000
AXPZ20 KNHC 050915
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
813 UTC Fri Jan 5 2018

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: The pressure gradient between
high pressure along eastern Mexico and a surface trough over the
eastern north Pacific is supporting gale force winds over the 
Gulf of Tehuantepec. The gale force winds are expected to 
continue into the first half of the weekend, before diminishing 
below gale force Sunday. Swell generated from the persistent gale
force winds will propagate downstream of the Gulf of 
Tehuantepec, with seas 8 ft or greater reaching as far S as 05N 
and west to 110W by tonight. Please refer to the latest high seas
forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more 
details.

A low pressure system will develop along a trough over the 
northwestern waters today. The trough currently extends from
26N131W to 17N133W. Overnight ASCAT pass depicts strong to near 
gale force winds within 60 nm west of the trough, and fresh to 
strong winds within 90 nm east of the trough. The pressure 
gradient between the deepening low pressure area and high 
pressure to the west of the forecast waters will support gale 
force winds west of the low pressure center. Gale force winds are
expected to develop by tonight, and last into the first half of 
the weekend. The low will lift north of the area Monday. Seas are
forecast to build to 12-15 ft within the area of gale force 
winds. Please refer to the latest high seas forecast issued under
AWIPS/WMO headers HSFEP2/FZPN03 for more details.

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

A surface trough extends from 08N82W to 05N93W. The ITCZ extends
from 05N93W to 09N132W to beyond 08N140W. Scattered moderate 
convection is noted within 60 nm N of the ITCZ between 124W and 
128W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see Special Features section above for more details about
the ongoing gale force wind event in the Gulf of Tehuantepec.
Looking ahead another gale force gap wind event is possible early
next week as high pressure builds behind the next cold front
forecast to move into the Gulf of Mexico. 

NW swell will propagate into the offshore waters off Baja
California Norte Tuesday, with seas building to near 14 ft by Tue
night. Elsewhere, relatively tranquil marine conditions are 
expected during the period. 

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

Winds will pulse to near gale force over the Gulf of Papagayo 
tonight and Sat night before diminishing Sun. Light to gentle 
NE-E winds will prevail elsewhere to the N of 09N, with gentle to
moderate S to SW winds expected S of 09N.

REMAINDER OF THE AREA...

Please see Special Features section above for details about the 
forecast gale center over the NW waters. 

Overnight altimeter pass depicts seas of 8 ft or greater west of
a line from 30N125W to 16N128W. The swell will continue to
subside over the next couple of days. A cold front is expected 
to move into into the northern waters next Monday, followed by 
increasing winds and a fresh set of NW swell.

$$
AL