772
FXUS66 KSTO 182041
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1241 PM PST Sun Jan 18 2026

.KEY MESSAGES...

 - Dry weather expected this week with Valley fog/low clouds

 - Warm and dry weather at higher elevations with offshore flow

 - High uncertainty for very light mountain showers next weekend

&&

.DISCUSSION...

...Today Through Friday...
Latest GOES-West visible satellite imagery shows the fog and low
clouds from this morning gradually lifting and burning off this
afternoon, with a few mid to high level clouds passing overhead.
The Dense Fog Advisory was allowed to expire at noon as a result
of improving visibilities across the Valley and Delta. The region
remains under upper level ridging, with dry and mild weather
prevailing for much of interior northern California. This
inversion pattern is bringing daily chances for fog and low clouds
in the Valley and lower foothills, especially from Marysville
southward. High resolution guidance shows a 50 to 70 percent
chance of visibilities less than 1/2 mile once again tonight into
Monday morning. The fog and low clouds will delay some of the
daytime heating in those lower elevations. Elsewhere, above
normal temperatures are forecast, along with periodically breezy
offshore flow. The warmer temperatures and offshore flow will keep
humidity fairly dry for higher terrain. Some minor modifications
were made to the temperature, fog and humidity to account for the
contrasts above and below the fog layer. This pattern will
continue through at least the middle of the week before the upper
level ridge starts to flatten and temperatures gradually start to
cool later in the week.

...Next Weekend...
Ensemble guidance and cluster analysis continue to indicate the
potential for a weak system to bring very light precipitation over
the weekend, with a 15 to 45 percent chance of 0.01" of rain
showers across interior NorCal, with the best chances over the
northern mountains and southern Cascades. A cooling trend in
temperatures is expected as well, with forecast highs in the 50s
to around 60 for the Valley. The Climate Prediction Center is then
indicating that above normal temperatures and above normal
precipitation chances are favored for much of northern California
in the 8 to 14 Day Outlook. This suggests the potential for a
somewhat unsettled weather pattern by the end of the month into
early February. There is quite a bit of uncertaity with details on
this so be sure to check back more for details as we get closer.

&&

.AVIATION...
Lingering IFR/LIFR conditions in central/southern Sacramento
Valley, Delta, and northern San Joaquin Valley through 22z Sunday,
potentially lingering until 00z Monday for some areas. FG/BR
expected to develop around 03z-06z Monday with similar aerial
extent. Surface winds below 12 kts in the lower elevations, with
local E-NE wind gusts of 15-25 kts in the Sierra and Southern
Cascades after 06z Monday.

&&

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

&&

$$