667
FXUS66 KSTO 092144
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
144 PM PST Sun Nov 9 2025

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

.KEY MESSAGES...

 - Dry and mild weather continues into the early week ahead.
 - An atmospheric river storm system mid to late week will bring
   widespread precipitation, gusty winds, cooler temperatures,
   and mountain snow.

.DISCUSSION...

...Today through Tuesday...

Dry and mild weather will continue through the remainder of today
through Tuesday, with temperatures above normal. High
temperatures will range from the upper 60s to lower 70s in the
mountains to the upper 70s within the Valley. Lowest RH values
will be in the Sierra along and south of I-80 through Tuesday.
HREF and HRRR continue to show patchy dense fog developing Monday
morning before sunrise and lasting through the late morning.
Confidence remains low on exact location and how dense the fog
becomes. Right now, best chances are in the southern Sacramento
Valley and the northern San Joaquin Valley Monday morning.

...Wednesday and Onward...

Ensembles are in good agreement on the ridge over western CONUS
broadening out and shifting eastward mid to late week, with a
deepening trough in the eastern Pacific. Abundant moisture flow
into the southwestern United States and synoptic forcing will aid
in the development of widespread rain and mountain snow. Breezy
winds and cooler temperatures will accompany this system
Wednesday through the end of the work week. Best chances for
thunderstorms will be on Thursday before the system moves further
inland by Friday. Mountain snow chances will be 8500 feet and
higher Thursday, but decrease as we move into Friday toward
5500-6000 feet and above. Thunderstorm chances shift toward rain
showers on Friday as the instability shifts with the system
eastward. Looking ahead to next weekend and beyond, guidance has
hinted at our active pattern continuing with the potential for
another system. Details remain highly uncertain at this time.

.AVIATION...

VFR conditions prevail through the rest of today and into
tonight. Light and variable winds through the period, with the
potential for patchy dense fog 10z through 17z within the
Sacramento area into Stockton. Confidence remains low on the
patchy dense fog and its exact location and timing. Otherwise, a
FEW to SCT clouds will move through the northern Sacramento Valley
this afternoon and evening, with FEW sky coverage tomorrow.
&&

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

$$