945
AXPZ20 KNHC 162201
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 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 1800 UTC surface analysis and satellite imagery through
2130 UTC.

...SPECIAL FEATURES...

South of Southern Mexico (Invest EP91):
A broad area of low pressure is producing some disorganized
showers and thunderstorms offshore of southern Mexico, generally
from 11N to 16N between 94W and 102W. Environmental conditions
appear conducive for gradual development of this disturbance, and
a tropical depression could form during the next couple of days
or so. The system is forecast to move slowly west-northwestward
or northwestward near the coast of southern and southwestern
Mexico through the weekend. There is a medium chance of tropical
development within the next 48 hours. 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 08N78W to 08N82W to EP91
centered near 12N98W to a 1012 mb low near 07N135.5W to 09N140W.
Scattered moderate convection is occurring from 06N to 13N
between 84W and 90W. Widely scattered convection is noted from
09N to 12N between 100W and 115W.

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

Please read the Special Features section for information on EP91
and the potential tropical development off the coast of southern
Mexico.

Earlier scatterometer satellite data showed fresh to locally
strong N to NE gap winds were occurring in the Gulf of
Tehuantepec as a 1012 mb high prevails over east-central Mexico.
Elsewhere, ridging extends over the Baja California waters,
stemming from a 1031 mb high centered northwest of the area near
37N141W. The pressure gradient between this ridge and a surface
trough extending from northwestern Mexico to 18N107W is
supporting moderate to locally fresh NW winds, as noted via
scatterometer data, and 5 to 8 ft seas over the Baja waters. In
the northern Gulf of California, moderate to fresh NW winds and
2 to 4 ft seas are noted, with gentle to moderate winds and 1 to
3 ft seas occurring in the central and southern Gulf. Mainly
moderate NW winds and 5 to 6 ft seas are noted offshore of
southwestern Mexico.

For the forecast, fresh N to NE winds in the Gulf of Tehuantepec
will diminish through this afternoon. Elsewhere, moderate to
occasionally fresh NW winds and locally rough seas will prevail
offshore of Baja California through Fri morning. Pulsing moderate
to fresh NW winds will also be possible in the northern Gulf of
California through this evening. Looking ahead, a broad area of
low pressure, EP91, is centered offshore of southern Mexico.
Environmental conditions appear conducive for gradual development
of this disturbance, and a tropical depression could form during
the next couple of days or so. The system is forecast to move
slowly west-northwestward or northwestward near the coast of
southern and southwestern Mexico through the weekend. There is a
medium chance of tropical development within the next 48 hours.
Regardless of development, increasing winds and building seas are
possible offshore of southern Mexico through this weekend.

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

Recent scatterometer satellite data showed moderate to locally
fresh SW winds and 5 to 6 ft seas were occurring well offshore
of Guatemala as EP91 prevails offshore of southern Mexico.
Mainly moderate S to SW winds and 4 to 5 ft seas are noted
elsewhere south of the monsoon trough. To the north, light to
gentle winds and 3 to 4 ft seas prevail.

For the forecast, fresh to occasionally strong SW winds and
locally rough seas are expected in association with EP91 well
offshore of Guatemala through Fri night. Otherwise, moderate SW
winds and moderate seas will occur south of the monsoon trough
into early next week, with gentle winds and moderate seas
prevailing to the north.

...REMAINDER OF THE AREA...

A 1031 mb high centered northwest of the area near 37N141W
extends ridging over the eastern Pacific waters north of the
monsoon trough. Moderate to fresh N to NE winds are noted via
scatterometer data in this region, and rough seas of 8 to 9 ft in
N swell are noted north of 15N. Elsewhere, moderate to fresh SW
winds are occurring north of 03N and east of 110W in association
with EP91. Mainly moderate S to SE winds and 5 to 7 ft seas are
occurring elsewhere south of the monsoon trough.

For the forecast, moderate to occasionally fresh N to NE winds
and rough seas will occur north of the monsoon trough into this
weekend as high pressure prevails to the north. Winds will
diminish slightly for the second half of the weekend. A new NW
swell will support rough seas north of 25N Fri night through Sun
morning. Elsewhere, fresh to occasionally strong SW winds and
locally rough seas will occur in association with EP91 north of
03N and east of 110W into early Sat. Looking ahead, increasing
winds and building seas are expected over the northern waters
early next week as a weakening cold front moves southward along
the California coast.

$$
ADAMS