000
AXPZ20 KNHC 182205
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Thu Oct 18 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 1800 UTC surface analysis and satellite imagery through 
2115 UTC.

...SPECIAL FEATURE...

An extensive area of disorganized showers and thunderstorms 
extends from Central America westward to the south of the coast 
of Mexico for about 300 nm. A broad area of low pressure is 
embedded within this region of disturbed weather near the Gulf 
of Tehuantepec. Moreover, satellite images indicate that the 
system has lost organization compared to the past couple of 
days. However, environmental conditions still appear conducive 
for development, and a tropical depression or tropical storm is 
likely to form over the weekend or early next week while the 
system moves generally west-northwestward near or just offshore 
the coast of southern Mexico. Currently, winds and seas 
associated with the gap wind event in Tehuantepec merged with 
the low pressure located near 13N95W. Fresh to strong winds are 
within 210 nm north semicircle of the low with seas to 10 ft. 
Even though that the system has slightly weakened and high 
pressure north of the area is forecast to decrease, there is 
still a window for gale-force winds to develop late Friday 
morning into the afternoon hours. See the East Pacific Tropical 
Weather Outlook under AWIPS/WMO header MIATWOEP/ABPZ20 KNHC for 
further details.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough extends from 13N90W to a low near 13N95W to 
12N116W to 08N123W to 12N134W to 10N140W. Scattered moderate 
convection is from 10N to 14N between 115W and 118W, and from 
07N to 15N W of 127W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO... 

The pressure gradient between a trough along western Mexico and 
surface ridging west of the Revillagigedo Islands will maintain 
gentle to moderate NW winds W of Baja California through Tue. 
Seas over this region will be 4-6 ft during that period. 
Afterwars, seas are forecast to increase in the offshores of 
Baja California Sur as a low pressure/possible tropical cyclone 
approaches from the SE.

High pressure N of the Gulf of California is supporting fresh to 
strong winds N of 29N as indicated by latest scatterometer data. 
Seas in this area are to 5 ft. This center of high pressure is 
forecast to move east by Friday evening, and winds will decrease 
to moderate. Otherwise, gentle to moderate winds will dominate 
across the remainder gulf through Sun. Light to gentle winds are 
expected afterwards through Tue.

The gap wind event in the Gulf of Tehuantepec has merged with 
the area of low pressure mentioned in the Special Features 
section. See section above.

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

Gentle to moderate SW monsoonal flow will dominate the offshore 
waters through early Sun when fresh SW winds are expected to 
enter the offshore waters of Ecuador Colombia and Panama. Seas 
of 8 ft in SW swell are expected in these zones continuing 
through Monday.

Widespread showers and thunderstorms associated with the broad 
area of low pressure mentioned in the Special Features will 
continue to affect portions of Central America and adjacent 
Pacific coastal waters.
  
REMAINDER OF THE AREA...

A surface trough extending from 30N138W to 25N140W will 
dissipate tonight. Long period NW swell associated with the 
trough will cause seas to build to between 8 and 10 ft N of 12N 
W of 131W.

$$
NR