000
AXPZ20 KNHC 131554
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Tue Jul 13 2021

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

A broad area of low pressure located near 12N108W or 800 miles 
south-southeast of the southern tip of the Baja California 
peninsula, is producing a small but concentrated area of showers
and thunderstorms from 12N to 17N between 104W and 111W. 
Environmental conditions are forecast to be favorable for 
development, and a tropical depression is likely to form in a 
couple of days while the low moves westward at 10 to 15 kt. The 
latest Tropical Weather Outlook gives this system a medium chance
of tropical cyclone formation within the next 48 hours.

...TROPICAL WAVES...

A tropical wave extends along 96W from 02N northward into the 
Gulf of Tehuantepec. The wave is moving W at around 10 to 15 kt.
Scattered moderate convection is noted W of the wave axis from 
09N-16N between 95W-99W.

Another tropical wave is along 108W from 01N to 15N. The low 
pressure mentioned in the Special Features section above is 
along the wave axis.

The axis of a third tropical wave extends along 135W from 05N to
18N, moving W at around 10 to 15 kt. Scattered showers are noted  
where the wave meets the monsoon trough from 09N to 12N between 
132W and 134W.

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

The monsoon trough extends from 10N86W to 14N117W to 11N133W. The
ITCZ extends from 11N136W to beyond 10N140W. Aside from the convection 
related to the tropical waves and special feature low described 
above, scattered moderate convection is noted from 04N to 08N and
E of 92W, from 06N to 15N between 115W and 129W, and along the
boundaries and W of 130W. 

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A weak ridge dominates the offshore forecast waters of Baja 
California producing gentle to moderate NW-N winds and seas of 
4-6 ft. Light to gentle winds are noted elsewhere across the 
offshore waters of Mexico, except in the Tehuantepec region where
fresh to locally strong N-NE winds are noted per scatterometer
data, with seas to 8 ft.

For the forecast, a surface ridge will continue to extend over 
the waters W of Baja California peninsula over the next several 
days. Gentle to moderate NW-N winds will prevail the remainder of
the week. Light to gentle breezes will persist off southern 
Mexico through Fri. In the Gulf of California, mainly gentle to 
moderate southerly winds are expected over the next several days,
with the exception of moderate to locally fresh SE-S winds, with
seas of 3-5 ft in the northern part of the Gulf. Fresh to strong
northerly winds are forecast in the Tehuantepec region through 
Thu, with seas building up to 9 or 10 ft.

An area of low pressure is forecast to develop south of the Gulf of 
Tehuantepec late this week and move westward at 10 to 15 kt, 
well offshore of the southern coast of Mexico. Environmental 
conditions are expected to be favorable for gradual development, 
and a tropical depression is likely to form this weekend. Based 
on latest Tropical Weather Outlook, this system has a high chance
of tropical cyclone formation through 5 days.

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

Fresh to locally strong NE-E winds and seas to 8 ft are noted in
the Papagayo region. Light winds are north of the monsoon trough
with gentle to moderate winds south of the monsoon trough. Seas 
mostly range 5 to 8 ft, with 8 to 9 ft seas between Ecuador and 
the Galapagos Islands.

For the forecast, fresh to locally strong NE-E winds will continue
to pulse across the Papagayo region through today, and then again
Wed through Thu. Elsewhere, gentle to moderate southerly flow 
will prevail south of 10N through the week, with light to gentle 
breezes north of 10N. Large swell from the Southern Hemisphere 
will continue to propagate across the waters between Ecuador and 
the Galapagos Islands through at least Wed. Seas will continue to
be 8 to 9 ft in this area, reaching as far north as the offshore
waters of western Panama. 

REMAINDER OF THE AREA...

A surface ridge dominates the northern forecast waters and extends
from a 1030 mb high pressure located near 39N146W. Recent 
satellite derived wind data show moderate to locally fresh NE-E 
winds N of the monsoon trough to about 20N between 118W-134W. The
pressure gradient between the ridge and a low pressure along the
monsoon trough near 13N124W supports these winds. Fresh NE and 
seas to 8 ft are observed over the far NW corner of the forecast 
area. 

Two tropical cyclones are forecast to develop across the forecast
region, one later this week and the second one during the upcoming
weekend. 

$$
ERA