222
FXUS66 KSTO 111923
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
1223 PM PDT Thu Jun 11 2026
.KEY MESSAGES...
-Critical fire weather conditions in the Sacramento Valley
through 5 PM PDT this evening due to gusty north winds and low
humidity.
-Well above normal temps in the lower elevations with widespread
Moderate HeatRisk / Areas of Major HeatRisk into the weekend &
triple-digit highs Thursday-Saturday.
-Significant warm-up Monday-Tuesday for the northern and central
Sacramento Valley, with increasing Areas of Major HeatRisk
&&
.DISCUSSION...
It`s sunny with well above normal temperatures this early
afternoon, 2-5 degrees warmer than yesterday. North winds mainly
peaked this morning, with gusts to 30 to 40 mph in the Sacramento
Valley, strongest along and west of Interstate 5. Humidity levels
barely recovered overnight, so far (around noon) have dropped into
the range around 10 to 20 percent, likely drying further by late
afternoon down into the single digits in some locations. The
winds have combined with the low humidity to bring extended
periods of critical fire weather conditions for the Northern
Sacramento Valley and into the foothills of the northern Coast
Range, with a Red Flag Warning remaining in effect through 5 PM
this evening. Winds will remain breezy through the afternoon but
should continue to decrease, becoming much lighter by evening.
Even after the Red Flag event is over, expect low humidity levels
and periods of breezy onshore winds into next week, bringing
elevated fire weather conditions into early next week. Onshore
flow, increasing humidity and cooling temperatures are expected
mid to late week, lessening fire weather concerns.
Triple digit Valley highs are expected this afternoon and
continue through at least the early weekend in many locations.
Widespread Moderate HeatRisk is expected starting this afternoon,
with areas of Major HeatRisk on Friday, and less so on Saturday
across mainly the foothills. Delta breeze influenced locations
will see some cooling through the weekend, while the northern
Sacramento Valley, mountains, and foothills are forecast to see
just slightly lower highs. The Heat Advisory continues for the
northern and central Sacramento Valley and adjacent foothills
through 11pm Saturday, June 13. While other areas in the Valley
will benefit from the Delta breeze cooling influence, especially
in the evening, it remains important for everyone in interior
NorCal to practice heat safety! Stay cool and hydrated, and
consider checking in on those more sensitive to heat.
Early next week high temperatures have trended higher for the
northern and central Sacramento Valley, and could see even higher
temperatures than for late this week. Major HeatRisk areas have
also been trending larger there. Temperatures are forecast to
trend lower mid to late week.
Mainly dry weather is expected into next week, but can`t
completely rule out a few stray showers or an isolated
thunderstorm over the Sierra crest south of US HWY 50 over the
weekend into Monday. Weak troughing and instability should at
least produce some afternoon cumulus buildups in that area.
&&
.AVIATION...
VFR conditions with clear skies over the next 24 hours. North
winds linger through the northern/central Sacramento Valley today
with sustained winds 10 to 20 kts and gusts 20 to 30 kts until
around 00z Friday. After 00z, winds shift to the west-northwest
across the southern Sacramento Valley and northern San Joaquin
with gusts up to 15 to 20 kts until 09z Friday and will linger
after 12z for the Delta. North winds 5 to 10 kts remain over the
northern Sacramento Valley into 18z Friday.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 11 PM PDT Saturday for Butte County Below
1000 ft-Central Colusa County Incl. I-5-Central Glenn Co &
Interstate 5-Eastern Colusa County-Eastern Glenn County-N. Sac
Valley in Tehama County-Shasta Metro-Sierra (Tehama-Plumas) 1000-
3000 ft-Sutter/Yuba counties below 1000 ft-W Tehama Co Foothills
1000-3000 ft-W. Glenn/Colusa Foothills 1000-3000 ft-W. Shasta
County 1000-3000 ft.
Red Flag Warning until 5 PM PDT this afternoon for Butte County
Below 1000 ft-C. Yolo/NE Solano including Woodland-Central
Colusa County Incl. I-5-Central Glenn Co & Interstate 5-Eastern
Colusa County-Eastern Glenn County-N. Sac Valley in Tehama
County-Shasta Metro-Sutter/Yuba counties below 1000 ft-W.
Glenn/Colusa Foothills 1000-3000 ft-W. Yolo County including
Capay/I-505-Yolo / Solano County Hills.
&&
$$