000
AXPZ20 KNHC 202137
TWDEP
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 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 1800 UTC surface analysis and satellite imagery through
2030 UTC.
...TROPICAL WAVES...
The axis of a tropical wave is moving over eastern portions of
the Tropical Pacific basin along 84W, north of 04N, moving
westward at 15 to 20 kt. Scattered to numerous moderate to strong
convection is noted from 03.5N to 11.5N E of 87W.
The axis of a tropical wave is near 99W, from 05N to 18N, moving
westward at 10 to 15 kt. Scattered to numerous moderate to
strong convection stretches from 06.5N to 16.5N between 92W and
107W, as the wave interacts with a middle level trough extending
off the SW coast of Mexico. Environmental conditions appear
favorable for gradual development, and a tropical depression is
likely to form this weekend or early next week while the system
moves west-northwestward or northwestward, remaining well
offshore of Mexico.
The axis of a tropical wave is near 113W from 05N to 17N, moving
westward at 10 to 15 kt. An area of low pressure associated with
this tropical wave near 089.5N113W is producing scattered to
numerous moderate to strong convection from 04N to 14N between
109W 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 development, and a tropical depression could form
over the weekend while the system moves west-northwestward or
northwestward at 5 to 10 mph.
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 10N74.5W to 08.5N87W to 09N105W
to 1008 mb low pressure near 08.5N113W to 06N124W to 07N140W.
Other than the convection described above with three tropical
waves, scattered moderate isolated strong convection is noted
from 06N to 14N between 87W and 109W, and from 03N to 11N
between 117W and 137W. Scattered moderate convection is noted
from 13N to 17N between 137W 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 moved W of the Gulf, and is producing strong N to NE gap
winds in the Gulf and downstream to near 13N98W. Seas are 5 to 8
ft across that area. Across the remainder of the offshore waters
of Mexico, typical ridging has been disrupted by a low level
trough offshore of Punta Eugenia, along about 118W, resulting in
a rather weak pressure gradient across the region. Midday
satellite scatterometer data showed that this current pattern is
producing mainly light to gentle NW to N winds, except moderate
near Cabo Corrientes. Seas are 4 to 5 ft across the waters away
from the Gulf of Tehuantepec. Gentle southerly winds prevail
across the far northern Gulf of California, and become gentle NW
to N across the remainder of the Gulf. Seas there are 1 to 3 ft.
An upper level trough extending offshore of SW Mexico continues
to support clusters of strong thunderstorms along the coasts and
nearshore waters of Guerrero and Michoacan, and continue to shift
gradually westward, ahead of an approaching tropical wave.
For the forecast, fresh northerly gap winds will continue to
pulse to strong 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. 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. Southerly wind flow will
return to the Gulf of California Sat night and become fresh to
locally strong Sun. Winds and seas are expected to build across
the outer offshore waters of southwestern Mexico tonight into
early next week in association with a developing area of low
pressure moving westward and 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 westward and
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 6 ft across the remainder of the
waters north of 04N, and 6 to 8 ft south of 04N. Clusters of
strong thunderstorms are over the waters south of Panama and
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
this evening 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 Tropical Depression Two-C in the Central Pacific basin are
impacting the waters from 10N to 19N between 138W and 140W.
Moderate to locally fresh trades are found elsewhere from 10N to
22N between 124W and 140W , where seas are 5 to 7 ft. Moderate
to locally fresh winds are found south of 06N to the east of 118W
and south of 04N to the west of 120W. Rough seas over the
southern waters are gradually subsiding, and now cover the
waters south of 02.5N east of 120W.
For the forecast, regardless of tropical development, the
features described above will bring 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.
$$
Stripling