216
FXUS66 KSTO 231930
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
1230 PM PDT Wed Sep 23 2026
.KEY MESSAGES...
- Periods of Elevated Fire Weather Conditions for portions of
interior NorCal on Thursday and again Friday PM-Saturday AM
due to breezy winds and low humidities.
- Areas of Moderate HeatRisk in the Northern San Joaquin Valley
on Thursday.
- Low chances for isolated showers around Shasta county Thursday
night into Friday. Otherwise, primarily dry weather continues
into next week.
- Periods of breezy to gusty winds Friday through early next
week.
&&
.DISCUSSION...
...Today-Thursday (9/23-9/24)...
Clear skies are being observed across Northern California this
afternoon, with high temperatures forecast to reach the upper 80s
to low 90s across the Valley. These warm temperatures are on
track to peak Thursday, with Valley highs in the low to mid 90s
and areas of Moderate HeatRisk across portions of Stanislaus
County. Winds will be light overall today, with increased onshore
flow expected Thursday as a trough passes through the Pacific
Northwest. West to south winds will be gusty at times through the
Valley with gusts 20 to 35 mph. This, in conjunction with lower
daytime humidities in the low 20s to upper teens, will bring a
period of Elevated Fire Weather conditions to the northeastern
Sierra foothills during the day on Thursday.
Additionally, there is a low, nonzero chance (less than 20%) of
isolated showers along the northwestern edges of Shasta County
late Thursday night into Friday. However, any precipitation is
expected to remain further west.
...Friday-Sunday (9/25-9/27)...
The aforementioned system will bring additional periods of breezy
to gusty winds Friday into Saturday, with winds out of the west-
southwest on Friday, then shifting out of the north on Saturday.
Strongest gusts are expected over the mountains and in the
northern Sacramento Valley with gusts 20 to 30 mph. As a result,
additional Elevated Fire Weather conditions are expected in the
northern Sacramento Valley Friday night into Saturday due to the
combination of gusty winds and low humidities in the 20s to low
30s.
Additional periods of breezy to gusty southerly flow is expected
on Sunday as a trough deepens and pushes through Northern
California. Models have been going back and forth regarding any
moisture associated with this feature, but are currently favoring
a continued dry pattern.
...Monday-Wednesday (9/28-9/30)...
Periods of breezy northerly flow is forecast to develop on Monday
through the Sacramento Valley as the aforementioned trough tracks
over the Desert Southwest. Lingering breezy north winds through
the Valley and downsloping winds in the Sierra are favored on
Tuesday as well. Temperatures are then on track to trend warmer
Monday onward as weak ridging builds and heights rise over
interior NorCal.
&&
.AVIATION...
VFR conditions continue through the rest of today and into
tonight, with mostly clear skies. Winds in the Delta will be
lighter today compared to yesterday, with west-southwest gusts to
10 kts. Winds in the Valley will be generally less than 12 kts.
Breezier onshore winds are expected on Thursday afternoon and
Friday.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
