868
FXUS66 KSTO 311907
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1207 PM PDT Fri Jul 31 2026

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


.KEY MESSAGES...

 - Elevated Fire Weather Conditions in the northern Sacramento
   Valley and surrounding terrain, Burney Basin, and Sierra
   Foothills through Monday due to hot temperatures, low
   humidities, and breezy winds.

 - Widespread Moderate HeatRisk today into next week across the
   Valley and Foothills. Hottest temperatures expected Saturday-
   Monday.

&&

.DISCUSSION...

Today-Monday...

Latest GOES-West water vapor imagery depicts ridging beginning to
build into interior NorCal early this afternoon as troughing digs
offshore of the Pac NW. Little forecast change is anticipated as
the ridge axis centers over the Great Basin/Desert Southwest while
the offshore trough tracks onshore. Resultant high temperatures
today are expected to trend above normal today with widespread
triple digit high temperatures and more limited overnight cooling
then anticipated Saturday-Monday. Current probabilities for high
temperatures greater than 100F sit around 60-90% for the Delta,
Valley, and lower foothills. Additionally, 50-80% probabilities of
high temperatures greater than 105F are forecast for the northern
Sacramento Valley. As a result, moderate HeatRisk is expected
prevail area wide.

As the aforementioned offshore trough tracks eastward through the
weekend, periods of breezy north to west winds are expected to
develop at times across the northern Sacramento Valley and
surrounding terrain, Burney Basin, and northeast Sierra foothills.
The periods of stronger winds are anticipated late Saturday
afternoon into midday Sunday and again Sunday evening into midday
Monday, with strongest winds gusting 20-30 mph currently forecast
for Monday morning. The combination of low daytime humidity values
into the lower teens and upper single digits, limited overnight
humidity recovery, and periodically breezy to gusty winds will
introduce elevated fire weather conditions to the above areas
through Monday.

Tuesday through next week...

As the passing longwave trough flattens the ridge and introduces
broader reinforcing onshore flow to interior NorCal early to mid
next week, a slight cool down is anticipated, although widespread
Moderate HeatRisk is still expected to persist. While high
temperatures into the upper 90s to triple digits are likely to
continue across much of the region, increasing onshore flow and
the return of a more persistent Delta Breeze pattern is expected
to provide some overnight relief for Delta and vicinity Valley
locations.

&&

.AVIATION...

VFR conditions are expected to prevail over the next 24 hours.
Winds generally remain 12 kts or less at TAF sites, although some
gusts nearing 18 kts will be possible through 06z Saturday.
Stronger sustained winds up to 15 kts with gusts up to 22 kts are
otherwise expected through the Delta, gradually weakening after
12z Saturday.

&&

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

$$