585
FXUS66 KSTO 261754
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1054 AM PDT Fri Jun 26 2026

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


.KEY MESSAGES...

 - Isolated showers today with additional chances for isolated
   mountain showers/thunderstorms on Saturday.

 - Elevated fire weather conditions Sunday-Monday due to increased
   North winds across portions of the Valley.

 - Cooler temperatures and breezy onshore flow expected Tuesday
   onward.


&&

.DISCUSSION...

A trough from the Gulf of Alaska will move through the area
today-Saturday, bringing isolated light showers and mountain
thunderstorm chances. A few showers will move over the Valley
today, although the majority of precipitation will be over the
mountains. Forecast precipitation amounts are generally less than
0.10", however, amounts 0.20" to 0.40" are forecast over the
northern Sierra and southern Cascades. There is a 10% chance for
isolated thunderstorms along the Sierra crest today, but the
highest likelihood for any thunderstorms development will be on
Saturday where there is a 15 to 20% chance over the southern
Cascades and eastern Shasta County. Additionally, enhanced
onshore winds are expected through the Delta and Valley through
Saturday introducing cooler temperatures and higher humidities
throughout the area.

As the trough exits into the Great Basin area, north winds
increase on Sunday through the western portions of the Sacramento
Valley & Delta. This will result in renewed fire weather
conditions Sunday into Monday. Strongest winds are expected Sunday
morning. Since the strongest winds are forecast during the
morning hours, they will not coincide with the lowest relative
humidities. That being said, winds will still remain gusty through
the afternoon hours when relative humidities will be in the teens
to mid 20s. Monday sees significantly weaker winds and therefore
also lower fire weather concerns.

Latest deterministic EC and GFS depicts a lobe of energy phasing
out of the exiting trough on Sunday, which may introduce
additional mountain shower and thunderstorm chances north of
I-80. The overall environment will be dry which may negate any
shower development, however, the feature will be closely monitored
for any significant changes and/or additional fire weather
concerns.

Moving further into the week, another cooling trend is expected
Tuesday and beyond, resulting in below normal temperatures across
interior NorCal and periods of breezy onshore flow in the
forecast.

&&


.AVIATION...
General VFR conditions are expected over the next 24 hours. South
to southwest wind gusts 15-25 kts through 15Z Saturday in
Sacramento, and 20-35 kts through the forecast period for the
Delta and over the Sierra Crest. The remainder of the Sacramento
Valley will have gusts 15-25 kts through 06Z Saturday, with more
northerly wind gusts picking back up in the northern Sacramento
Valley around 23z Saturday. 10-15% chance isolated thunderstorms
in the Sierra/southern Cascades through 03z Saturday bringing
local MVFR/IFR conditions.


&&

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

$$