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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 200905
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
711 UTC Fri Oct 20 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.

...TROPICAL WAVES...

The axis of a tropical wave is near 91W north of 04N, moving W 
around 5 kt. Scattered moderate and isolated strong convection is
noted from 06N to 08N between 91W and 93W. 

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

The monsoon trough extends from 10N85W to 08N107W to 09N122W. 
The ITCZ continues from 09N122W to beyond 11N140W. Scattered 
moderate isolated strong convection is noted within 60 nm of the
monsoon trough between 93W and 100W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

High pressure over the Gulf of Mexico has weakened over the past
24 hours. This has loosened the pressure gradient over the Gulf 
of Tehuantepec and brought an end to the latest gale force gap
wind event. Winds are currently near gale force. The pressure
gradient will weaken further this weekend with winds diminishing
to 20 kt or less Saturday. Another cold front will enter the 
Gulf of Mexico on Sunday. This front will help produce another 
gale force gap wind event over the Gulf of Tehuantepec early 
next week. 

The pressure gradient between building high pressure west of the
Baja California Peninsula and a surface trough over the Gulf of
California will strengthen winds west of Baja California Norte
early this weekend before diminishing to 20 kt or less by Sunday.
Long period NW swell will propagate into the waters off Baja 
California Norte today. Seas will peak near 15 ft off the coast 
of Baja California Norte Saturday before starting to subside. The
swell will propagate southward, with seas 8 ft or greater 
spreading down the entire offshore forecast zones off the coast 
of Baja California through the weekend before starting to subside
below 8 ft early next week. 

High pressure building over the Great Basin region will help
strengthen NW winds over the Gulf of California from Sunday 
through Tuesday. 

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

Gentle to moderate winds will prevail over the forecast area the
next several days. Seas of 8 to 9 ft prevailing across the 
southernmost zones will subside by early Saturday.

REMAINDER OF THE AREA...

A weakening cold front over the far northwest waters has helped
usher in a fresh set of NW swells to the area. Seas near 15 ft 
will spread west to east over the waters north of 28N today. The
swell will push southeastward across most of the region, while 
gradually subsiding, the next few days. Peaks seas will drop 
below 12 ft Sunday afternoon and seas associated to this swell 
are expected to subside below 8 ft by Wednesday.

$$
AL