135
FXUS66 KSTO 292048
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
148 PM PDT Fri Aug 29 2025

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


.DISCUSSION...

.SYNOPSIS...
Temperatures trend above average for the weekend into next week,
with some areas of Moderate HeatRisk developing. Dry weather is
expected except a slight chance of afternoon showers and
thunderstorms along the Sierra crest south of US Highway 50
Tuesday through Friday.

&&

.KEY MESSAGES...

* Today:

 - High temperatures will be seasonable, with mostly mid 90s in
   the Valley; cooler mid to upper 80s to low 90s in the Delta.
   Minor HeatRisk across interior NorCal.
 - PacNW low builds off coast; enhancing onshore flow and ushers
   in a slight (10%<) chance of an afternoon and evening
   shower/t-storm in the far eastern corner of Tuolumne County,
   dry conditions elsewhere

 Saturday - Friday
 - High temperatures through Thursday mainly in the low triple
   digits across the Valley, upper 90s in the Delta and foothills
 - Warmest temperatures are expected on Tuesday and Wednesday,
   with widespread triple digit highs, along with widespread
   Moderate HeatRisk and local areas of Major HeatRisk
 - Minor drying brings lower relative humidity, especially to the
   northern Sacramento Valley and adjacent higher terrain, where
   daytime RHs in the mid-teens are forecast
 - a slight (15-20%) chance of afternoon showers/thunderstorms for
   the Sierra crest from US Highway 50 southward Tuesday through
   Friday
 - Cooler, more seasonable temperatures expected for the end of
   the week

.Changes from previous forecast...
- Thunderstorm potential for the weekend into Monday has
  diminished.

&&

.AVIATION...
VFR conditions and clear skies are expected over the next 24
hours. Winds will be generally 10kt or less. Cumulus build-ups
will be possible over the Sierra crest this afternoon.

&&

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

$$