000
AXPZ20 KNHC 271532
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1500 UTC Wed Dec 27 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
1500 UTC.

..SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: Building high pressure over 
the western Gulf of Mexico and eastern Mexico will induce gale 
force northerly winds through the Chivela Pass into the Gulf of 
Tehuantepec tonight, and continue through Fri morning. Peak seas 
should reach about 13-14 ft early Friday. 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 axis extends from 1009 mb low pressure near
05N71W to 07N110W. The trough then transitions to the 
intertropical convergence zone and continues west to 
10N118W and beyond 08N140W. Scattered moderate convection is
noted from 07N to 13N between 105W and 115W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please refer to the special features section above for details 
of a Gulf of Tehuantepec Gale event. A fairly static synoptic 
pattern associated with a nearly stationary subtropical high 
west of California and a surface ridge extending SE from the 
high will persist for several days. This will maintain gentle to
moderate NW to N winds off Mexico through the weekend. Seas will
be generally 4-6 ft in offshore waters and 2-4 ft in the Gulf of
California.

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

Moderate high pressure gradient in the western Caribbean will 
continue to support fresh to strong NE winds from 09N to 11N 
east of 90W, including the Gulf of Papagayo, through Sun night 
with seas to 7-9 ft primarily from NE wind waves. Mainly gentle 
winds are expected elsewhere through the end of the week, with 
offshore seas generally 4-5 ft.

REMAINDER OF THE AREA...

Long-period NW swell is producing 8-10 ft seas north of 15N and 
west of 125W. Seas will continue to gradually diminish today as 
the peak swell continues moving SE. Divergence aloft on the
southeast side of an upper trough along 120W is support the scattered
convection from 07N to 13N between 105W and 115W. A surface
trough and weak low pressure area is expected to form along the
intertropical convergence zone Thu related to this upper trough,
and will drift westward over the next 48 hours before the surface
trough dissipates. This will enhance trade wind flow slightly 
from 15N and 20N between 120W and 130W through Fri, with seas 
building to 8 ft due to a mix of NE wind waves and longer period 
NW swell. 

$$
Christensen