000
FXUS66 KSTO 302212
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
312 PM PDT Thu Mar 30 2023

.SYNOPSIS...
Drier weather expected Friday. Mainly mountain precipitation
chances return over the weekend and persist into next week with
temperatures remaining below average.

&&

.Discussion...
The upper low has shifted over central California, with radar
indication some lingering showers over the the northern Sierra
south of US Highway 50. Scattered cumulus clouds have developed
over much the rest of the area this afternoon, with dry conditions.
CAMS models show the potential for some showers over Shasta
County and western Plumas County this evening and tonight,
though. Snow levels of 4000-4500 feet will mean higher elevations
will see snow showers, with a couple inches of accumulation
possible. There was some patchy Valley fog this morning, but HREF
suggest the probability of fog is lower overnight into Friday
morning, so mainly expect some morning mist.

Short-wave ridging moves through on Friday with dry weather
expected across most of the area. While temperatures will be a
little milder compared to the past few days, readings will still
be unseasonably cold, and continue this way into the weekend.

A low-impact system is expected to brush across the region on
Saturday into early Sunday bringing some showers to the northern
Sacramento Valley and the mountains north of I-80. Snow
accumulations should be light. A colder and more significant
trough is forecast for Sunday into early next week which may bring
a return of snow to the Sierra by Sunday afternoon. Current
snowfall probabilities into early next week for Donner Pass on
I-80 are for an 80% chance of 8 inches of snow, with a 50% of a
foot.

&&
.EXTENDED DISCUSSION (Monday THROUGH Thursday)...
An upper low will drop from the Pacific Northwest into the Great
Basin region early next week. This will keep unsettled conditions
over interior NorCal through Tuesday, mainly over the foothills
and mountains. Additional precipitation amounts will range from
less than 0.15" across the foothills to around 0.25-0.40" over the
Sierra early next week. Additional snowfall accumulations of 3-6"
are possible in the Sierra Monday-Tuesday. Light snow will be
possible in the upper Sierra foothills early Monday morning as
snow levels drop to 1500-2000 feet. Cold overnight lows are
possible early next week, with Valley lows generally in the low to
mid 30s; coldest readings on Tuesday. Daytime high temperatures
will remain below seasonal normals through the extended period,
with a slight warming trend possible late next week.

&&

.AVIATION...
General VFR conditions next 24 hours, except for local MVFR
conditions associated with afternoon cumulus and/or showers. Light
snow showers continue over the Sierra, and will be possible
across portions of the northern mountains after 00Z Friday.
Surface winds generally below 12 kts.


&&

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

$$