Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 162208
Area Forecast Discussion
National Weather Service Sacramento CA
208 PM PST Mon Jan 16 2017
Dry through Tuesday, then a series of winter storms will begin
Wednesday and continue into early next week.
An amplified ridge of high pressure remains situated over Northern
California. Mostly clear skies aloft along with light surface
winds allowed for extensive stratus and fog to develop across
much of the Central Valley from about Chico southward this
morning. With a significant temperature inversion in place, fog
and stratus were slow to burn off today, and even as of this
writing remains banked up along the Sierra foothills. Fog will
likely make a return tonight as the weather pattern will not have
changed much. Hi-resolution models actually suggest fog filling
much of the Central Valley Tuesday morning, all the way north to
The next storm system may begin bringing warm advection
precipitation to the Shasta County mountains as early as Tuesday
evening. The primary frontal system is expected to move through
the region Wednesday and Wednesday night, with periods of moderate
to heavy rain and gusty winds along with heavy mountain snowfall.
Snow levels are expected to be primarily 4000-5000 ft with this
storm, with over a foot of snow accumulation possible over the
higher elevations. Rainfall totals of 0.50 to 1.50 inches are
expected across the Valley, with 1 to 2.50 inches over the Sierra
up to the snowline.
Additional storm systems are expected in the extended period. None
of the storms appear to be as strong or wet as last week`s storms.
However, with soils still saturated and rivers and streams still
running high, any additional rainfall will bring localized
flooding concerns. The primary impact with these storms do appear
to be related to mountain snow however.
.EXTENDED DISCUSSION (Friday THROUGH Monday)
A couple Pacific frontal systems impact interior northern
California Friday into Monday with wind, rain, and mountain snow.
The first system impacts the area with some decent precip totals
and strong wind with the potential for some snow into the upper
foothills Friday night into Saturday. Scattered showers possible
Saturday, tapering off Saturday night as weak upper ridging moves
through. Another wet Pacific system progged to impact the area
Sunday into Monday bringing more significant rain and wind along
with relatively low elevation snow.
Friday into Monday: The Shasta county mountains could see 3 to 5
feet of new snowfall above 2500 feet while the Sierra and Coastal
Range could accumulate 2 to 4 feet above 3500 to 4000 feet.
MVFR stratus and/or IFR fog is lifting this afternoon over
foothills south of I-80 and adjacent Sac/SJ Valley areas.
Widespread IFR/LIFR conditions in stratus/fog will likely
redevelop tonight into early morning over southern Sac and
northern SJ Valley with IFR and patchy LIFR northward of Sutter
Buttes. Slow erosion of stratus/fog will keep it around into mid
Tue afternoon for interior Valley. JClapp
Winter Storm Watch from Wednesday afternoon through Thursday
morning for West Slope Northern Sierra Nevada-Western Plumas