940
FXUS66 KSTO 091902
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1202 PM PDT Thu Jul 9 2026

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


.KEY MESSAGES...

 - Near to above-normal temperatures and areas of Moderate
   HeatRisk today-Monday, with continued onshore flow moderating
   overnight temperatures.

 - Breezy southerly winds and marginally low daytime humidity will
   bring elevated fire weather conditions on Friday.

 - Potential for monsoonal moisture to bring showers and
   thunderstorms to the Sierra early next week.

&&

.DISCUSSION...
Clear skies once again this early afternoon across interior
NorCal. Warmer temperatures are being observed compared to similar
times yesterday, as broad ridging has developed across portions of
SoCal with zonal heights aloft for NorCal. Triple-digit heat is
expected in the northern Sacramento Valley today, with Redding and
Red Bluff both forecast to hit 104 this afternoon. Rest of the
Valley looks to remain in the 90s. Seasonable high temperatures
continue through the weekend and into next week, with mostly Minor
HeatRisk and isolated Moderate HeatRisk. By Tuesday, widespread
Moderate HeatRisk will develop in the Valley.

Southerly wind gusts have slightly increased on Friday, with
marginally low daytime humidity in the forecast. That said,
elevated fire weather conditions will exist tomorrow afternoon and
evening for the Valley and foothills. South wind gusts of
25 to 30 mph will be possible, strongest in the northern
Sacramento Valley.

Latest forecast trends are keeping a potential push of monsoonal
moisture moving into the region by late Sunday night/early Monday
morning. High pressure is forecast to move into the Four Corners
region, while off-shore troughing develops in the eastern Pacific.
Monsoonal moisture will begin moving into the region by late
Sunday and introduce mountain thunderstorm chances. What remains
uncertain is just how much moisture there will be and how far west
will moisture will be. The EFI continues to show QPF Shift of
Tails over portions of the Sacramento Valley and northern San
Joaquin Valley and adjacent foothills/mountains and the EC shows
modest PWAT values nosing into the Valley Sunday night. We will
need to see if we will have any shortwave vorticity support from
the offshore trough to help instability develop aloft. Those
conditions could lead to some elevated thunderstorm potential in
lower elevations, but confidence remains low on Valley/foothill
t-storms developing at this time. Best chances for thunderstorms
remain in the Sierra mainly south of I-80 beginning Monday
afternoon continuing through at least Wednesday. We will continue
to monitor the trends and hope to have better details as we move
into the weekend.

&&

.AVIATION...

VFR conditions prevail across interior NorCal next 24 hours.
Surface winds from south to southwest around 15 kts with
occasional gusts up to 20 kts in Sacramento Valley. Surface winds
around 15 kts in northern San Joaquin Valley beginning around 22z
today as onshore flow builds.
&&

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

$$