000
AXPZ20 KNHC 210145
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0145 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 0000 UTC surface analysis and satellite imagery through
0145 UTC.

...TROPICAL WAVES...

The axis of a tropical wave is N of 07N along 95W moving W at 10
to 15 kt. Scattered moderate and isolated strong convection is
from 07N to 11N between 93W and 99W.

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

The monsoon trough axis extends from 09N75W to 11N87W to 08N98W 
to 08N110W to 09N119W. The intertropical convergence zone axis
extends from 09N119W to 09N130W to 09N140W. Scattered moderate
and isolated strong convection is from 07N to 10N between 88W and
92W, from 05N to 07N between 113W and 117W, and also from 09N to
11N between 131W and 135W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

High pressure over the western Gulf of Mexico and eastern slopes
of the Sierra Madre Oriental has weakened during the past 24 
hours. This has loosened the pressure gradient over the Gulf of 
Tehuantepec and allowed for a decrease in northerly flow to fresh
to strong. 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 evening. This
front will bring strong to near gale force winds to the Gulf of 
Tehuantepec Sun night, and gale force to even strong gale force 
winds to the Gulf of Tehuantepec Mon night through Wed night.

The pressure gradient between building high pressure northwest 
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. Strong NW winds will extends down the 
peninsula as far S as 24N this weekend. Winds are expected to 
diminish to 20 kt or less by Saturday afternoon. Long period NW 
swell generated to the NW of a dissipated cold front which was 
over the N central waters will invade the waters off Baja 
California Norte this evening. Seas will peak near 15 ft off the 
northernmost coast of Baja California Norte Saturday before 
starting to subside. The swell will propagate SE, with seas 8 ft 
or greater enveloping all of the offshore forecast zones W of 
Baja California through the weekend before subsiding below 8 ft N
of 26N by Tuesday afternoon through the middle of next week.

High pressure building over the Great Basin region of the 
western United States will cause NW winds to strengthen over the 
Gulf of California through Tuesday, diminishing thereafter as 
the gradient weakens. Winds will be strongest on Sunday night
through Monday when seas peak around 8 ft.

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 N of
the monsoon trough during the next several days. Seas of 7 to 9 
ft maintained by decaying SE and S swell across the southernmost 
zones W of Ecuador will subside by early Saturday. Moderate to 
fresh SW winds will cause seas to build to around 8 ft W of 
Colombia and S of Panama between 03N and 06N between 80W and 84W 
on Saturday.

REMAINDER OF THE AREA...

A set of large NW swell with seas near 15 ft will continue to
propagate SE while gradually subsiding late in the weekend into
early next week. The highest seas will subside to less than 12 
ft Sunday afternoon and seas associated to this swell are 
expected to subside to less than 8 ft by Wednesday.

$$
Lewitsky