Grass Valley, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

889
FXUS66 KSTO 272013
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
113 PM PDT Fri Jun 27 2025

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

.DISCUSSION...

.SYNOPSIS...
Generally dry weather continues into next week with periodically
breezy onshore winds. A warming trend to widespread Moderate
HeatRisk is then anticipated over the weekend into the middle of
next week. Mountain thunderstorm chances return early to mid next
week.

&&

.KEY MESSAGES...

* Today:

 -Slightly above normal temperatures expected, with Delta, Valley,
  and foothills high temperatures in the 80s to 90s and 70s to 80s
  in the mountains. Triple digits possible in the northern
  Sacramento Valley.
 -Areas of Moderate HeatRisk in the Valley and Delta.

* This Weekend:
 -Warming trend into the weekend with high temperatures across the
  Delta, Valley, and foothills in the 90s to lower triple digits
  and 80s to low 90s expected at higher elevations
 -Widespread Moderate HeatRisk returns to interior NorCal for
  Saturday and Sunday
 -Probability of Valley high temperatures > 100F:
  Northern/Portions of the Central Sacramento Valley: 65-95%;
  Delta, S. Sac Valley, N. San Joaquin Valley: 10-30%

* Early to Mid Next Week:
 -Above normal temperatures persist into next week with Moderate
  HeatRisk, although increased onshore flow brings some relief to
  the Delta vicinity Monday-Tuesday
 -Slight (10-20%) probability of thunderstorms early to mid next
  week during the afternoon and early evening hours across the
  mountains of interior NorCal. Highest thunderstorm probabilities
  on Tuesday-Wednesday.

* Late Next Week:
 -Slight cooling trend with Minor HeatRisk returning to interior
  NorCal
 -Potential for mountain thunderstorm chances (5-15%) persisting
  through late week.

.Changes from previous forecast...
 -No changes from the previous forecast

&&

.AVIATION...
VFR conditions prevail across interior NorCal next 24 hours.
Surface winds below 15 knots, except in the Delta and vicinity,
northern Sacramento Valley, and in the mountains where surface
gusts up to 20 knots possible from 00z - 10z Saturday. &&

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

$$