Sierra City, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

681
FXUS66 KSTO 092053
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
153 PM PDT Wed Jul 9 2025

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

.DISCUSSION...

.SYNOPSIS...
Moderate to Major HeatRisk is anticipated across interior NorCal
Thursday through Monday. Some Delta breeze influence will bring
minor cooling over the weekend and into next week in the Delta and
adjacent Valley locations. Dry and periodically breezy weather
continues.

&&

.KEY MESSAGES...

*  Today:
 - Seasonable temperatures and dry conditions expected today
 - Smoke will continue to impact areas in the vicinity of the
   Green Fire over the next few days
 - Warming trend begins as trough moves inland and high pressure
   begins to build

*  Thursday-Friday:
 - Upper level ridge continues to build, resulting in dry
   conditions and warming temperatures with low daytime relative
   humidity and moderate to poor overnight recoveries
 - Widespread Moderate HeatRisk with areas of Major HeatRisk
   across interior NorCal
 - Locally breezy northerly flow in the northern/central
   Sacramento Valley and adjacent terrain, mainly in the overnight
   through morning timeframe

*  Saturday-Monday:
 - Continued hot and dry conditions, with widespread Moderate
   HeatRisk and areas of Major HeatRisk in the forecast for
   interior NorCal into early next week
 - There will be some Delta breeze influence over the weekend and
   into next week that will allow for minor cooling in the Delta
   vicinity
 - Upper level ridging looks to continue to be the dominating
   weather pattern into early next week

.Changes from previous forecast...
 - Temperatures and HeatRisk have trended higher for this weekend
   through early next week
 - Issuance of Heat Advisory north of Interstate 80 in the
   Valley, foothills and mountains from Friday through Sunday

&&

.AVIATION...
VFR conditions across interior NorCal next 24 hours. Periods of
breezy onshore winds with gusts up to 15 knots in the Delta
vicinity through 06z Thursday. Elsewhere, sustained speeds
generally less than 12 knots, with gusts up to 15 to 20 knots in
the northern Sac Valley after 16z Thursday. Local MVFR conditions
possible at times in HZ/FU vicinity of Shasta County wildfire,
including KRDD.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 11 AM Friday to 11 PM PDT Sunday for Burney
Basin / Eastern Shasta County-Central Sacramento Valley-
Mountains Southwestern Shasta County to Western Colusa County-
Northeast Foothills/Sacramento Valley-Northern Sacramento Valley-
Shasta Lake Area / Northern Shasta County-Western Plumas
County/Lassen Park.

&&

$$