646
FXUS66 KSTO 252007
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1207 PM PST Sun Jan 25 2026

.KEY MESSAGES...

 - Patchy fog in the Valley and lower foothills each morning

 - Slight chances for light showers mid week and again over the
   weekend mainly north of Interstate 80

&&

.DISCUSSION...

...Today through Monday...
Current GOES-West visible satellite imagery illustrates low
stratus across the Valley and lower foothills starting to
gradually break up, and a swath of mid to high level clouds
moving overhead across interior northern California on this Sunday
afternoon. The cloud cover is keeping temperatures quite a bit
cooler compared to 24 hours ago. The upper level pattern will
feature upper level ridging with an embedded shortwave. Dry
conditions will continue across the area the next couple days,
with daily chances for patchy morning fog in the Valley and lower
foothills. For tonight into Monday morning, high resolution
guidance indicates a 50 to 70 percent chance of visibilities less
than 1/2 mile in the northern San Joaquin Valley, and a 20 percent
chance from Sacramento northward. Be sure to slow down and use
low-beam headlights if fog is encountered while driving.

...Tuesday through the Weekend...
By Tuesday afternoon, chances for light showers return to the
area and continue into early Wednesday, mainly from Interstate 80
northward as an upper level trough deepens over the Eastern
Pacific Ocean. Upper level ridging then looks to build back in for
the late week timeframe with dry weather and morning fog.
Ensemble guidance then indicates the potential for another system
to approach the Pacific Northwest by the weekend with some
additional chances for light precipitation once again mainly north
of Interstate 80. Little to no impacts are expected from either
system as forecast precipitation amounts are fairly light.

&&

.AVIATION...
General VFR conditions for much of interior NorCal except for
patchy MVFR/IFR/LIFR conditions in fog and mist from 09Z-19Z
Monday and again after 09Z Tuesday in the Valley, with best
chances from Sacramento southward. Surface winds generally below
10 kts through the forecast period.

&&

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

&&

$$