944
FXUS66 KSTO 171945
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1245 PM PDT Wed Jun 17 2026

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


.KEY MESSAGES...

 - Hot and dry conditions today, followed by a cool down through
   the early part of the weekend.

 - Chances for mountain showers/thunderstorms along the Sierra
   today (south of Highway 50), Thursday, and Friday.

&&

.DISCUSSION...

Hot and dry conditions continue today, with highs in the 90s
across the Valley and around 100 degrees in the northern
Sacramento Valley. Moderate HeatRisk for today across the Valley
and adjacent foothills. Delta flow will help bring temperatures
down this evening and into the overnight, with west to
southwesterly winds at 10-20kts. There is an isolated chance for a
shower or thunderstorm in the Sierra (along the crest) along and
south of Highway 50 this afternoon and evening. CAMS have hinted
at these quick moving isolated showers and storms, with frequent
lightning and gusty outflows possible.

The ridge aloft starts to break down and shift east tomorrow
through the weekend helping bring temperatures down across the
area. Highs will generally be in the 80s across the Valley, with
the warmest temperatures in the northern Sacramento Valley.
Troughing sets into the region Thursday and Friday, with increased
moisture content and instability. This brings the chance for
isolated showers and thunderstorms to the mountains both days.
Some of these storms could have frequent lightning, gusty
outflows, quick downpours, and the potential for new fire starts
where lightning happens outside of the rain. Best chances for
showers and storms would be during the afternoon and early evening
hours on both days. The higher instability, moisture, and coverage
lies on Friday afternoon. Some of these storms may be isolated dry
thunderstorms on Thursday. Elevated fire weather conditions are
anticipated due to the potential for elevated mountain
thunderstorms and gusty thunderstorm outflow winds Thursday and
Friday.

Temperatures will be at or below normal on Saturday, but start to
increase as we transition back to ridging Sunday and into next
week. Confidence is increasing that we return to 90s and lower
100s early next week, with low RH values and potential for breezy
conditions.

&&

.AVIATION...

VFR conditions are expected over the next 24 hours. Winds will
begin to increase later this afternoon and evening in the Delta,
with westerly gusts up to 20kts possible for the Sacramento
sites. Winds will be out of the NW to WNW for MOD and SCK this
evening and out of the south for RBL and RDD. Later in the night,
winds will go light and variable through 18z tomorrow.

&&

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

&&

$$