000
AXPZ20 KNHC 080321
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Thu Dec 8 2016

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 0000 UTC surface analysis and satellite imagery through
0300 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: Light winds during the day
will prevail through Thursday afternoon, with northerly winds at
night in nocturnal drainage flow. Strong high pressure building
over southern Mexico Thursday night behind a cold front in the
Gulf of Mexico will induce northerly winds in Tehuantepec waters
to rapidly increase to gale force early Friday, then continue
through Saturday night. Highest winds are expected to be 45 kt
Friday night. Max seas will build to 16-18 ft downstream from
the Tehuantepec coast. Gale force winds will diminish to 15-20
kt by early Sunday.

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

The monsoon trough axis extends from 10N85W to 10N107W to
09N115W. The ITCZ axis continues from 09N115W to 08N140W.
Scattered moderate convection is within 60 nm either side of
the axis between 101W and 128W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gulf of California: Scatterometer data shows a surface low in
northern waters centered near 30.6N 113.7W. A surface trough
extends over north-central waters from the low to 26N111W. A
weak cold front will slide southward across the area overnight,
with winds shifting to N-NW behind the front. A tighter pressure
gradient will allow winds to become fresh to strong in the
central Gulf of California from 24N to 28N Thursday afternoon
through Friday morning, with seas building to 5-7 ft.
 
High pressure is centered near 29N125W. Gentle to moderate
anticyclonic flow is expected west of Baja California through
Friday. Combined seas in northwest swell of 4-7 ft will subside
from northwest to southeast overnight. Offshore winds north of
28N will become fresh to strong this weekend as the gradient
tightens, with seas building to 7-9 ft.
    
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...

Gulf of Papagayo: Moderate to fresh nocturnal east-northeast
winds are expected the next couple of nights, becoming fresh to
strong Friday night and Saturday night as the gradient across
the region tightens. Max seas will build to 7-8 ft downwind of
the Papagayo region.

Light to gentle northerly winds and combined seas of 2-4 ft are
occurring elsewhere north of the monsoon trough near 10N. Light
to moderate southwest flow is observed south of 10N, with
combined seas of 3-5 ft in long period southwest swell.

REMAINDER OF THE AREA... 

High pressure centered near 29N125W anchors a ridge mainly along
28N west of 115W. The high will drift eastward through Friday. A
cold front is expected to stall over the far northwest waters
Thursday, then weaken and drift westward Thursday night.

Gentle to moderate northwest to north flow is expected northeast
of the ridge the next 24 hours. Moderate to fresh east-northeast
trades will prevail south of the ridge, with highest winds just
north of the ITCZ. 5-7 ft seas in the deep tropics will build to
7-9 ft this weekend north of the convergence zone west of 125W.
  
$$
Mundell