927
FXUS66 KSTO 032028
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
128 PM PDT Sat Oct 3 2026
For additional details on weather and expected impacts over the
next 7 days, please visit weather.gov/sto/briefing.
.KEY MESSAGES...
- Heat Advisory in effect till 10 PM Wednesday for the
Sacramento Valley, Delta, northern San Joaquin Valley, and
adjacent foothills.
- Widespread Moderate HeatRisk with areas of Major HeatRisk
through Thursday for the Delta, Valley, and Foothills.
&&
.DISCUSSION...
...Today through Thursday...
High pressure continues to dominate the weather pattern aloft
across the western United States. This has brought light winds,
dry conditions, and hot temperatures to Interior California.
Temperatures will be in the 90s today and tomorrow, with the
hottest conditions expected Monday through Wednesday. There is a
40 percent chance a few areas within the Sacramento Valley and
northern San Joaquin Valley that may reach 100 or above Monday
through Wednesday. Potential is there for a few areas to see at or near
record highs for this time of year. Widespread Moderate HeatRisk
is expected across the Valley, Delta, and Foothills due to the hot
and dry conditions. Areas of Major HeatRisk within portions of
the foothills and Valley through Thursday as well. Overnight
temperatures will be in the mid 60s to mid 70s for the Valley and
Foothills, with the worst overnight recoveries in the Foothills.
During this time, RH values will be in the teens to 20s, with
overnight recoveries in the 30s to lower 50s. We will start to see
a slight break in the temperatures on Thursday, with highs
backing down from the lower 100s to the 90s. The latest run of the
NBM has backed off slightly in the coverage of the Moderate
HeatRisk as well. None the less, a Heat Advisory is in effect
through 10pm Wednesday for the Valley, Foothills, and Delta due to
the widespread Moderate HeatRisk and Areas of Major HeatRisk. Try
to limit outdoor activities, check on neighbors, family, friends,
and animals, and stay hydrated.
...Friday and Beyond...
Guidance has started to show signs of the High pressure system
weakening and breaking down end of next week and into the
following weekend. Confidence in this occurring is growing as the
spread of temperatures from the 25th to 75th percentile are
shrinking for Friday and Saturday. Highs will be in the 80s to
lower 90s on Friday, with the upper 70s to mid 80s by Saturday.
Indications are there the trend of cooler temperatures continue
into Sunday and the following week ahead. This is due to an
approaching trough that has the potential to bring those cooler
temperatures and increased moisture across the area.
&&
.AVIATION...
VFR conditions continue through the TAF period for Interior
Northern California. Light and variable winds through the period,
with a few gusts to 15 kts within the Delta overnight and early
Sunday morning. SCT to BKN cloud deck around 25 kft will
gradually clear overnight before returning Sunday morning.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 10 PM PDT Wednesday for Butte County Below
1000 ft-C. San Joaquin County including Stockton-C. Solano
County including Fairfield-C. Stanislaus County including
Modesto-C. Yolo/NE Solano including Woodland-Central Colusa
County Incl. I-5-Central Glenn Co & Interstate 5-Central
Motherlode 1000-3000 ft-E. Diablo Range Above 1000 ft-Eastern
Colusa County-Eastern Glenn County-N. Motherlode 1000-3000 ft-N.
Sac Valley in Tehama County-NE San Joaquin Valley Below 1000 ft-
SW Solano County including Vallejo-Sac Metro/W. El Dorado/Amador
County-Sacramento County Delta-San Joaquin County Delta-Shasta
County Foothills 1000-3000 ft-Shasta Metro-Sierra (Tehama-
Plumas) 1000-3000 ft-Southern Motherlode 1000-3000 ft-
Sutter/Yuba counties below 1000 ft-Tracy Triangle Below 1000 ft-
W Tehama Co Foothills 1000-3000 ft-W. Glenn/Colusa Foothills
1000-3000 ft-W. Shasta County 1000-3000 ft-W. Stanislaus County
Above 1000 ft & I-5-W. Yolo County including Capay/I-505-Yolo /
Solano County Hills.
&&
$$
