mexico and lower pressures in the deep 
tropics. The combination of this gradient and nocturnal
drainage flow are resulting in gale force gap winds through the 
Gulf of Tehuantepec this morning. Seas are 10-13 ft. The winds 
should subside below gale force around 1500 UTC today. Lingering
NE swell from the gap wind event with 8 ft or greater seas will 
reach more than 500 nm offshore of the Gulf of Tehuantepec. 
Another round of gale force winds are expected Wed evening 
through Friday night.

INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough axis extends from 09N84W to 06N100W to 1010 mb
low at 07N106W to 06N113W, where it transitions to the 
intertropical convergence zone and continues to 09N130W to 
beyond 10N140W. Scattered moderate convection is from 05N to 09N
between 90W and 99W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

See Special Features paragraph above for information on the 
Gulf of Tehuantepec Gale Warning. 

The tail end of a cold front extends from NW Mexico near 31N110W
across the N Baja California to 29N115W. Gulf of California N of
30N NW has winds 20 to 25 kt. Seas less than 8 ft. The front will
dissipate later today. Fresh to locally strong NW winds are 
occurring off the Pacific coast of Baja California. NW swell of 
8 to 12 ft will follow the front, with the leading edge of 8 ft 
seas reaching the Revillagigedo Islands by late Wed or early Thu.
Seas W of Baja California and Revillagigedo Islands will remain 
above 8 ft through late week, as another reinforcing group of NW 
swell in excess of 8 ft propagates into the waters.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR...
  
Gulf of Papagayo: A tight pressure gradient between high pressure
over northern Central America and lower pressure across the
southwest Caribbean will enhance overnight drainage effects and
result in pulses of fresh to strong gap winds through the Gulf of
Papagayo through this evening, and to a lesser extent Wed into 
Wed evening. Seas are to 8 ft presently until this evening.  
Stronger pulses are likely later in the week.

Light to gentle N to NE winds, and 3 to 5 ft seas are expected 
elsewhere through Sat north of the monsoon trough. Moderate 
southerly winds, and 4 to 6 ft seas, are forecast south of the 
monsoon trough. Northerly swell generated in the Gulf of 
Tehuantepec has reached the western part of forecast zone PMZ111 
(offshore waters of Guatemala and El Salvador) with seas to 9 ft,
diminishing today. Additional large swell will reach the western
portion of zone by Thu through the end of the week.

REMAINDER OF THE AREA... 

An active upper level jetstream is supporting clusters of moderate
convection from 21N to 28N between 125W and 140W. A large area 
of NW swell of 8 to 15 ft will continue to propagate across the 
region with the leading edge of 8 ft seas reaching from the 
central Baja California peninsula to 05N140W by this evening;  
then from 28N115W to 20N120W to 05N140W Wed; and from 28N115W
to 16N110W to 00N140W Thu. A re- enforcing batch of NW swell 
will reach the waters late this week, as seas of 8 to 12 ft cover
nearly the entire forecast waters S of 30N W of 110W Fri through
the upcoming weekend. 

$$
Formosa