Rio Oso, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

451
FXUS66 KSTO 102126
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
226 PM PDT Sun Aug 10 2025

.DISCUSSION...

.SYNOPSIS...
Widespread Moderate HeatRisk and local Major HeatRisk in the
foothills continues into Monday with triple digit highs in the
Valley. Temperatures cool to more seasonable levels Tuesday, slightly
below normal by midweek and then continue to trend lower into the
weekend. Dry weather continues.

&&

.KEY MESSAGES...

*Today:
 - Well above normal temperatures continue as upper level ridging
   remains over the region
Temperatures remain hot on Monday with
   widespread Moderate HeatRisk and local Major HeatRisk across
   the Valley and foothills and into the mountains
 - Probability of high temperatures > 100F:
   --Northern Sacramento Valley: 80-100%
   --Remainder of the Valley: 35-75%
 - A weak Delta breeze will bring slightly cooler low temperatures
   tonight into Monday morning to influenced areas, with elevated
   Minimum temperatures continuing elsewhere, especially in the
   foothills and northern Sacramento Valley.
 - Probability of high temperatures > 100F:
   --Northern Sacramento Valley: 90-100%
   --Remainder of the Valley: 40-90%

*Tuesday-Wednesday:
 - The East Pacific ridge axis aloft shifts westward by Tuesday as
   an upper trough from western Canada drops down. This will
   bring increased onshore flow and cooler temperatures, but lacks
   moisture, with dry weather continuing
 - The increased Delta breeze will give some relief with for the
   Delta and southern Sacramento Valley, especially by Wednesday
   morning
 - Seasonable high temperatures return for Tuesday, near to
   slightly below normal highs by Wednesday

*Thursday to Late This Week:
 - Temperatures continue to trend lower mid to later week,
   slightly below average Thursday and continuing to trend lower
   into the weekend
 - Periodically breezy onshore flow continues through the week
   into next weekend
 - Dry weather continues

.Changes from previous forecast...
- Little change.

&&

.AVIATION...
VFR conditions expected to prevail next 24 hours across interior
northern California. Sustained surface winds generally 12 kts or
less at TAF sites. West-southwest wind gusts 15-25 kts through the
Delta 00z-12z Monday.

&&

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

$$