435
FXUS66 KSTO 272127
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
127 PM PST Tue Jan 27 2026

.KEY MESSAGES...

 - A quick-moving system will bring light rain and snow showers
   later this afternoon through early Wednesday morning, mainly
   from HWY 50 northward. Little to no impacts expected.

 - Dry weather with patchy fog in the Valley and lower foothills
   late week into the weekend.

 - Slight chances for very light showers over the Coast Range and
   Shasta County mountains on Sunday, with little to no impacts.

&&

.DISCUSSION...

...Today through Wednesday Morning...
Chances for light rain and snow showers return to the area later
this afternoon and continue into early Wednesday morning, mainly
from Highway 50 northward as a weak trough moves across the
region. Forecast precipitation amounts are expected to remain
light, with little to no impacts. WPC precipitation guidance
indicates amounts ranging from less than 0.1 to around 0.40 inches
in the Delta and the Sacramento Valley, with 0.10 to 0.50 inches
over the mountains (locally higher amounts up to 0.75"+). High
elevation snow showers are also expected above 5500-6000 feet,
with amounts generally ranging from less than 1 inch to around 3
inches, except for locally higher amounts near Lassen Park. Use
caution while driving as roads might be slick.

For tonight into Wednesday morning, high resolution ensemble
guidance indicates a 25 to 50 percent chance of visibilities less
than 1/2 mile across portions of the central/southern Sacramento
Valley and the northern San Joaquin Valley. However, cloud cover
may limit dense fog development.

...Wednesday Afternoon through the Weekend...
Upper level ridging builds back in behind the departing system,
with dry weather prevailing across the area late week into the
weekend. Morning fog potential also returns to the Valley and
lower foothills during this timeframe. Be sure to slow down and
use low- beam headlights if fog is encountered while driving.
Ensemble guidance then indicates the potential for another weak
system to approach the Pacific Northwest by the weekend with some
additional chances for very light precipitation over the mountains
north of Interstate 80 by Sunday. Little to no impacts are
expected.

&&

.AVIATION...
General VFR conditions for much of interior NorCal except for
patchy MVFR/IFR conditions in fog and mist in the northern San
Joaquin Valley from 06Z-18Z Wednesday. Valley surface winds mostly
below 10 kts through the forecast period, with portions of the
central Sacramento Valley seeing gusts up to 20 kts. Foothill and
mountain gusts up to 25 kts through 09z Wednesday.

&&

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

$$