882
AXPZ20 KNHC 300125
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Tue Sep 30 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 0000 UTC surface analysis and satellite imagery through
0100 UTC.

...SPECIAL FEATURES...

Well South of the Baja California Peninsula (Invest EP98):
Showers and thunderstorms associated with a small area of 1008 mb
low pressure far to the south of the southern tip of the Baja
California Peninsula near 09.5N112.5W have not improved in
organization since earlier today. Scattered moderate convection
is noted from 05N to 14N between 112W and 120W. Winds are
currently 20-30 kt with seas of 8-10 ft. Environmental conditions
remain favorable for development of this system and a tropical
depression is likely to develop during the next day or so as the
low drifts slowly northward or northwestward well off the coast
of Mexico. This system has a high chance of tropical cyclone
formation through the next 7 days. Please read the latest
TROPCIAL WEATHER OUTLOOK issued by the National Hurricane Center
at website - https://www.nhc.noaa.gov/text/MIATWOEP.shtml for
more details.

...TROPICAL WAVES...

A tropical wave is noted near 112.5W S of 16N. Refer to the
Special Features above for more details, including convection.

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

The monsoon trough axis extends from near the Gulf of Papagayo at
11N86W to 13.5N98.5W to low pressure, Invest EP98, near
09.5N112.5W to 06N123W, then resumes SSE of the remnant low of
Narda from 14N123W to 11N133.5W. The ITCZ extends from 11N133.5W
to beyond 10.5N140W. Scattered moderate convection is noted
from 05N to 10N between 80W and 90W, and from 08.5N to 14N
between 92W and 106W. Similar convection is noted along the coast
from 10N to 16N.

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

Please refer to the Special Features for details on a tropical
wave near 112.5W, Invest EP98, with a high chance of tropical
cyclone formation.

Moderate to locally fresh NW to N winds are noted between 109W
and 114W, from nearshore Baja California S of 30N to beyond the
Revillagigedo Islands and into Invest EP98, as well as in the
southern Gulf of California. Winds are moderate or weaker across
the remainder of the offshore waters, including in the central
and northern Gulf of California. A surface trough is analyzed
from 20N109W to 13.5N110.5W, with scattered moderate convection
within 120 nm of the trough, mainly on the W side. Seas are 6-8
ft W of 110W in mixed SW and NW swells, including offshore Baja
California, and 5-7 ft elsewhere, in mixed S-SW and W-NW swells.
Seas are 3 ft or less in the Gulf of California.

For the forecast, a narrow ridge will continue between the
remnants of Narda and Invest EP98. This pattern will produce
moderate to locally fresh NW to N winds from near Punta Eugenia
southward across the Revillagigedo Islands through Tue, before
becoming confined from Cabo San Lazaro northward. Those winds
will persist into the upcoming weekend under a modest ridge.
Moderate to fresh N winds will pulse in the Gulf of Tehuantepec
through the next several days. Locally rough seas offshore Baja
California will subside to moderate by early Tue. A set of NW
swell will arrive offshore Baja California Thu, building seas to
rough through Sat night. Invest EP98 is forecast to remain just
beyond the offshore waters. Looking ahead, an area of low
pressure is expected to develop off the coast of southwestern
Mexico late this week. Environmental conditions are forecast to
be conducive for additional development of the system thereafter
and a tropical depression could form by early next week as the
system moves generally west-northwestward, just offshore of the
coast of southwestern Mexico.

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

A weak pressure pattern persists over Central America and the
western Caribbean Sea, and is promoting mostly light and variable
winds N of the monsoon trough, which is located just offshore of
Central America from the Gulf of Papagayo west-northwestward.
Moderate SW-W winds prevail S of the monsoon trough. Seas are
5-7 ft in S-SW swell across the waters. Scattered convection is
noted near the coasts and extending southward across the offshore
waters as described above, possibly leading to locally higher
winds and seas.

For the forecast, mostly light to gentle winds will continue N
of the monsoon trough, with brief surges to moderate to locally
fresh early Wed and early Thu. Gentle to moderate S to SW winds
S of the monsoon trough through midweek, freshening thereafter.
Southerly swell will gradually subside into Tue, then building
slightly toward the end of the week and upcoming weekend as winds
freshen.

...REMAINDER OF THE AREA...

Please refer to the Special Features for details on a tropical
wave near 112.5W, Invest EP98, with a high chance of tropical
cyclone formation.

The 1009 mb remnant low of Post-Tropical Cyclone Narda is
located near 22N124W as seen on conventional satellite imagery.
No deep convection is present with this remnant low. A band of
winds around 20 kt currently wrap around the W and into the S
side of this low, with subsiding seas of 7-9 ft. An area of 7-9
ft NW swell is over the NW waters having accompanied a now
dissipated cold front. Seas are mainly 5-8 ft elsewhere. Winds
are mainly moderate or weaker across the open waters away from
the remnant low of Narda and Invest EP98, locally fresh S of the
monsoon trough.

For the forecast, the remnant low of Narda will drift W-SW and
gradually spin down, and open up into a trough by midweek with
associated and residual winds and seas subsiding through then.
Other than the possible tropical cyclone development with Invest
EP98, northerly swell moving S of 30N and E of 130W will
continue to mix with swells from Narda, resulting in confused
seas N of 15N through Tue night before subsiding. A new front or
frontal trough and northerly swell will impact the northern
waters midweek, with associated swell spreading eastward to near
Baja California through the end of the week. High pressure
will to the NW of the area will build southeastward into the NW
waters behind the next front, with moderate to locally fresh N
to NE winds gradually expanding there. Looking ahead, winds will
increase to fresh to locally strong S of the monsoon trough,
mainly E of 125W by the end of the week into the weekend,
building seas to rough S of it. Meanwhile, a new set of large
southerly swell will propagate toward the Equator during the
upcoming weekend.

$$
Lewitsky