810
FXUS66 KSTO 111858
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1158 AM PDT Fri Sep 11 2026

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

.KEY MESSAGES...

  - Renewed fire weather conditions over the weekend and into
    early next week due to gusty winds and low daytime humidity

  - Red Flag Warning in place for portions of northern California
    from 11 AM PDT Saturday through 11 AM PDT Monday

  - Notable cool down over the weekend, with near to below normal
    temperatures expected

&&

.DISCUSSION...

Today-Monday:
Mostly clear skies observable today, though as onshore flow
increases and the ridging of the past few days breaks down,
temperatures are expected to be a bit cooler today than earlier
this week. Highs today will still be above normal, with Valley
temperatures in the low to mid 90s. Further cooling will occur
Saturday as a low progresses inland over the Pacific Northwest.

Breezy southerly winds begin this afternoon, with strongest gusts
today expected in and near the Delta and over the Sierra Crest.
On Saturday, winds will pick up further, with gusts of 25 to 35
mph expected by the late morning/early afternoon. Combined with
lingering higher than normal temperatures and low daytime
humidities, we`re expecting elevated fire weather conditions in
much of northern California. In particular, the northern half of
the Sacramento Valley and portions of the northern foothills will
see critical fire weather conditions, and so a Red Flag Warning is
in place starting Saturday at 11 AM PDT and ending on Monday at
11 AM PDT. Winds will be strongest on Saturday and Sunday
afternoons and evenings, with slightly weaker winds in the morning
on Sunday as they transition in direction from south and
westerly, around to north and easterly. Relative humidities will
be generally low, especially in the warned area, around 10 to 25%
during the day.

Tuesday-Thursday:
Tuesday and onward, weak troughing will remain over NorCal,
maintaining near normal temperatures and periodically breezy
winds. Be sure to follow the forecast at weather.gov for any
updates!

&&

.AVIATION...
VFR conditions prevail at TAF sites across the forecast period.
Winds in most areas will remain at 12 kts or less for the forecast
period, except in the Delta and isolated Valley locations. West-
southwest winds in the Delta will gust 20 to 25 kts starting at
21z today, northern San Joaquin Valley and Sacramento sites seeing
occasional gusts up to 15 kts after 22z.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM Saturday to 11 AM PDT Monday for
Butte County Below 1000 ft-Central Colusa County Incl. I-5-
Central Glenn Co & Interstate 5-Eastern Colusa County-Eastern
Glenn County-Glenn/Colusa Coast Range Above 3000 ft-N. Sac
Valley in Tehama County-Shasta Metro-Sierra (Tehama-Plumas) 1000-
3000 ft-Sutter/Yuba counties below 1000 ft-W. Glenn/Colusa
Foothills 1000-3000 ft.

&&

$$