188
FXUS66 KSTO 021926
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1226 PM PDT Sat May 2 2026

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


.KEY MESSAGES...

 - Chance for scattered thunderstorms this evening and again on
   Sunday afternoon/evening for areas around Shasta county and
   into the higher elevations. Little to no precipitation chances
   for the Valley.

 - Shower and thunderstorm chances early next week for the Valley,
   mountains, and foothills along with warming temperatures by the
   end of next week.

&&

.DISCUSSION...

...This weekend...

Main upper level system moves across CA and the southwestern
United States this weekend and into early next week. Cooler
temperatures are expected along with higher elevation
thunderstorm chances, with little to no precipitation within the
Valley.

Chances for scattered thunderstorms increase this evening across
areas in Shasta county through the higher elevations. Current
HIRES guidance has storms developing along the Coastal Range and
Sierra around 21-23z and continuing through 04z. Some of the
storms could be on the stronger side with frequent lightning and
the potential for some small hail. However, looking at soundings
across the area, instability is lacking and shear profiles are
weak. None the less, the chances are still there for scattered
thunderstorms developing this evening.

As we move into Sunday afternoon and evening, instability
increases across the area as the main upper level system moves
through the region. HIRES guidance has an area of thunderstorms
developing along the Sierra and moving through Shasta county and
the Coastal Range. Shear profiles indicate the potential for a few
stronger storms to develop as they move through the area. This
will be dependent on cloud coverage and how fast the surface can
heat up for instability to increase. The chance is there for a few
stronger storms to bring frequent lightning, hail, gusty winds,
and brief moderate to heavy rain rates. If you have plans this
weekend have a way to receive alerts especially traveling within
the higher elevations.

...Next Week...

Chances for showers and thunderstorms Monday afternoon and
evening for the Valley, mountains, and foothills. A few locations
at the higher peaks will see brief snow showers, with minor
accumulations. There will be continued chances for showers and
storms Tuesday, with drying conditions by Wednesday.

By the end of next week, a high pressure system will begin to
intensify across the western United States. As this happens we dry
out faster and temperatures warm quickly. Minor HeatRisk for the
Valley Wednesday, with more widespread Minor HeatRisk Thursday and
Friday. Indications are there for the heat to increase by next
weekend and into the following week, with probabilities of seeing
over 90 degrees sitting around 60 percent for the Valley.

&&

.AVIATION...

VFR conditions prevail through the TAF period. Winds remain
around 5-12kts for the sites, with occasional gusts up to 20kts
for the Sacramento sites. Chances for rain remain over the
mountains this evening and overnight, with a low chance near RDD.
Winds go light and variable overnight, with BKN clouds.

&&

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

&&

$$