000
FXUS66 KSTO 281304 CCA
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
349 AM PDT Sat May 28 2022



.Synopsis...
Slightly below normal temperatures through the holiday weekend.
Scattered showers and isolated thunderstorms over the Sierra,
northern Sacramento Valley and surrounding mountains into the
early evening. Dry and breezy conditions return early next week
with a warm up through mid-week.

&&

.Discussion...
Leading short wave with trough approaching the West Coast has
brought a few sprinkles and light showers to NorCal overnight.
Most locations have reported just a trace, but a few foothill and
mountain locations have gotten a few hundredths.

Main upper low will swing through the Pacific Northwest this
afternoon with trough extending south over NorCal. This will
continue the cooler conditions and breezy onshore winds. As the
the system moves through expect scattered showers over Shasta
county, spreading south over the northern Sierra into the
afternoon. Isolated thunderstorms will also be possible over
Shasta county, the southern Cascades and northern Sierra this
afternoon and evening. Instability appears to be on the low side
at this time, so not expecting widespread thunderstorm activity,
but possibly some isolated small hail. Best chances as highlighted
by HREF and CAMS will be over eastern Shasta and Tehama counties,
including Lassen Park. Rainfall amounts are expected to be light
with little in the Valley and less than 0.25 inches over the
mountains. Although, there could be some locally heavier amounts
in stronger storms. Snow levels will remain above 8,000 feet, so
not expecting any snow at pass level or below.

Ensembles and clusters show the upper low moving into the Great
Basin Monday, as this occurs onshore gradients will reverse and
become offshore. The EFI is highlighting portions of northern
California for elevated north winds Monday and Tuesday with
gusts up to 30 mph. Strongest winds are expected over the
Northern/Central and Western Sacramento Valley. This will likely
bring elevated fire weather concerns back to the area Monday and
Tuesday. Valley temperatures warm back into the 90s by Tuesday
next week.

&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)...

Dry and warm Wednesday as upper ridge moves through. Several
short waves progged into NorCal Thursday into Saturday bringing a
threat of showers to mainly the mountains of Shasta county.
Cooling trend expected through the extended with highs around 10
to 15 degrees above normal Wednesday, lowering to near to slightly
below normal by Saturday.

&&

.AVIATION...

Mainly VFR exc lcl MVFR/IFR cigs in shwrs, mostly ovr mtns. Isold
tstm poss btwn 21z-03z tda. In Cntrl Vly areas Sly sfc wind gusts to
25 kts. Vcnty of Delta, SWly sfc wind gusts up to 35 kts poss. Ovr
mtns, areas of SWly sfc wind gusts up to 40 kts poss.

&&

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

$$