372
FXUS66 KSTO 162006
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
106 PM PDT Sat May 16 2026

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

.KEY MESSAGES...

 - A Red Flag Warning is currently in effect for the Valley and
   Delta below 1000 feet, and continues until 8 PM Monday.

 - Critical fire weather concerns for the Valley & Delta, with
   gusty north winds and low humidity. Strongest winds Saturday
   night through Sunday along and west of the I-5 corridor.

 - Above-normal temperatures continue through the forecast period
   with Minor to Moderate HeatRisk.

&&

.DISCUSSION...

...Today & Sunday...
Continued widespread Minor HeatRisk across the Valley today with weak
ridging in place over interior NorCal. Highs are expected to be in the
low to mid 80s across the Valley, with mountain/foothill highs in the
60s to mid 70s. North to east winds will continue to intensify throughout
the day today, with peak wind speeds and gusts expected Sunday. Peak
sustained speeds will be in around 20 to 30 mph in the Valley and Delta,
with gusts up to 40 to 50 mph. Strongest winds expected along and west
of I-5. To this point, we have issued a Wind Advisory for portions of
the Valley and Delta from 11pm tonight until 8pm Sunday. Relative humidities
trend lower today and again Sunday, with values in the single digits
to teens expected in the Valley starting Sunday. Due to these conditions,
a Red Flag Warning remains in effect through 8pm Monday.

...Next Week...
Winds will begin to trend weaker on Monday, however daytime relative
humidities are still expected in the single digits. Overnight maximum
humidities will be slow to recover Sunday night into Monday, with values
in the 30s to 50s. Over the mountains and through gaps and canyons,
north to east winds will gust 40 to 50 mph into Monday as well. Tuesday
sees a return to lighter winds across the area, as well as improving
overnight recoveries in relative humidity; however, a warming trend
is expected, along with daytime humidities that will remain quite low.
Widespread single digit to low teen relative humidity values are expected
through most of the week, along with increasing areas of Moderate HeatRisk.
Slight improvements in daytime humidities, especially near the Delta,
are expected Thursday and Friday at least, but elevated fire weather
conditions will likely remain in the Valley throughout next week. Please
continue to practice fire safety, and monitor your latest forecast to
stay up to date at weather.gov/sacramento.

&&

.AVIATION...

VFR conditions are expected over the next 24 hours. North-
northwest 15-20 kts over the Valley and Delta with gusts 20-35
kts through tonight, increasing to 20-30 kts with gusts 30-40
kts after 12z Sunday. Strongest wind gusts expected over the
Sacramento Valley and Delta. Northeast wind gusts up to 20-30 kts
over the Sierra through tonight, becoming northeast to east 20-35
kts with gusts up to 35-50 kts after 12z Sunday.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM PDT Monday 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-Eastern Colusa
County-Eastern Glenn County-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 Metro-Sutter/Yuba counties
below 1000 ft-Tracy Triangle Below 1000 ft-W. Stanislaus County
Above 1000 ft & I-5-W. Yolo County including Capay/I-505.

Wind Advisory from 11 PM this evening to 8 PM PDT Sunday for
Butte County Below 1000 ft-C. Solano County including Fairfield-
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-SW Solano
County including Vallejo-Sacramento County Delta-San Joaquin
County Delta-Shasta Metro-Sutter/Yuba counties below 1000 ft-W.
Yolo County including Capay/I-505.

&&

$$