537
FXUS66 KSTO 282012
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
1212 PM PST Sun Dec 28 2025
.KEY MESSAGES...
- Dry weather through mid-week with cold overnight lows and
areas of frost and fog/mist/low clouds in the Central 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...
Current GOES-West visible satellite imagery illustrates that the
fog and stratus have lifted and are dissipating slowly this
afternoon, with clear skies elsewhere. The upper level pattern
will feature a ridge of high pressure over much of the region over
the next few days, allowing for dry weather to prevail. Locally
breezy offshore winds are expected in the typical N-E wind prone
areas including the Sacramento Valley west of I-5, Delta, and
mountain and foothill gaps and canyons. Strongest winds are
expected in the evening through early morning hours with gusts to
15-20 mph in the Valley and 20-30 mph over higher terrain. The
dense fog from this morning has lifted, and there is potential for
another round of dense fog each overnight through morning periods
through Wednesday. Be sure to give yourself extra time to reach
your destination each morning, and slow down and use low- beams if
you encounter fog!
In addition, cold overnight temperatures will bring concern for
sensitive vegetation in areas of frost tonight into Monday. A
Frost Advisory has been issued from 1 AM through 9 AM Monday for
elevations below 2,000 feet in the Motherlode, central/southern
Sacramento Valley, Delta, and northern San Joaquin Valley. Low
temperatures of 33 to 36 degrees will result in frost formation.
Frost formation may be inhibited by northerly flow along and west
of Interstate 5, or in areas where fog forms early on in the
night.
...New Years Day through Saturday...
While there is still quite a bit of uncertainty with the system
late this week due to a decent spread in possible solutions, the
latest forecast amounts from WPC/NBM have trended much wetter. The
latest probabilities from the NBM depict a 40-60% chance of 12
inches of snow above pass level in the mountains late this week
into the weekend. Probabilities have also increased for 1 inch of
rain, with a 25-50% chance in the Valley and 45-65% chance in the
foothills. Be sure to check back for details on this next system
as we get closer, and view the latest forecast at weather.gov.
&&
.AVIATION...
Lingering IFR ceilings and visibilities associated with fog
expected through late morning or early afternoon, particularly for
the Sacramento Area terminals. Otherwise, VFR conditions are
forecast to prevail through about 06Z Monday. Winds generally less
than 12 kts, with the exception of the northern Sacramento Valley
around KRDD and KRBL where periodic north gusts around 20 kt are
forecast through the day. Possible return of MVFR/IFR ceilings and
visibilities for the southern Sacramento Valley and northern San
Joaquin Valley terminals after 09Z Monday with redevelopment of
fog.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 1 AM to 9 AM PST Monday for Carquinez Strait
and Delta-Central Sacramento Valley-Motherlode-Northern San
Joaquin Valley-Southern Sacramento Valley.
&&
$$
