333
FXUS66 KSTO 012149
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
149 PM PST Sun Feb 1 2026

.KEY MESSAGES...

 - Dry weather with patchy fog in the Valley and lower foothills
   expected through the week, with almost 0% chance of
   precipitation tonight into Monday.

 - Temperatures gradually increase to above-normal throughout this
   this week.

 - Non-zero chances for precipitation next weekend, though timing
   and amounts are still highly uncertain.

&&

.DISCUSSION...

...Sunday through Monday... A weak trough will disrupt ridging
aloft this afternoon and evening. While there is still a non-zero
chance for precipitation in Shasta County this evening, most
likely high-res solutions show little to no rain reaching the
ground. Ridging builds back in on Monday, starting a gradual
warming trend across interior NorCal. North to east winds will be
breezy through the northern and central Sacramento Valley and the
Sierra mountains/foothills on Monday with gusts 15-25 mph at
times. These winds will work against widespread dense fog
development in the central Sacramento Valley, but isolated
coverage is still possible in the southern Sacramento Valley, with
more widespread dense fog likely in the northern San Joaquin
Valley tonight and Monday night.


...Tuesday through Saturday... Ridging continues to build across
the area through much of next week, bringing gradually warming
temperatures, along with continued chances for morning fog. Temperatures
will climb to above normal by mid-week, and strong inversions
will keep conditions warm and dry in the foothills through
midweek. Otherwise, breezy offshore flow is expected at times.

Ensemble guidance highlights another shortwave trough approaching
the region towards next weekend which is expected to bring cooler
temperatures and potential for unsettled weather. There is still a
high degree of uncertainty in the timing and amounts of any
precipitation however, so check back in as we get closer for
forecast updates.

&&

.AVIATION...
Lingering MVFR conditions this afternoon mainly in the northern
San Joaquin Valley from BR/HZ, elsewhere VFR conditions through
around 03z Monday. BR/FG to develop in the southern Sacramento
Valley, Delta, and northern San Joaquin Valley resulting in
IFR/LIFR conditions through around 20z Monday. Surface winds below
12 kts across the region through 18Z Monday. North to east winds
increase through the northern/central Sacramento Valley after 18Z
Monday with gusts 10 to 15 kts at times.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from 11 PM this evening to noon PST Monday
for Northern San Joaquin Valley-Southern Sacramento Valley.

&&

$$