544
FXUS66 KSTO 172203
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
203 PM PST Sat Jan 17 2026

.KEY MESSAGES...

 - Dry weather expected through much of next week with Valley
   fog/low clouds

 - Warm and dry weather prevails at higher elevations with
   offshore flow

 - High uncertainty for very light mountain showers late next
   week

&&

.DISCUSSION...

...Today Through Mid Next Week...
Current GOES-West visible satellite imagery illustrates the dense
fog from this morning lifting and burning off this afternoon. The
Dense Fog Advisory has expired as visibilities have improved
significantly across the area. 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 Sunday morning. The fog and low
clouds will delay some of the daytime heating in those lower
elevations beneath the fog. 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. This pattern will continue this weekend
through mid next week.

...Late Next Week...
Ensemble guidance and cluster analysis indicate the flattening of
the upper level ridge late next week, with the potential for a
weak system to bring very light precipitation, with a 25 to 50
percent chance of 0.01" across interior NorCal. Latest guidance
from WPC brings in just a few hundredths over a small area in the
mountains for QPF. 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 northern California in the 8 to 14 Day Outlook which
covers the January 25th through 31st timeframe.

&&

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

&&

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

&&

$$