415
FXUS66 KSTO 151222
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
422 AM PST Thu Jan 15 2026


.KEY MESSAGES...

 - Dense fog this morning in the Valley and Delta

 - Dry weather expected next 7 days with a return to widespread
   Valley fog/low clouds and warm/dry weather at higher
   elevations.

&&

.UPDATE DISCUSSION...

A Dense Fog Advisory has been issued through 10 am this morning for
the Sacramento Valley, Delta and northern San Joaquin Valley due
to widespread fog developing, particularly near the Sacramento and
San Joaquin rivers and the Delta. Use caution driving, giving
yourself extra time for the morning commute. Use low beam
headlights and allow extra space between you and the vehicle in
front of you.

.PREVIOUS DISCUSSION...

...Today...

Dry and mild conditions once again continue across interior
NorCal, with any lingering patches of fog dissipating over the
next couple of hours. Patchy fog is likely to continue the next
several days, with a 50-70% chance of visibilities less than a
half-mile in the central and southern Sacramento Valley, and
northern San Joaquin Valley, on Thursday morning. Valley highs
continue around the low to mid 60s for the next week, with
slightly warmer temperatures in the foothills (into the upper
60s). Highest temperatures in the northern Sacramento Valley and
in the foothills.

...The Week Ahead...

A stationary ridge continues to amplify across the West Coast
into this week bringing potential for persistent low stratus and
fog to the Valley. Areas above the stratus (upper foothills and
mountains) will see above normal temperatures and dry conditions
with cooler temperatures below the clouds and fog, as long as the
stratus holds in place in the Valley. Low daytime humidity and
limited overnight recovery will be likely in higher elevation
areas as well. Similar chances today for breezy upper foothills
and mountain winds on Thursday with 50-80% chance of gusts 30 MPH
or greater. Gustier winds will be fairly limited by elevation,
with only light winds expected below ~2000 feet. If these winds
extend into the lower Valley elevations, it may be a limiting
factor for fog and stratus development but is not forecasted at
this time. Today and Thursday look to be the warmest days of the
week.

&&


.AVIATION...


IFR/LIFR conditions in FG this morning through 18Z, then expected
to see some potential for lingering MVFR/IFR cigs into the
afternoon as BR/FG dissipates. Breezy to gusty downslope winds
anticipated over the Sierra with gusts up to 20 to 25 kts.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM PST this morning for Carquinez
Strait and Delta-Central Sacramento Valley-Northern Sacramento
Valley-Northern San Joaquin Valley-Southern Sacramento Valley.

&&

$$