697
FXUS66 KSTO 152201
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
201 PM PST Sun Nov 15 2026

For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.

.KEY MESSAGES...

 - A storm system will continue to bring widespread Valley/foothill
   rain, mountain snow, and breezy southerly Winds through
   monday; not as impactful as recent system.

 - Winter Weather Advisory in effect from 4 PM today through 10
   PM Monday for the Sierra and Lassen Volcanic National Park
   above 6000 feet.

 - Colder, and much wetter weather storm system Tuesday night into
   Friday morning will bring widespread rain, heavy mountain
   snow, and strong, gusty southerly winds.

 - Winter storm watch in effect for elevations above 4000 feet for
   the northern sierra and southern cascades from 10 PM Tuesday
   through 4 AM Friday, and for the Coast Range and Shasta County
   mountains from 7 PM Tuesday through 4 AM Thursday.

&&

.DISCUSSION...

...Today...
Latest radar imagery shows widespread precipitation spreading
across Valley, foothill, and mountain locations north of I-80
this afternoon as a weather system moves across the area. This
system will continue to bring widespread rain, mountain snow, and
breezy southerly winds. Observed precipitation amounts so far
have ranged from 0.25 to 0.75 inches across the northern
Sacramento Valley, with up to 1.25 inches over the mountains.
Additional precipitation amounts will range from around 0.25 to
1.25 inches in the valley, and 1.5 to 2.25 inches the mountains.
Heaviest period of rain is expected Sunday night, with lingering
showers into Monday evening. Precipitation is expected to reach
the I-80 corridor and continue to spread southward later this
afternoon and evening. Periods of breezy southerly winds are
expected through this afternoon. Peak wind gusts so far have
ranged from 20 to 30 mph, with the strongest gusts across the
northern Sacramento Valley and nearby foothills. Some Hi-Res
models suggest the potential for isolated thunderstorms across
portions of the northern Sacramento Valley and the northern San
Joaquin Valley on Monday (10% probability).

Snow levels between 6500-7500 feet are expected today, lowering
To around 5000-6000 feet monday. Total snowfall accumulations of
2 to 8 inches are expected above 6000 feet, with up to 16 inches
at and near lassen volcanic national park. There is the potential
for minor accumulations down to around 5500 feet, possibly a
dusting down to 5000 feet. This will bring slippery roads and
reduced visibilities at times, with possible mountain travel
delays and chain controls. The heaviest snow is expected late
tonight through Monday morning, then gradually diminishing Monday
evening. A Winter Weather Advisory continues for elevations above
6000 feet for the northern Sierra and Lassen Park from 4 PM today
through 10 PM Monday.

...Tuesday...
Dry weather returns by early morning Tuesday. With potentially
clear skies behind the departing system, cold morning lows are
forecast on Tuesday, with mid 30s across the northern Sacramento
Valley and teens to low 30s in the mountains. This could bring the
potential for morning frost, especially over the northern
Sacramento Valley and the foothills. Afternoon highs will be in
the 50s to low 60s in the valley and foothills, with 30s and 40s
over the mountains.

...Tuesday Night - Friday Morning...
After the brief lull during the day Tuesday, confidence is now
high in a colder, wetter system arriving Tuesday night through
early Friday morning that will bring widespread rain, gusty
southerly winds, and heavy mountain snow. While there is still
some uncertainty in exact precipitation amounts, the latest
precipitation forecast indicates 1.25 to 2 inches in the Valley
and Delta, 1.50 to 2.75 inches in the foothills , and 2 to 3.35
inches over the mountains. Thunderstorms are also possible on
Wednesday and Thursday (10-20%), which could bring locally heavy
rain, small hail and gusty outflow winds. Ponding of water on
roads and elevated small streams are possible as well. At this
point, best thunderstorm chances appear to be later Wednesday into
Thursday.

Snow levels initially start around 3500-4500 feet Tuesday night,
then rise to around 4500-6000 feet by late Wednesday morning.
Total snow accumulations between 1 and 2 feet above 5000 feet are
possible in the Sierra and southern Cascades, with up to 3 feet
at the highest peaks. Total snow accumulations of 4 to 8 inches
are expected between 4000 feet to 5000 feet, with up to 12 inches
at 5000 feet. The heaviest snow is expected Wednesday afternoon
and evening, with snowfall rates up to 1-2+ inches per hour. A
Winter Storm Watch is in effect for elevations above 4000 feet
for the northern Sierra and southern Cascades from 10 pm Tuesday
through 4 AM Friday, and for the Coast Range and Shasta County
mountains from 7 pm Tuesday through 4 AM Thursday. Mountain
travel could be very difficult to impossible Tuesday night through
early Friday morning. Gusty winds could bring down tree branches
and significant reductions in visibilities.

While there is still some uncertainty regarding wind gusts, strong
southerly winds look to develop late Tuesday night and continue
through the day thursday. Latest forecast suggests wind gusts
ranging from 35 to 45 mph in the Valley, Delta, and foothills.
These winds will bring the potential for downed trees, local power
outages, and difficult driving conditions. We will continue to
monitor trends on this mid to late week system, especially as
recent trends are leaning towards a stronger storm. Make sure to
keep checking the forecast for updates as we move through the
weekend and into early next week. There is the potential for an
active weather pattern to continue into thanksgiving week.

&&

.AVIATION...

VFR conditions with MVFR/IFR ceilings and/or visibilities at TAF
sites through 18Z Monday and periods of RA and BR. Southerly
winds 10-15 kts with gusts 15-25 kts through 00Z Monday then
decreasing. Southwest wind gusts over the Sierra Crest 35 to 45
kts through 18Z Monday along with mountain MVFR/IFR/LIFR
conditions in RA/SN.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Tuesday evening through late Wednesday
night for E. Shasta /S. Cascades Above 3000 ft-Glenn/Colusa
Coast Range Above 3000 ft-Lassen Volcanic NP-Sierra (Cal-Tuo)
3000-5000 ft-Sierra (Cal-Tuo) Above 5000 ft-Sierra (El Dorado-
Amador) Above 5000 ft-Sierra (Sierra-Placer) Above 5000 ft-
Sierra (Tehama-Plumas) Above 3000 ft-Sierra (Yuba-Placer) 3000-
5000 ft-Sierra 3000-5000 ft-Tehama Co Coast Range Above 3000 ft-
W. Shasta County Above 3000 ft.

Winter Weather Advisory until 10 PM PST Monday for Lassen
Volcanic NP-Sierra (Cal-Tuo) Above 5000 ft-Sierra (El Dorado-
Amador) Above 5000 ft-Sierra (Sierra-Placer) Above 5000 ft.

&&

$$