077
FXUS66 KSTO 152110
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
110 PM PST Sat Nov 15 2025

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

.KEY MESSAGES...

 - Widespread light to moderate precipitation spreads from the
   south late this afternoon through Sunday morning. Less
   widespread precipitation expected Sunday afternoon.
 - A colder system will bring more widespread rain and moderate
   mountain snow Sunday PM into Monday. Breezy southerly winds
   will accompany the system, along with isolated thunderstorms on
   Monday.
 - Drier conditions return Tuesday into Wednesday morning,
   followed by another weather system late Wednesday into Friday.

.DISCUSSION...

...Saturday through Sunday Morning...
Light to moderate widespread precipitation is expected late this
afternoon through Sunday morning as an upper low pushes northward.
Highest precipitation amounts are expected over the eastern
Valley and Sierra foothills/mountains. Forecast precipitation
totals are 0.75-1.00 in the Valley and Delta. Amounts over the
mountains and foothills are generally between 1.00 to 1.75 inches.
Snow levels will start out above 8000 feet before dropping down
to 6500-7500 feet Sunday morning. Breezy southerly winds will
also increase over the weekend with the strongest gusts in the
Delta and northern Sacramento Valley.

...Late Sunday through Early Next Week...
Less widespread precipitation is expected Sunday afternoon as
system exits the area. Then, renewed chances for widespread
precipitation are forecast late Sunday into Monday as colder
weather system drops down from the north. WPC Guidance shows the
latest precipitation totals to be around 0.50-1.00" in the Valley
and Delta, with 1.00-1.50" in the foothills and mountains. This
system will be colder, with snow levels around 6500-7000 feet
Sunday, lowering to around 5500-6000 feet by Monday morning. A
Winter Weather Advisory has been issued for the Sierra and
southern Cascades above 6000 feet from 10 PM tonight through 4 PM
Monday. Total snow accumulations of 4 to 10 inches are
anticipated above 6000 feet with 1 to 2 feet at the highest
peaks. Additionally there is a 10 to 20% chance of isolated
thunderstorms Monday afternoon. Breezy southerly winds are also
expected with this system, with forecast gusts between 25 to 35
mph. The strongest winds are expected across portions of the
northern Sacramento Valley, Delta, and the Sierra.

...Mid to Late Next Week...

Drier conditions are expected Tuesday through Wednesday morning.
Another system may approach the region Wednesday evening into
Friday, potentially bringing widespread precipitation and
mountain snow. However, high uncertainty remains regarding
potential storm track and precipitation totals.

.AVIATION...
VFR conditions until around 05z in the northern San Joaquin
Valley as a weather system moves in from the south. Conditions
gradually deteriorate northward in the evening/night hours as rain
overtakes most of the area. MVFR/IFR conditions with southerly
wind gusts up to 25 knots in the Valley; 35 knots in the Delta.
Snow levels around 6500 feet in the mountains Sunday morning with
20-30 knot southerly wind gusts.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 10 PM this evening to 4 PM PST
Monday for West Slope Northern Sierra Nevada-Western Plumas
County/Lassen Park.

&&

$$