Eastern Pacific Tropical Weather Discussion

025
AXPZ20 KNHC 191548
TWDEP 
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Wed Aug 19 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.
...SPECIAL FEATURE...
The axis of a tropical wave is near 137W, from 17N southward,
moving westward at around 15 kt. 1008 mb low pressure is 
analyzed near the wave at 09.5N136.5W, and has been designated 
Invest EP90. Scattered to numerous moderate to strong convection
is noted from 00N to 14.5N between 130W and 146W. This area of 
active convection is showing some signs of organization. 
Environmental conditions appear conducive for further development
of this system, and a tropical depression is likely to form 
within a few days while the system moves generally westward 
across the western portion of the east Pacific and into the 
Central Pacific. This system has a high chance of tropical 
formation in the next 48 hours.
...TROPICAL WAVES...
The axis of a tropical wave is near 92W from 03N northward to 
Central America, moving westward at around 15 kt. Scattered 
moderate to strong convection is noted from 04.5N to 15.5N 
between 85W and 97W. An area of low pressure is forecast to form
several hundred nautical miles south- southwest of the coast of 
southern Mexico around the end of the week. Gradual development 
of this system is likely thereafter, and a tropical depression is
expected to form this weekend while the system moves generally 
west-northwestward, remaining well offshore of Mexico. This
system has a low chance of tropical development in the next 48
hours. 
The axis of a tropical wave is near 108W south of 17N, moving 
westward at 10 to 15 kt. Scattered moderate convection is noted 
from 04.5N to 13N between 104W and 114W.
The axis of a tropical wave is near 137W, and is described above
in the special features section.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 11N74.5W to 08N91W to 09.5N107W
to 07N126W to 11N136W to low pressure, Invest EP90, near
09.5N136.5W to beyond 08N140W. Other than the convection 
described above with three tropical waves, scattered moderate
convection is noted from 03N to 08.5N E of 84.5W. Scattered 
moderate to strong convection is noted from 09.5N to 15.5N 
between 98W and 104W, and from 03N to 14N between 114W and 130W.
...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.
High pressure across the NE Pacific extends a ridge south-
southeastward into the regional waters to just northwest of the
Revillagigedo Islands. The pressure gradient between this ridge
and low pressure troughing across Baja California is yielding 
moderate NW to N winds across the near and offshore of Baja 
California north of Punta Eugenia, with fresh S to SE winds in 
the northern Gulf of California. Meanwhile, a tight pressure 
gradient over the Gulf of Tehuantepec ahead of an approaching
tropical wave yields strong N to NE gap winds in the Gulf and
extending downstream to near 13N96W. Resultant of 7 to 9 ft are 
present there. Winds are moderate or weaker across the remainder 
of the waters. Seas are 4 to 6 ft across the remainder of the 
offshore waters, and 1 to 3 ft inside the Gulf of California, 
except 4 to 5 ft in northern Gulf where the fresh winds are
occurring. 
Showers and thunderstorms occurring overnight across Baja Sur 
and the adjacent waters have nearly ended as the associated upper
level low center is shifting westward into the cooler Pacific 
waters. Scattered strong thunderstorms are drifting northwestward
to near the coast of Oaxaca and SE Guerrero, as this convection 
interacts with an upper level trough across that area. 
For the forecast, northerly gap winds will continue to pulse to 
strong north winds over the Gulf of Tehuantepec each evening and 
night through the end of the week. Seas will occasionally build 
to rough during periods of strong winds. Low pressure across Baja
California will sustain a southerly wind flow across the Gulf of
California waters, with fresh winds expected across northern 
portions there through midday before gradually diminishing 
through Fri. Winds and seas will diminish modestly across the 
Baja offshore waters through the end of the week as high pressure
weakens. Looking ahead, winds and seas are expected to build 
across the outer offshore waters of southwestern Mexico by Fri 
into the upcoming weekend in association with a developing area 
of low pressure, expected to develop 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.
Fresh to strong easterly gap winds continue across the Papagayo 
region overnight satellite scatterometer data, extending 
downwind to near 92W. Seas there are 6 to 8 ft with these winds.
Winds are moderate or weaker elsewhere north of the monsoon 
trough, and moderate south of the monsoon trough, except fresh 
south of 02S, highest near the entrance of the Gulf of Guayaquil.
Seas across most of the remainder of the waters north of the 
Equator are 4 to 6 ft in mixed cross equatorial S and SW swell, 
and 7 to 9 ft in S to SW swell south of 01N, highest south
through southwest of the Galapagos Islands.
For the forecast, the pressure gradient between high pressure 
over the northwestern Caribbean and relatively lower pressure 
over Central America will lead to fresh NE to E gap winds pulsing
to strong winds over the Papagayo region each evening and night
through the rest of the week and into the weekend, resulting in 
rough seas at times. Moderate to fresh winds extending well 
downwind of Papagayo will impact the outer waters offshore of El 
Salvador and Guatemala through the upcoming weekend. Moderate to
locally fresh southerly winds south of the monsoon trough and 
across the Galapagos waters will gradually diminish tonight 
through Thu. Cross-quatorial SW swell moving into the regional 
waters will continue to merge with larger S to SE swell 
dominating the southern Pacific waters well south of the 
Galapagos to produce rough seas 8 ft and greater south of the 
Equator, and moderate seas elsewhere through Thu before the rough
seas area subsides.
...REMAINDER OF THE AREA...
See Tropical Waves section above for information on two tropical
waves that have potential for tropical development later this 
week and into the upcoming weekend.
High pressure across the NE Pacific extends a ridge south- 
southeastward into the regional waters to just northwest of the 
Revillagigedo Islands. Moderate to locally fresh NE to E winds 
are noted from around 10N to 21N between 124W and 140W. Seas are
6 to 8 ft across these waters with a tropical wave helping to 
enhance conditions there. Moderate to fresh SE to S winds are 
found south of 05N, with winds mainly moderate or weaker across 
the remainder of the waters. Seas are 7 to 10 ft south of 04N in 
mixed cross equatorial swell, and mainly 5 to 7 ft across the 
remainder of the waters, slightly lower in the north- central 
waters right under the ridging. Scattered to numerous moderate to
strong showers and thunderstorms accompany the tropical wave
along 137W, and cover the area from 00N to 14.5N between 130W 
and 146W.
For the forecast, regardless of tropical development, the 
tropical waves described above will bring some increasing winds 
and seas to area waters, as they move south of the current ridge
in place. Away from these waves, little change is expected in 
marine weather through the week and into the upcoming weekend.