367
FXUS66 KSTO 262012
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
112 PM PDT Fri Sep 26 2025

For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.


.SYNOPSIS...

Hot, dry, and breezy conditions across the northern Sacramento
Valley resulting in critical fire weather conditions today and
into Saturday morning. Widespread wetting rain early to mid next
week across the forecast area, with the highest chances within the
Coastal Range and southern Cascades. Cooler temperatures are also
expected next week.

&&

.KEY MESSAGES...

*  TODAY THROUGH SUNDAY:

 - Red Flag Warning continues for the northern Sacramento Valley
   through 5am Saturday as conditions remain hot, dry, and breezy
   resulting in critical fire weather conditions.

 - Lingering moisture and forcing from an upper level low brings
   the chance for isolated showers and storms along the Sierra
   Crest south of Highway 50 Saturday and Interstate 80 on Sunday.

* MONDAY THROUGH THURSDAY:

 - Confidence continues to increase for a trough to deepen over
   the eastern Pacific Monday through Wednesday, with increasing
   moisture and forcing across northern California. Nearly all the
   ensembles are in agreement on this occurrence and a widespread
   wetting rain potential across northern CA starting late Sunday
   and continuing through Wednesday.

 - Showers overspread the Coastal Range late Sunday night and push
   into the Sacramento Valley and San Joaquin Valley Monday
   morning. Periods of moderate rainfall are possible as the
   system tracks across the area. 60-90 percent chance in seeing
   over a quarter of an inch (Monday through Wednesday) within the
   Sacramento Valley and 40-60 percent chance within the San
   Joaquin Valley. Probabilities in seeing over an inch of QPF are
   60-80 percent within the Coastal Range and southern Cascades
   Monday through Wednesday. Lower probabilities within the
   Sacramento Valley and San Joaquin Valley for over an inch
   (10-30 percent).

 - Lingering synoptic level forcing and moisture from the system
   may bring additional shower and isolated thunderstorm chances
   within the mountains end of the work week.

.AVIATION...

VFR conditions prevail through the TAF period, with breezy
northerly winds around RDD and RBL through 01-03z. Gusts reach up
to 25kts in these areas. Otherwise, light winds for the remaining
TAF sites. SKC to FEW for sky coverage through the TAF period.
Winds go light and variable overnight through the end of the TAF
period.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 5 AM PDT Saturday for Northern Sacramento
Valley to Southern Tehama County Line Below 1000 Ft.

&&

$$