480
FXUS66 KSTO 052117
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
117 PM PST Fri Dec 5 2025

.KEY MESSAGES...

 - Periods of clouds, mist, or fog continue in the Central Valley
   for the next few mornings

-  Seasonable temperatures and light winds are forecast over the
   next several days

-  Tonight - Early Sat. AM`s rain chances for Shasta County have
   lowered with only a 10-30% of measurable rain.

&&

.DISCUSSION...

...Today...
Current GOES-West visible satellite imagery illustrates the
blanket of stratus in the Central Valley gradually eroding, with
some high clouds passing overhead from the north. Visibilities
have improved across the Central Valley this afternoon, but still
see swaths of low clouds/stratus clouds over the Valley. We can
expect another round of patchy dense fog and low clouds once again
tonight into Saturday morning with best chances from Marysville
southward again. Dry weather and seasonable temperatures are
forecasted for the region, with 50s to 60s in the Valley and
foothills, and 40s to 60s in the mountains for the daytime highs.
Highs are trending several degrees cooler than initially
forecasted due to the persistence of the fog/low clouds, keeping
max temperatures from being fully actualized.

...Tonight-Sunday...
A weak system passing to the north over the weekend may bring
some isolated, light showers to the Shasta County mountains,
however little to no impacts or accumulations are expected.
Elsewhere, dry conditions will persist over the weekend with daily
chances for fog, mist and low clouds especially in the Valley.
High temperatures are forecast to be in the 40s to 60s across
interior NorCal.

...Next Week...
High pressure builds across the region next week, allowing for a
gradual warming trend with high temperatures warming to the 50s
to near 70 (mainly for areas outside of stratus/fog
development). Dry conditions will continue through next week.
Some ensembles are indicating a pattern change in mid December but
there is a large amount of uncertainty as it is too far out in
time.

&&

.AVIATION...

Lingering low cigs and mist across the Central Valley this
afternoon and evening, although some sites may briefly return to
VFR conditions. Another round of BF/FG and low stratus returns
tonight after 03Z-12Z Saturday, with areas of MVFR/IFR
conditions, locally IFR, particularly from Sacramento southward.
Light and variable surface winds less than 12kts.
&&

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

$$