804
AXPZ20 KNHC 151522
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Wed Oct 15 2025

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 FEATURES...

South of Southern Mexico (Invest EP91): A broad 1007 mb area of
low pressure near 12.5N94.5W is producing some disorganized
showers and thunderstorms offshore of southern Mexico and
portions of Central America. Scattered moderate isolated strong
convection is noted within 180 nm in the NE semicircle. Some
fresh to near gale-force winds are nearby, but associated with a
plume of gap winds from the Gulf of Tehuantepec where seas are
also 7-9 ft. Environmental conditions appear conducive for
gradual development of this disturbance, and a tropical
depression could form late this week or over the weekend. The
system is expected to move little during the next couple of days,
but a slow northwestward motion near the coast of southern and
southwestern Mexico is expected by the weekend. Regardless of
development, expect the potential for increasing winds and
building seas. This system has a medium chance of tropical
cyclone formation within 48 hours and 7 days. Please refer to the
latest NHC Tropical Weather Outlook at www.hurricanes.gov for
more details.

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

The monsoon trough axis extends from northern Colombia near
10N75.5W to across the SW Caribbean Sea and southern Nicaragua to
the Pacific coast near 11.5N86.5W to 1007 mb low pressure,
Invest EP91, near 12.5N94.5W to 10N100W to 12N110W to 06N123W to
11N140W. Isolated to widely scattered moderate convection is
noted from 02N to 09N between 77W and 90.5W, and from 05N to 15N
between 96W and 106W. Similar convection is near the coast of SW
Mexico within 180 nm of shore between 100W and 106W.

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

Please read the Special Features section above for information on a
broad area of low pressure, Invest EP91, that is near the coast of
southern Mexico with the potential for tropical cyclone
formation.

A weakening cold front extends from SW Arizona to across Baja
California Norte near 32.5N114.5W to offshore and 25.5N123.5W
continuing to 27.5N138W. Broad high pressure is building in the
wake of the front. NW-N moderate to locally fresh winds are found
even out ahead of the front as the high bridges across, with
these winds W of 109W or so. Associated NW swells are arriving
offshore Baja California Norte with seas of 7-10 ft there. Seas
are 5-7 ft elsewhere W of 109W. Fresh to near gale-force N-NE
winds are in and downwind of the Gulf of Tehuantepec with seas of
6-9 ft. Mainly light to gentle winds and 4-6 ft are elsewhere,
with seas of 2-4 ft in the Gulf of California.

For the forecast, NW swell moving through the waters west of
Baja California will gradually subside through Thu morning. Fresh
to strong, locally near gale-force today, northerly gap winds
will persist in the Gulf of Tehuantepec through early Thu
afternoon. Meanwhile, a broad area of low pressure, Invest EP91,
is near the coast of southern Mexico. Environmental conditions
appear conducive for gradual development of this disturbance,
and a tropical depression could form late this week or over the
weekend. The system is expected to move little during the next
couple of days, but a slow northwestward motion near the coast of
southern and southwestern Mexico is expected by the weekend.
Regardless of development, expect the potential for increasing
winds and building seas.

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

Please read the Special Features section above for information on a
broad area of low pressure, Invest EP91, that is near portions of
the coast of Central America, with the potential for tropical
cyclone formation.

Otherwise, gentle to moderate winds prevail across the offshore
waters, except gentle nearshore from Panama to Nicaragua. Seas
are 4-6 ft in mixed swells. Active convection is noted across the
waters as described above with locally higher winds and seas
possible.

For the forecast, in association with the Special Features
broad area of low pressure, expect increasing winds and building
seas, mainly W of the offshore waters of Guatemala. Winds may
freshen south of the monsoon trough as it lifts northward through
the remainder of the week, which could lead to a slight build up
of seas. Expect tranquil marine conditions across the waters late
in the weekend into early next week.

...REMAINDER OF THE AREA...

A weakening cold front extends from SW Arizona to across Baja
California Norte near 32.5N114.5W to offshore and 25.5N123.5W
continuing to 27.5N138W. Broad high pressure is building in the
wake of the front. Moderate to locally fresh winds are found
behind the front, with gentle to moderate winds elsewhere N of
the monsoon trough and ITCZ. Winds are moderate S of the monsoon
trough and ITCZ, except to fresh E of 110W to the S of the axis
and N of 04N. For seas, northerly swell of 7-11 ft associated
with the front are found N of 24N, with 5-7 ft seas in mixed
swells S of 24N and W of 110W. Seas are slightly lower overall
to the E of 110W.

For the forecast, the cold front will gradually decay to a
remnant frontal trough by early Thu, then dissipate by the end of
the week. Winds will locally freshen behind the front as high
pressure builds in across the area. Rough northerly swell in the
northern waters will continue to press southward through Thu
while decaying. Farther S, weak low pressure is likely to form
along the monsoon trough between 115W and 120W through Thu night
as depicted in the global models. Looking ahead, a reinforcing
set of long-period northwest swell may arrive by the end of the
week into the weekend over the NW and W-central portions of the
area maintaining seas to a rough state, with yet another set
possibly arriving early next week.

$$
Lewitsky