061
FXUS66 KSTO 032027
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
127 PM PDT Thu Sep 3 2026

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



.KEY MESSAGES...

  - Well below normal temperatures persist through this week

  - Wet weather continues this week, thunderstorms and scattered
    to widespread showers north of I-80 this afernoon and evening

  - Showers continue on Friday over the Sierra and southern
    Cascades and adjacent foothills

  - Mainly dry Saturday, with some mountain showers Sunday,
    mainly north of I-80

  - There is the potential for some monsoonal moisture mid-next
    week, but confidence in details remains low at this point

&&

.DISCUSSION...

A cold front is traversing Northern California this afternoon,
while the main upper-level trough located over the Northeast
Pacific slowly dig southward. Scattered to widespread showers and
isolated thunderstorms are expected mainly north of I-80 this
afternoon and evening, including the N. Sacramento Valley. An
additional half to an inch of rain is forecast over the west
slopes of Shasta County, with the northern Sacramento Valley
seeing a quarter to half of an inch. Some light showers or
sprinkles are possible (10-15% chances) into the Sacramento Valley
later this evening and into early Friday. In addition, there
continues to be a 15-20% probability of thunderstorms this
afternoon and evening in the mountains north of I-80, highest over
the mountains of Shasta County and western Plumas County. Shower
activity will gradually to taper off from west to east later this
evening, with any lingering showers through Friday.

Troughing will remains the dominant pattern through the weekend,
maintaing cooler than normal temperatures. An upper low spinning
centered over Oregon may have bring some weak disturbances in the
mountains over the weekend, but Saturday has trended dry. On
Sunday the center of the upper low passes along the California and
Oregon border, with slight chance of mainly Shasta County
showers, generally dry elsewhere.

There is still some potential for monsoonal moisture moving into
California next week, but confidence in precipitation potential
from this extending into interior Northern California remains
fairly low and now looks more likely mid next week. Currently the
best potential for rain is over the mountains south of I-80 on
Wednesday, especially in the mountains. Temperatures trend warmer,
to near normal by Wednesday.

&&

.AVIATION...

MVFR ceilings with -SHRA moving along and north of I-80, while
VFR conditions with mid to high level clouds southward. There is a
10% chance of a brief IFR with SHRA/VCTS for KRDD and KRBL
through 00Z/02Z. Lingerings showers are expected to gradually
taper off this evening into Friday. Valley south to west 10 to 15
kts through this afternoon with gusts up to 25 kts and Sierra
gusts up to 30 to 40 kts until 06z Friday with lingering gusts
over the Sierra through 18z Friday.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$