Eastern Pacific Tropical Weather Discussion

180
AXPZ20 KNHC 201614
TWDEP 
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Thu Aug 20 2026
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.
...TROPICAL WAVES...
The axis of a tropical wave is entering eastern portions of the
Tropical Pacific basin along 80W, north of 04N, moving westward 
at 15 to 20 kt. Scattered to numerous moderate to strong 
convection is noted from 04.5N to 11N between 77W and 86W.
The axis of a tropical wave is near 98W from 05N to 18N, moving 
westward at 15 to 20 kt. Scattered to locally numerous moderate 
to strong convection stretches from 06N to 14.5N between 90W and
105W. Environmental conditions appear favorable for gradual development, 
and a tropical depression is likely to form this weekend while the 
system moves generally west-northwestward, remaining well offshore 
of Mexico. This system has a low chance of tropical cyclone 
formation in the next 48 hours, and a high chance in the next 7 
days. Regardless of development, expect increasing winds and seas
will impact the outer offshore waters of southwestern Mexico. 
The axis of a tropical wave is near 112W from 05N to 16N, moving
westward at around 15 to 20 kt. A broad area of low pressure 
associated with this tropical wave near 09.5N111.5W is producing
scattered to numerous moderate to strong convection from 04N to 
12N between 107W and 117W. Fresh to locally strong winds are
found within 120 nm of the N semicircle to the low, with locally
rough seas there. Environmental conditions are forecast to be 
marginally favorable for gradual development of this system over
the weekend as it moves westward or west-northwestward at 10 to
15 kt.
Please refer to the latest NHC Tropical Weather Outlook at 
website: https://www.nhc.noaa.gov/text/MIATWOEP.shtml for more 
details on these systems.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 10.5N75W to 07N81W to 1007 mb 
low pressure near 09.5N111.5W to 06N130W to beyond 10N140W. 
Other than the convection described above with three tropical 
waves, scattered moderate isolated strong convection is noted 
from 05N to 14.5N between 87W and 107W, and from 03N to 10N
between 117W and 136W. Scattered moderate convection is noted 
from 08N to 17N between 136W and 140W.
...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Please refer to the Tropical Waves section above for information
on a tropical wave that has a potential for tropical development
offshore Mexico this upcoming weekend, and for related
convection. 
A modest pressure gradient continues across the Gulf of
Tehuantepec area, where the northern portion of a tropical wave 
has just passed by, and is producing strong N to NE gap winds in
the Gulf and downstream to near 14N96W. Seas are 5 to 8 ft across
the area. Across the remainder of the offshore waters of Mexico,
typical ridging has been disrupted by a surface trough from Baja
California Norte to the southwest resulting in a rather weak 
pressure gradient across the region, and mainly light to gentle 
N to NE winds, except moderate from near Cabo Corrientes up the 
coast toward the entrance of the Gulf of California. Seas are 4 
to 6 ft across the waters away from the Gulf of Tehuantepec, and 
1 to 3 ft inside the Gulf of California. An upper level trough
extending offshore of SW Mexico continues to support clusters of
strong thunderstorms along the coasts and nearshore waters of 
western Guerrero and Michoacan, and continue to shift gradually
westward. 
For the forecast, northerly gap winds will continue to pulse to 
strong north winds over the Gulf of Tehuantepec during the
overnight into the early morning hours through the next several 
days, with seas occasionally building to rough. Low pressure 
across Baja California has shifted eastward to along the coast of
mainland Mexico, and will sustain NW to W gap winds across much
of the Gulf of California waters through Fri night before
southerly wind flow returns. High pressure will begin to build
back modestly across the Baja offshore waters Fri afternoon
through Sat night to produce a more typical moderate to fresh NW
wind flow there. Looking ahead, winds and seas are expected to 
build across the outer offshore waters of southwestern Mexico by 
tonight into early next week in association with a developing 
area of low pressure moving by just outside of the offshore 
waters.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, 
AND WITHIN 750 NM OF ECUADOR...
Refer to the Tropical Waves section above for details on any
convection.
Recent satellite scatterometer data shows fresh to strong NE to E 
gap extending across the papagayo region to near 90W, where seas
are 6 to 8 ft. Fresh easterly winds then continue downstream, 
and S of 12.5N, across the outer offshore waters of El Salvador 
and Guatemala, where seas are 6 to 7 ft. Mainly moderate or 
weaker winds are found elsewhere, locally fresh near the border 
of Peru and Ecuador close to the entrance to the Gulf of 
Guayaquil. Seas are 4 to 7 ft across the remainder of the waters 
north of 03N, and 6 to 8 ft south of 03N. Clusters of strong 
thunderstorms are over the waters along and south of Panama to 
offshore Costa Rica, due to the passing tropical wave there, 
described above.
For the forecast, high pressure will persist over the eastern
Gulf of America and northwestern Caribbean into early next week, 
leading to fresh NE to E gap winds pulsing to strong winds over 
the Papagayo region each evening and night. Moderate to fresh 
winds extending well downwind of Papagayo will impact the outer 
waters offshore of El Salvador and Guatemala through at least 
early next week. South of the monsoon trough, winds will 
gradually diminish and remain light to gentle through the
weekend. Mainly moderate seas will prevail away from the Gulf of
Papagayo area through the next several days. Southeasterly swell
producing rough seas across the southern waters will subside
today through Fri.
...REMAINDER OF THE AREA...
Please see the Special Features section and the Tropical Waves 
section above for information on systems that have the potential
for tropical cyclone formation, and any associated convection 
currently present leading to locally higher winds and seas.
High pressure across the NE Pacific extends a ridge south- 
southeastward into the regional waters to offshore of Baja Surf.
Fresh to strong easterly winds and 8 to 10 ft seas associated 
with newly named Tropical Depression Two-C in the Central 
Pacific basin are impacting the waters from 12N to 19N between 
137W and 140W. Moderate to locally fresh trades are found 
elsewhere from 14N to 23N between 128W and 140W. Moderate to 
locally fresh winds are found south of 06N to the east of 120W 
and south of 02N to the west of 120W. Rough seas over the 
southern waters are gradually subsiding, now over the waters 
south of 03N, up to 9 ft south of the Equator and east of 110W.
For the forecast, regardless of tropical development, the 
features described above will bring some increasing winds and 
seas to area waters south of 25N, as they move south of the 
current ridge in place. Away from these features, little change 
is expected in marine weather through the next several days, 
except for the rough seas over the southern waters which are 
forecast to fully subside by the start of the weekend.