378
FXUS66 KSTO 171948
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1248 PM PDT Tue Mar 17 2026

.KEY MESSAGES...

 - Dry weather with well-above normal temperatures expected
   through the week with Minor to Moderate HeatRisk; Hottest
   Thursday-Friday

 - Cooling to just above normal temperatures this weekend with
   chances for light precipitation and continued cooling early
   next week

&&

.DISCUSSION...

...Today-Wednesday...
High pressure will continue to strengthen with warming
temperatures each work day. As such, high temperatures will
continue to be well above seasonal normals across the region.
Minor HeatRisk is widespread through Wednesday, with Moderate
HeatRisk beginning to develop for patches of the western Central
Valley on Wednesday. The Extreme Forecast Index (EFI) continues
to show impressive shift of tails for high temperatures across the
region for all of this week, and the upper level high pressure
strength remains impressive in ensemble forecasts. Overnight
recoveries are helping keep the worst of HeatRisk values at bay,
with relief expected overnight each day this week. High
temperatures in the mid 80s to low 90s expected across the Central
Valley with incremental increases in temperatures each day.

...Thursday-Monday...
Thursday into Friday will be the hottest days this week with
minor to moderate HeatRisk in the Valley and Delta and widespread
low 90s. Current forecast have a 60-90% chance of highs over 90
degrees over the Central Valley, highest over the Delta and
northern San Joaquin areas. Overnight relief remains through the
back end of the week with overnight lows in the 50s. Temperatures
cool later this weekend but will remain above normal. By Monday,
forecast point to continued cooling with only minor HeatRisk
south of Interstate 80 and highs in the mid 70s to mid 80s.

If you are outside or planning outdoor activities this week,
please remember to drink plenty of water and wear sunscreen. As
this is an anomalous heat event, individuals may not be fully
acclimated to the emerging heat. Local waterways are also running
very cold due to snowmelt.

&&
.AVIATION...

VFR conditions are expected for the next 24 hours. Surface winds
generally around 5-12 kts.


&&

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

$$