Alta Sierra, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

586
FXUS66 KSTO 261933
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1233 PM PDT Thu Jun 26 2025

.DISCUSSION...

.SYNOPSIS...
Seasonably warm temperatures accompanied by dry weather and
periodically breezy onshore winds through the remainder of the
week. A warming trend to widespread Moderate HeatRisk is then
anticipated over the the weekend into next week. Mountain
thunderstorm chances return early early to mid next week.

&&

.KEY MESSAGES...

* Through Friday:
 -Near to slightly above normal temperatures expected, with Delta,
  Valley, and foothills high temperatures in the 80s to 90s and
  70s to 80s in the mountains
 -Minor HeatRisk expected today with areas of Moderate HeatRisk
  on Friday

* 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%
 -Less than 10% probability of a shower or thunderstorm over the
  mountains this weekend

* 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

.Changes from previous forecast...
 -Decrease in mountain thunderstorm potential this weekend

&&

.AVIATION...
VFR conditions prevail across interior NorCal next 24 hours.
Surface winds generally below 15 knots, with an occasional gust up
to 20 knots in the Delta and in the mountains, as onshore flow
strengthens this evening in the Delta and drainage wind speeds
increase in the mountains.

&&

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

&&

$$