341 
AXPZ20 KNHC 310938
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
938 UTC Tue Jul 31 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 0600 UTC surface analysis and satellite imagery through
0900 UTC. 

...SPECIAL FEATURES...

Clusters of thunderstorms continue to pulse within 240 nm northwest
of a broad 1009 mb low pressure centered near 12N114W along the 
monsoon trough, around 270 nm W-NW of Clipperton Island. Various
recent microwave passes continue to show low level organization
is poor. While the latest satellite images show tops warming 
slightly indicating weakening convection, thunderstorms have been
persistent near the low pressure for a couple of days, and E-SE 
shear acting on the system yesterday is slightly weaker today. As
environmental conditions gradually become more conducive for 
development, a tropical depression could form during the next few
days while the disturbance moves generally westward at 10 kt. 
The latest Tropical Weather Outlook gives this system a medium 
change of tropical cyclone formation through 48 hours.

...TROPICAL WAVES...

A tropical wave is along 95W N of 03N. Scattered moderate to
strong convection is observed along the coast of Guatemala east
of the tropical wave, probably mostly due to local drainage
convergence along the coast.

Another tropical wave is along 135W from 09N to 23N. Scattered 
moderate convection is observed near where the wave interacts 
with the intertropical convergence zone from 07N to 10N between 
129W and 132W.

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

The monsoon trough axis extends 09N78W to 13N105W to low 
pressure located near 12N113W to 10N125W to 12N135W. The
intertropical convergence zone continues from 10N125W to beyond
09N140W. Outside of the convection associated with the tropical 
waves and low pressure, scattered moderate convection is noted 
from 07N to 10N between 130W and 135W. 
  
...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Gulf of Tehuantepec: Mainly gentle to moderate winds will prevail 
across the Gulf of Tehuantepec. Wind are forecast to increase 
across the Tehuantepec area late this week as a low pressure area
develops to the south.

Elsewhere, a weak ridge will dominate the offshore forecast
waters W of the Baja California Peninsula, maintaining a weak 
pressure gradient, with light to gentle NW winds across the 
region and 3 to 5 ft seas. Then, seas are expected to build to 
5 to 7 ft in long period swell late this week, but mainly N of 
Punta Eugenia.

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

Gulf of Papagayo: Moderate easterly flow is expected through the
week, occasionally pulsing to fresh.
  
Gentle to occasionally moderate E winds are forecast elsewhere N 
of the monsoon trough which is meandering between 08N and 10N. 
Moderate to locally fresh southerly winds are forecast S of the 
monsoon trough through the week accompanied by 5 to 7 ft seas.
  
REMAINDER OF THE AREA...   

Elsewhere, a ridge will persist north of 20N west of 120W 
through the week, supporting moderate N to NE winds and 4 to 6 
ft seas. Moderate to locally fresh southerly winds are forecast 
elsewhere S of the monsoon trough or roughly S of 15N for the 
next several days. 

An area of low pressure is expected to form several hundred miles
south of the Gulf of Tehuantepec late this week. Gradual development
of this system is possible thereafter as it moves west-
northwestward off the coast of Mexico. This low pressure area is 
forecast to bring an increase in winds and seas across the 
Tehuantepec area Fri night through Sat night.
  
$$
Christensen