Eastern Pacific Tropical Weather Discussion

346
AXPZ20 KNHC 252202
TWDEP
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Tue Aug 25 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
2100 UTC.
...SPECIAL FEATURES...
Tropical Storm Iselle is centered near 21.0N 121.8W at 2100 UTC,
moving west-northwest at 8 kt. Estimated minimum central 
pressure is 994 mb. Maximum sustained wind speed is 50 kt with 
gusts to 60 kt. Peak seas are estimated near 28 ft. Numerous 
moderate isolated strong convection is noted from 21.5N to 24.5N
between 119W and 122W, while scattered moderate convection 
extends elsewhere from 20N to 25N between 118W and 122W. This 
current west- northwest motion is expected to continue through
Wed, while Iselle gradually weakens due to continued westerly 
upper level wind shear and cooler SSTs. Iselle is forecast to 
become a post- tropical remnant low by Thu. S-SW swell generated
by Iselle is affecting the offshore waters and west coast of the
Baja California Peninsula, and will continue through Wed morning
before subsiding quickly. These swells are likely to cause large
and powerful surf and life- threatening rip current conditions. 
Please consult products from your local weather office. 
 
The remnants of Tropical Storm Julio are centered near 21.0N
119.5W at 2100 UTC, moving north at 22 kt. Estimated minimum 
central pressure is 1003 mb. Maximum sustained wind speed is 40
kt with gusts to 50 kt. Peak seas are estimated at 16 ft within 
120 nm across the E semicircle. Numerous moderate isolated  
strong convection is noted in a narrow band from 13N to 20.5N 
between 117.5W and 122W, to the south of the remnants of Julio.
This system is exposed to the north of the area of strong 
convection, and no longer has a closed cyclonic circulation, and 
thus is no longer a tropical cyclone. Recent satellite 
scatterometer data showed winds to 40 kt across the eastern
semicircle of the remnant low of Julio. A Gale Warning is now in
effect for this area of winds through this evening, before the
remnants become absorbed within the outer eastern circulation of
Iselle this evening through tonight.
Please read the latest HIGH SEAS FORECAST issued
by the National Hurricane Center at website -
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest NHC
Forecast/Advisory and Public Advisory at www.hurricanes.gov for 
more details on these two systems.
...TROPICAL WAVES...
A tropical wave is along 110W, from 06N to 20N, moving westward 
at 15 kt. Scattered to numerous moderate isolated strong 
convection is noted from 05N to 15.5N between 99W and 112W.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough extends from 10N75W to 08.5N97W to 08.5N102W
to 13N112W, then resumes SW of Julio from 14N121W to low pres 
near 10N140W 1008 mb. Aside from the convection related to the 
tropical waves, T.S. Julio and T.S. Iselle described above, 
scattered to numerous moderate to strong convection is noted 
from 03.5N to 08.5N E of 91W and from 06N to 13N between 90W and
99W. Scattered to locally numerous moderate isolated strong 
convection is noted from 07N to 12N between 120W and 128W, and 
from 03.5N to 12N between 128W and 143W.
...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Please see the Special Features section for more information
about T.S. Iselle. 
Tropical Storm Iselle continues to move away from the Mexican 
offshore waters, located near 21.0N 121.8W at 2 PM PDT, moving 
west- northwest at 8 kt. Maximum sustained winds are 50 kt with 
gusts to 60 kt, and the minimum central pressure is 994 mb. The
remnants of former Tropical Storm Julio are racing northward and
gradually merging into the easten side of Iselle, located near
21.0N 119.5W at 2 PM PDT. Winds to 40 kt are within 80 nm across
the eastern semicircle and gradually shifting away from the
Revillagigedo Islands this afternoon. The proximity of Iselle 
continues to disrupt the ridge to its north, and into the Baja 
offshore waters. This is maintaining light to gentle winds 
across the Baja California waters and mostly NE to E winds 
across the SW Mexican offshore waters W of Puerto Angel. Seas 
are 7 to 13 ft in S-SW swell from Iselle across the Baja Sur 
waters, and 5 to 8 ft in building S-SW swell across the Baja 
Norte waters. Seas are 4 to 5 ft elsewhere across the remainder 
of the Mexican offshore waters. Winds and seas are gradually 
diminishing across the Revillagigedo Islands and area waters as 
Iselle gradually moves away from that area, as seas are subsiding
to 7 to 10 ft there. Light and variable winds generally dominate
the Gulf of California. A large cluster of strong thunderstorms 
overs the entrance to the Gulf, supported by an upper level low 
pressure system, has shifted northwestward into the southern Gulf
and across Baja Sur in recent hours, and diminished considerably. 
Otherwise, fresh to strong N to NE gap winds persist across the 
Gulf of Tehuantepec and downwind to about 14N with 6 to 8 ft 
seas.
For the forecast, Iselle will continue to move west-northwestward
and away from the area waters, while gradually weakening,
reaching near 21.3N 123.0W tonight, and near 21.8N 124.7W midday
Wed. Large S-SW swell from Iselle will continue to move through 
the Baja waters through early Wed before quickly subsiding. 
Elsewhere, fresh northerly gap winds will continue to pulse to 
strong speeds across Tehuantepec region during the overnight and 
early morning hours through the upcoming weekend, with seas 
occasionally building to 8 ft. Looking ahead, another tropical 
wave and developing low pressure area will follow a similar 
trajectory as Iselle, Thu through the weekend, and impact the 
outer offshore waters near the Revillagigedo Islands within 
increasing winds and seas. A tropical depression could form 
late this weekend or early next week while it moves westward to 
west-northwestward at 10 to 15 mph well offshore of southern 
Mexico.
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, 
AND WITHIN 750 NM OF ECUADOR...
Fresh to locally strong NE to E gap winds continue across the 
Papagayo region and downwind to near 90W, where seas are 6 to 8 
ft. Moderate to locally fresh southerly winds and moderate seas 
are S of 04N and between the Ecuador and the Galapagos Islands. 
Moderate or weaker winds are found elsewhere, with slight to 
moderate seas in SW swell. Scattered to numerous moderate to 
strong thunderstorms have intensified across the eastern waters,  
from 04N to 09.5N between Colombia and 90W, including the 
entrance to the Gulf of Panama, and nearshore waters of western 
Panama, and Cost Rica.
For the forecast, moderate to fresh NE to E gap winds will 
pulse to strong speeds over the Papagayo region each night 
through Sat night building seas to around 8 ft. Moderate to 
fresh winds extending well downwind of Papagayo will impact the 
outer offshore waters of El Salvador and Guatemala through the 
end of the week. South of the monsoon trough, moderate to locally
fresh S winds will diminish to gentle to moderate speeds Tue 
night and then prevail through the remainder forecast period. 
Otherwise, cross- equatorial SW swell will move into the area 
waters Thu night through Fri. 
...REMAINDER OF THE AREA...
Please see the Special Features section for more information about
T.S. Iselle and the remnants of T.S. Julio. 
High pressure of 1021 mb located near 35N129W extends a broad 
ridge south and southeastward to approximately 118W, and drapes 
across Iselle. The pressure gradient between these features and 
low pressure associated with the monsoon trough is supporting 
moderate to locally fresh NE to E winds from 10N to 25N and W of 
125W per recent satellite scatterometer data. Moderate to fresh 
SW to W winds are south of the monsoon W of 130W while moderate 
to fresh E winds accompany the tropical wave near 110W. South of
the monsoon trough and between 116W and 125W, fresh S-SW winds 
are feeding into Julio and the eastern side of Iselle. Elsewhere,
winds are moderate or weaker and seas moderate.
For the forecast, the remnants of Julio will move northward and 
gradually become absorbed in the larger circulation of Iselle
this evening, while Iselle shifts west-northwestward between 20N
and 25N tonight through Wed before dissipating Thu. A tropical 
wave located near 110W, well to the SW of SW Mexico, is 
producing a large area of disorganized showers and thunderstorms.
Environmental conditions appear favorable for development of 
this system, and a tropical depression is expected to form by the
end of the week while it moves generally west- northwestward at 
10 to 15 kt, well offshore of Mexico. This system has a low 
chance for tropical cyclone formation within the next two days 
and high chance of development through 7 days.
Looking ahead, an area of low pressure could form well offshore 
of Central America late this week or this weekend. Environmental 
conditions should support some gradual development of this 
system, and a tropical depression could form late this weekend or
early next week while it moves westward to west-northwestward at
10 to 15 mph well offshore of southern Mexico. This system has a
low chance for tropical cyclone formation within the next two 
days and a medium chance of development through 7 days.