680
FXUS66 KSTO 252047
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
147 PM PDT Fri Sep 25 2026

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



.KEY MESSAGES...

   - Periods of breezy to gusty winds through early next week.

   - Periods of Elevated Fire Weather Conditions for portions of
     interior NorCal into early next week due to breezy winds and
     low humidities.

  - Areas of Moderate HeatRisk in the Northern San Joaquin Valley
    into this evening.

  - Slight chances (15-30%) for showers in the Sierra south of Hwy
    50 on Monday, along with low chances (around 10%) for
    isolated thunderstorms. Otherwise, primarily dry weather
    continues into next week.

 &&

.DISCUSSION...

...Today-Sunday (9/25-27)... Sunny skies are being observed
across Northern California this afternoon, with just some thin
cirrus clouds and some cumulus and lenticular clouds over the
mountains. Temperatures this afternoon are 5 to 10 degrees lower
than yesterday, with highs in the low to mid 80s across the
Valley, warmest in the northern San Joaquin Valley. Winds are
breezy, especially in the mountains, where gusts are 20-30+ mph.

Dry weather is expected through the weekend as a broad trough
moves inland, bringing periods of breezy onshore flow  through
the weekend, with temperatures continuing to trend cooler. By
Sunday, Valley highs will be in the 70s, about 10 degrees below
normal. On Saturday there will be breezy winds for the northern
and central Sacramento Valley and adjacent mountains and
foothills, with gusts in those areas up to 20 to 30 mph. The
combination of gusty winds and low afternoon humidity percents in
the upper teens to low 20s bring a several hours of elevated fire
weather conditions.

...Monday-Tuesday (9/28-9/29)... Periods of breezy northerly
flow are forecast to develop on Monday through the Sacramento
Valley as the trough closes off and tracks southward. There is
still some uncertainty over the track of the low. There is the
potential for showers over the Sierra south of Hwy 50, with a
20-30% chance of a tenth of an inch of rain in that area Monday.
Most of the forecast area is expected to remain dry with
downsloping northeasterly to easterly winds over the Sierra, and
breezy north winds through the Valley, continuing into Tuesday.
These will bring the potential for elevated fire weather
conditions. Temperatures trend warmer on Wednesday, with highs
reaching around 90 for Valley locations.

...Wednesday-Friday (9/30-10/02)... Temperatures remain above
normal as weak eastern Pacific ridging builds over interior
NorCal. Winds should generally remain light. No precipitation is
expected.

&&
.AVIATION...


VFR conditions continue through the rest of today and into
tonight, with mostly clear skies. Sustained winds will be
generally less than 12 kts. Breezier Delta winds are expected
tonight into Friday through 18Z.
&&

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

$$