000
AXPZ20 KNHC 232123
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1927 UTC Fri Jun 23 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 1800 UTC surface analysis and satellite imagery through
2100 UTC.

...SPECIAL FEATURES...

Shower and thunderstorm activity has begun to show signs of 
organization in association with a broad area of low pressure
located a couple hundred miles south-southwest of the Gulf of 
Tehuantepec near 13N96W. Environmental conditions appear conducive
for development, and this system is likely to become a tropical 
depression by late this weekend or early next week while it moves
slowly west-northwestward parallel to the coast of Mexico. 
Interests along the southwestern coast of Mexico should monitor 
the progress of this system. Winds and seas are forecast to 
gradually increase across the offshore forecast waters as this 
system continues to move parallel to the coast of Mexico.
Currently, the forecast shows winds of 20-30 kt and seas of 8-12
ft in association with this system by Sunday afternoon. The
latest Tropical Weather Outlook gives this low a high chance of
formation through 48 hours.

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

The monsoon trough extends from 09N84W to the developing low 
pressure near 13N96W to 10N112W to 09N125W. The ITCZ axis
continues from 09N125W to beyond 06N140W. Scattered moderate
isolated strong convection is from 09N to 12N between 92W and 
100W, and from 07N to 09N between 97W and 103W.

...DISCUSSION...   

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A weak 1015 mb high pressure is centered near 27N120W. A trough 
extends from a low pres located north of area across the NW
waters. In association with this weather pattern, the most 
recent scatterometer data indicate mainly light and variable 
winds across most of the forecast waters N of 20N W of 120W. 
Moderate to locally fresh NW winds are expected off the Baja 
California Peninsula tonight into Saturday as the high pressure 
moves toward the SW and slightly strengthens. Moderate to fresh 
NW winds are noted near Cabo Corrientes, likely due to the 
pressure gradient between a ridge to the west and low pressures 
across inland Mexico.

Mainly light to gentle breezes are expected across the Gulf of
California tonight into Saturday, with the exception of gentle 
to moderate winds around the Sonora low located over the northern
waters, with seas of 2-4 ft. Gentle to moderate southerly winds 
are expected on Sunday, with seas of 4-5 ft across the southern 
portion of the Gulf. 

See Special Features for more information on a developing low
pressure located southwest of the Gulf of Tehuantepec. 

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

Gentle to moderate southwest to west winds are expected across 
most of the region during the forecast period, with the exception
of mainly S winds between Ecuador and the Galapagos Islands. 
Seas will subside to 4-5 ft during into early next week. 

REMAINDER OF THE AREA...

A surface trough extends from a 1010 mb low pres located north of
area near 33N129W to 28N136W. Moderate to fresh northwest winds 
were noted per scatterometer data between the trough and high 
pressure farther west. Otherwise, weak high pressure dominates 
the remainder of the area north of the convergence zone, 
producing mainly light and variable winds. An altimeter pass 
shows seas of 8 to 12 ft, in northerly swell, affecting the 
waters N of 21N W of 120W. Seas will gradually subside through 
the upcoming weekend.

$$
GR