463
AXPZ20 KNHC 170247
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Mon Aug 17 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 0000 UTC surface analysis and satellite imagery through
0250 UTC.

...SPECIAL FEATURES...

Heavy Rainfall in Panama and Colombia: A tropical wave, currently
analyzed in the central Caribbean Sea near 75W, will cross
Panama and northern Colombia through Mon, interacting with the
monsoon trough and combining with enhanced divergence aloft to
induce thunderstorms, particularly over the Darien region of
Panama and the Choco-Colombia. Heavy rainfall from these
thunderstorms may lead to flooding.

...TROPICAL WAVES...

The axis of a tropical wave is along 95W from the Gulf of
Tehuantepec southward to the Equator, moving quickly westward
around 25 kt. An area of low pressure could form several hundred
nautical miles south of the coast of southern Mexico around the
middle part of the week. Nearby convection is discussed in the
ITCZ/monsoon trough section below.

The axis of a tropical wave is near 121W from 17N southward,
moving quickly westward around 25 kt. Nearby convection is
discussed in the ITCZ/monsoon trough section below. A broad
area of low pressure could form well to the southeast of the
Hawaiian Islands during the middle to latter part of the week.

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

The monsoon trough extends from 1006 mb low pressure over
northern Colombia at 11N74W to near the Gulf of Papagayo at
10N86W to 07N97W to 08N102W. The ITCZ extends from 08N102W to
08.5N121W, then resumes west of a tropical wave from 09N123W to
05N140W. Scattered to numerous moderate and isolated strong
convection is noted from 02N to 14.5N between 77W and 108W, from
06N to 11N between 108W and 130W, and from 01N to 06N between
138W and 140W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

See Tropical Waves section above for information on a tropical
wave that has a potential for tropical development offshore
southern Mexico next week.

Strong to near gale north gap winds are over the Gulf of
Tehuantepec. Fresh northwest winds are near the Pacific coast of
Baja California, locally strong near and north of Punta Eugenia.
Elsewhere, winds are moderate or weaker. Seas are 6 to 8 ft over
the Gulf of Tehuantepec, 5 to 7 ft over the remaining open
Pacific offshore waters, and 1 to 3 ft over the Gulf of
California. Scattered moderate convection is noted in the
offshore waters from Guerrero southward.

For the forecast, the pressure gradient between high pressure
over the Gulf of America and relatively lower pressure south of
Mexico will continue to induce pulses of strong north winds over
the Gulf of Tehuantepec through Wed night, with moderate to
fresh pulses thereafter. Winds will reach reach near gale force
at times tonight, Mon night and Tue nights, while resultant rough
seas are also expected. Fresh northwest winds are forecast off
of the Baja California peninsula through Tue night, with winds
reaching strong speeds near Punta Eugenia. Meanwhile, a surge of
strong SE winds may move from near Cabo Corrientes up across the
Gulf of California Mon night into early Tue, likely associated
with a complex of convection.

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

See Special Features section above for information on heavy
rainfall that may cause flooding over the next few days in
portions of Colombia and Panama.

Fresh to strong northeast to east gap winds are over the
Gulf of Papagayo region. Seas generated from earlier slightly
stronger winds have propagate well away from the source region
to the south of 11N and west of 90W. Elsewhere, winds are
moderate or weaker north of the monsoon trough, and moderate to
fresh south of the monsoon trough. Seas are 4 to 7 ft in long-
period southwest swell over the remainder of forecast waters,
except to 8 ft south of the Galapagos Islands. Thunderstorms are
present near the monsoon trough as described above across much of
the offshore waters, with locally higher winds and seas possible
near any convection.

For the forecast, the pressure gradient between high pressure
over the western Caribbean and relatively lower pressure over
Central America will lead to fresh northeast to east gap winds
over Papagayo region, locally strong to near gale-force at times
with occassionally and locally rough seas as a result. Moderate
to fresh winds will extend away from this area across the far
offshore waters of El Salvador and Guatemala midweek. Moderate to
fresh southerly winds will pulse south of the monsoon trough
into Mon night. Large southerly swell will impact waters mainly
from Ecuador to the Galapagos Islands through the next several
days, largest expected through Wed.

...REMAINDER OF THE AREA...

The low pressure associated with the remnants of Hernan is
opening to a surface trough located just west of the discussion
area and 140W. Some residual associated rough seas are along and
just east of 140W from 16N to 22N. Another weak developing
surface trough is just northeast, from near 25N132W to 20N135W.
Moderate to fresh winds are found from 23N to 28N between 128W
and 138W. Scattered moderate isolated strong convection is noted
on satellite imagery from 17N to 30N between 125W and 133W. Some
moderate to fresh winds are noted from 09N to 17N between 115W
and 129W near a tropical wave described above. Moderate to fresh
SE to S winds are found south of 02N and east of 126W. Winds are
moderate or weaker across the remainder of the open waters.
Seas are 7 to 9 ft in mixed SE and SW swell south of the Equator
and west of 90W, and also elsewhere south of 03N between 110W
and 130W.

For the forecast, winds and seas associated with the remnants of
Hernan will diminish later tonight toward 140W. Rough seas will
prevail along and south of the Equator through the middle of the
week. An area of low pressure could form several hundred nautical
miles south of the coast of southern Mexico around the middle
part of the week. Gradual development of this system is possible
thereafter, and a tropical depression could develop towards the
end of the week or next weekend while the system moves west-
northwestward, while staying south of Mexico. In addition, a
broad area of low pressure could form well to the southeast of
the Hawaiian Islands during the middle to latter part of the
week. Environmental conditions appear conducive for gradual
development of this system, and a tropical depression could form
towards the end of the week and into the weekend, while the
system moves generally westward across the western portion of the
east Pacific and into the central Pacific. Regardless of
development, expect some increasing winds and seas with this
area.

$$
Lewitsky