968
ABPZ20 KNHC 132330
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
500 PM PDT Sat Sep 13 2025

For the eastern and central North Pacific east of 180 longitude:

South of Baja California Peninsula:
An area of low pressure located south of the Baja California
Peninsula, which includes the remnants of Mario, is producing a
broad area of disorganized showers and thunderstorms.
Environmental conditions are expected to be conducive for gradual
development, and a tropical depression could form by the middle of
next week as it tracks slowly westward.
*Formation chance through 48 hours...low...10 percent.
*Formation chance through 7 days...medium...40 percent.

Off the Coast of Southwestern Mexico:
An area of low pressure could develop well offshore of the coast of
southern or southwestern Mexico early next week. Environmental
conditions are expected to be conducive for gradual development as
the low tracks westward to west-northwestward around 10 to 15 mph.
*Formation chance through 48 hours...low...near 0 percent.
*Formation chance through 7 days...low...20 percent.

South and Southeast of the Hawaiian Islands:
An area of low pressure well southeast of the Hawaiian Islands is
producing a large area of disorganized showers and thunderstorms.
Environmental conditions appear conducive for some gradual
development of this system as it moves westward or
west-northwestward at around 10 mph.
*Formation chance through 48 hours...low...near 0 percent.
*Formation chance through 7 days...low...20 percent.

$$
Forecaster Beven

534
AXPZ20 KNHC 132201
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sat Sep 13 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.

...TROPICAL WAVES...

The axis of a tropical wave is along 89W, from 02N northward
through western Honduras into the Yucatan Peninsula. The wave is
moving westward around 15 to 20 kt. Convection associated with
this wave is described in the ITCZ/monsoon trough section below.

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

The monsoon trough axis extends from 08.5N78.5W to 08N82W to
15N117W to 13N140W. Scattered moderate to isolated strong
convection is noted from 06N to 10N east of 90W, from 07N to 13N
between 93W and 99W, from 08N to 22N between 105W and 119W, and
from 10N to 15N between 121W and 140W.

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

Recent scatterometer satellite data show fresh to strong SE to
NE winds and moderate seas are occurring off the coast of Jalisco
near the remnant low of Tropical Storm Mario, analyzed near
18.5N107.5W. Elsewhere, moderate to fresh N to NE winds extend
through the Gulf of Tehuantepec as high pressure builds over
east-central Mexico. Offshore of Baja California, the pressure
gradient between a surface trough over northwestern Mexico into
the central Gulf of California and high pressure to the west is
supporting moderate NW winds and 5 to 7 ft seas, as noted on
recent scatterometer and altimeter data. Gentle to moderate winds
and 1 to 3 ft seas prevail in the Gulf of California.

For the forecast, moderate to locally fresh winds are expected
offshore of west-central Mexico and near the Revillagigedo
Islands this weekend as the remnants of former Tropical Storm
Mario slowly dissipate. Elsewhere, fresh to locally strong N to
NE winds will pulse in the Gulf of Tehuantepec tonight into early
Sun. Moderate to occasionally fresh NE winds are expected
thereafter, with winds increasing to strong speeds by the middle
of next week. Moderate to fresh NW winds offshore of Baja
California will occur through tonight before diminishing slightly
Sun into next week. Looking ahead, an area of low pressure
located south of the Baja California Peninsula is expected to
encounter environmental conditions conducive for gradual
development, and a tropical depression could form by the middle
of next week as it tracks slowly westward. There is a low chance
of formation within the next 48 hours, and a medium chance in the
next 7 days. Elsewhere, an area of low pressure could develop
well offshore of the coast of southern or southwestern Mexico
early next week. Environmental conditions are expected to be
conducive for gradual development as the low tracks westward to
west-northwestward around 10 to 15 mph. There is a low chance of
development within the next 7 days.

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

Moderate to locally fresh S winds are occurring south of the
monsoon trough, with gentle to locally moderate winds noted to
the north, as observed via a recent scatterometer pass. Seas of
5 to 7 ft seas prevail over the regional waters, with seas to 8
ft noted south of the Galapagos Islands.

For the forecast, a long-period Southern Hemisphere swell will
move through the Central and South American waters this weekend,
leading to rough seas offshore of Ecuador by this evening, and
offshore of Colombia through Costa Rica Sun into early next week.
Seas will slowly subside region-wide into Tue, though rough seas
may prevail between the Galapagos Islands and Ecuador through
midweek. Otherwise, moderate to occasionally fresh S to SW winds
will prevail south of the monsoon trough. Looking ahead,
occasional moderate NE gap winds will be possible in the Gulf of
Papagayo by the middle of next week.

...REMAINDER OF THE AREA...

Ridging dominates the eastern Pacific waters north of the
monsoon trough, with gentle to locally moderate N to NE winds
found north of 25N and west of 130W. A moderate pressure gradient
between this ridge and the monsoon trough is supporting moderate
to fresh NE winds farther south and to the west of 115W, as
observed via scatterometer data. Recent altimeter data show 5 to
7 ft seas in this region, with locally rough seas noted from 05N
to 10N west of 135W. Elsewhere, a long-period Southern Hemisphere
swell is supporting 8 to 9 ft seas south of the equator.
Moderate to locally fresh S to SE winds and 5 to 7 ft seas
prevail elsewhere south of the monsoon trough.

For the forecast, a long-period Southern Hemisphere swell will
propagate northward this weekend, supporting rough seas south of
05N between 90W and 120W by tonight, and south of 15N on Sun.
Rough seas will diminish south of 05N early next week, with rough
seas persisting farther north through the middle of next week.
Elsewhere, fresh to locally strong winds are expected within 120
NM on both sides of the monsoon trough and ITCZ generally between
105W and 130W Sun through early next week. Otherwise, moderate
to locally fresh winds are expected elsewhere in the trade wind
waters.

$$
ADAMS