385
AXPZ20 KNHC 160942
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Thu Oct 16 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 0600 UTC surface analysis and satellite imagery through
0930 UTC.

...SPECIAL FEATURES...

South of Southern Mexico (Invest EP91): A broad 1007 mb area of
low pressure is near 12N97W. Disorganized numerous moderate
to strong convection is to its north from 12N to 14N between 95.5W
and 98W. East to southeast winds of 20 kt are to its north to
near 14N, then fresh to strong north to northeast winds are north
of 14N associated with an ongoing Gulf of Tehuantepec gap wind
event. Environmental conditions appear conducive for gradual
development of this disturbance, and a tropical depression could
form during the next couple of days or over the weekend. The
system is forecast to move slowly west-northwestward or
northwestward near the coast of southern and southwestern Mexico
through the weekend. This system has a medium chance of tropical
cyclone formation within the next 48 hours and through the next
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
11N73W westward across northern Panama and to 11N86W to low
pressure near 12N96W 1007 mb, and continues to 09N105W to
11N114W to 09N120w and to 09N123W, where it transitions to the
ITCZ to beyond 09N140W. Scattered moderate to isolated strong
convection is seen from 06N to 10N between 86W-92W, and within
180 nm south of the trough between 93W-95W. Scattered moderate
convection is from 05N to 10N between 81W-86W.

...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 offshore the
coast of southern Mexico with the potential for tropical cyclone
formation.

Broad high pressure is building across the area in the wake of
a recently dissipated cold front. Northwest swell is producing
seas of 6 to 9 ft offshore Baja California Norte. Seas are 5 to 7
ft elsewhere west of 108W. Fresh to strong northwest to north
winds are in the Gulf of Tehuantepec as well as downwind from the
Gulf to near 14N along with seas of 6 to 8 ft. Mostly light to
gentle winds and seas of 4 to 6 ft are elsewhere, with seas of 1
to 3 ft in the Gulf of California north of its entrance.

For the forecast, northwest swell moving through the waters W of
Baja California will gradually subside this morning. Fresh to
strong, northerly gap winds in the Gulf of Tehuantepec will
diminish this afternoon. Meanwhile, a broad area of low pressure,
Invest EP91, is offshore southern Mexico near 12N97W. Environmental
conditions appear conducive for gradual development of this
disturbance, and a tropical depression could form during the next
couple of days or over the weekend. The system is forecast to
move slowly west-northwestward or northwestward near the coast of
southern and southwestern Mexico through 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 offshore
southern Mexico, and about 370 nm southwest of  Guatemala, with
the potential for tropical cyclone formation.

Otherwise, gentle to moderate winds prevail across the offshore
waters, locally fresh south of 06N. Seas are 4 to 6 ft primarily
in long-period south to southwest swell.

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 west 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...

Broad high pressure is building across the area as a cold front
recently dissipated. The related pressure gradient is allowing
for generally gentle to moderate north to northeast winds north
of about 13N and west of 118W. A weak trough is analyzed from
near 18N120W to 11N115W. No significant convection is noted with
the trough. North swell producing seas of 6 to 9 ft is north of
20N as was indicated by an altimeter satellite data pass from
yesterday evening. Seas of 5 to 7 ft in mixed swell are to the
south of 20N.

For the forecast, as high pressure continues to build across the
area, northeast winds will freshen west of about 130W starting
today. The north swell will decay today. Farther south, weak low
pressure is likely to form along the trough just north of the
monsoon trough between 115W and 120W through tonight 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 northwest and west-central portions of the area
maintaining seas to a rough state, with yet another set possibly
arriving early next week.

$$
Aguirre