905
FXUS66 KSTO 132143
AFDSTO
Area Forecast Discussion
National Weather Service Sacramento CA
143 PM PST Fri Nov 13 2026
.KEY MESSAGES...
- Widespread moderate to heavy rain, snow in the mountains, and gusty
to strong southerly winds today into Monday.
- Winter Storm Warning through 10 AM Saturday morning for the
Sierra and Lassen Volcanic National Park above 6000 feet
- Wind Advisory is in effect till 7 pm PST today for the
Sacramento Valley, Delta, portions of the Northern San Joaquin
Valley and into the foothills.
- Flood Advisory until 4 PM this evening for low-lying areas
along the Delta and vicinity, with coastal flooding potential
from high tides
- Another storm will bring the potential for additional rain,
mountain snow and gusty winds mid to late next week
&&
.DISCUSSION...
...Today through Saturday...
Current Satellite and Radar has a band of precipitation moving
through the Coastal Range and through the Valley this afternoon.
We will continue to see this band move into the Sierra through the
remainder of the afternoon and into the evening hours. Rain rates
may be moderate to heavy at times as it moves through the region.
Potential impacts will be slick travel conditions, minor flooding
especially over poor drainage areas and urban regions, and a low
risk for Debris Flow Concerns for the Park and Gann Burn Scars.
Total rainfall between today and Saturday is forecasted to be up
to 2 inches at higher terrain, with up to an inch possible in
parts of the Valley. Locally higher amounts can`t be ruled out
especially where stronger storms develop.
Isolated thunderstorms will be possible ahead of the main band of
precipitation, with isolated stronger storm potential. The better
chance for thunderstorms arrives later this afternoon and into
the evening. If we can increase the clearing across the area, we
can then increase the instability. As of right now, the 3pm
through 9pm timeframe is favored for any potential for stronger
storms to produce small hail, gusty winds, frequent lightning, and
possible funnel clouds where we have higher shear, enhanced
stretching, and surface vorticity maximums.
As the main band shifts into the mountains snowfall will start to
increase, with the potential for 1 to 2 hour snowfall rates at
times. Isolated higher snowfall rates of 3 inches per hour can`t
be ruled out especially where we get convective bands shifting
through. Total snowfall by Saturday morning ranges between 6 to 12
inches, with locally up to 18 inches at the higher peaks for areas
above 6000 feet in the Sierra. Up to 2 inches will be possible as
low as 5000 feet as colder air filters in overnight dropping snow
levels down. A Winter Storm Warning remains in effect through
10AM Saturday for the Sierra above 6000 feet and Lassen National
Park.
Strong southerly winds will continue to impact the Sacramento
Valley, Delta, foothills, and parts of the northern San Joaquin
Valley through 7pm. Gusts up to 45mph are expected, with isolated
gusts to 50mph possible in parts of the northern Sacramento
Valley. We went ahead an extended the Wind Advisory through the
foothills between 1000-3000 feet and parts of the northern San
Joaquin Valley due to observed reports of 40-45mph gusts. The Wind
Advisory is in effect through 7pm this evening.
Abnormally high tides continue through 4pm this evening for the
San Pablo Bay, Carquinez Strait, and Susan Bay shorelines in
Solano County as coastal flooding continues.
...Sunday and beyond...
A lull in activity is expected Saturday as the first system moves
out of the region and a secondary shifts in by late Saturday night
in Sunday morning. Further widespread precipitation is expected
across the area. Latest NBM has decreased snow totals and QPF
across the area for the system. None the less, up to an inch of
new QPF is possible, with the best chances around Shasta county.
Snow is expected at this time Sunday through Monday, with snow
levels around 6500-7000 feet Sunday and 5500-6000 feet Monday. Up
to a foot is possible for areas south of Highway 50 at the highest
peaks. Otherwise, up to 10 inches in total for areas above 6000
feet when all said and done on Monday. Potential for minor
accumulations down to 5000 feet.
Another lull in activity is expected Tuesday, before a third
system moves into the region mid next week. Uncertainty arises
with the exact timing, development, and strength of the system but
confidence has increased that we will see further widespread
precipitation across the area. As it stands right now, this system
is trending colder with lower snow levels. Probabilities to see
above a foot are 60 to 70 percent within the Sierra and southern
Cascades. Probabilities for snow levels down to 4000 feet are 40
percent at this time. QPF probabilities at this time are 60
percent for over an inch within the foothills and mountains. We
will continue to keep an eye on the mid week system as its
trending colder, snowier, and potential impactful across the
area.
&&
.AVIATION...
MVFR to VFR conditions are expected through the next 24 hours,
with periods of IFR possible due to moderate to heavy rain rates
creating low visibility. Rain will continue to overspread the
area throughout the day, with the Sacramento Sites, SCK, and MOD
clearing out slowly after 6z. Areas around RDD and RBL will
continue to see chances of rain throughout the TAF period. The
heaviest precipitation will be between 18z and 3z for the sites.
Strong southerly winds will continue through the afternoon/evening
hours for each site, with calming winds overnight. A few
thunderstorms will be possible this afternoon/evening, but
confidence remains on the lower end on development.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until 7 PM PST this evening 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-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-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-W. Yolo County including Capay/I-505.
Winter Storm Warning until 10 AM PST Saturday for Lassen
Volcanic NP-Sierra (Cal-Tuo) Above 5000 ft-Sierra (El Dorado-
Amador) Above 5000 ft-Sierra (Sierra-Placer) Above 5000 ft.
&&
$$
