423
FXUS66 KSTO 292055
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1255 PM PST Mon Dec 29 2025

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


.KEY MESSAGES...

 - Dry weather through mid-week with cold overnight lows and areas
   of frost and fog/mist/low clouds in the  Valley

 - Next weather system moves in New Year`s Day bringing the
   potential for showers and mountain snow showers into the
   weekend, although confidence is low on details at the moment

&&

.DISCUSSION...

...Today through Wednesday...
Fog and low clouds returned this morning across portions of the
central Valley. Lower visibilities are currently being observed
from Marysville AP through Stockton AP with visibilities at or
below 0.25 miles. With the current upper level ridging support and
the recent rain, we will keep low clouds/fog/misty conditions in
the Valley the next few days. Resultant high temperatures will
likely be cooler than forecast, so some adjustments to Valley high
temperatures have been made for the afternoon forecast package.

Some morning frost will again be possible, mainly in areas that
are not seeing low cloud decks or fog. Currently, Redding, Red
Bluff, and areas west of I-5 will stand the best chances, as clear
skies are dominating at the time of this writing.

...New Years Day through Sunday...
Ensembles are continue to depict another round of active weather
entering the region by New Years Day and continuing through the
weekend and into next week. Latest forecast runs have shown a
slight increase in rain totals, with minor fluctuations in snow
totals. Initial onset of precipitation looks to be Wednesday
afternoon/evening, with mostly if not all rain as snow levels look
to be above 8500 feet. Snow levels look to crash late Friday night
into Saturday, with levels dropping to around 6000-7000 feet.
Uncertainty remains in exact precipitation totals, how fast snow
levels fall, and if the Valley gets shadowed as heights are again
suggesting a west to east orientation. Regardless, holiday travel
looks to be impacted once again for New Years Day and into early
next week. We are considering a Winter Storm Watch possibly
beginning Friday evening, and will likely make a decision sometime
tomorrow on issuance. Stay tuned to the forecast and check our
impacts briefing (link at the top of this discussion) for latest
thinking and potential impacts for the New Years weather system.

&&

.AVIATION...

IFR/LIFR ceilings and/or visibilities are likely to impact the
Sacramento area terminals, as well as Stockton and Modesto through
much of the 24 hour TAF period as a result of fog/stratus. Limited
opportunity for improved visibilities may occur in the
afternoon/evening hours, but are then expected to deteriorate
again overnight. The BKN/OVC cloud deck will be difficult to mix
out today as satellite trends depict an overall expansion over
the course of Monday morning. Winds are forecast to be less than
12 kts at terminals today.

&&

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

$$