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000
FXUS66 KSTO 132145
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
245 PM PDT Sat Apr 13 2024

.Synopsis...
A weak weather system brings showers, mountain snow showers, and
breezy winds this weekend. Drier and warmer weather returns next
week.

&&

.Discussion...
Latest radar scans show precipitation spreading inland across
interior northern California on this Saturday afternoon.
Temperature observations are currently trending approximately 15
to 30 degrees cooler than this time yesterday afternoon, valid at
230 PM PDT. The cooler temperatures and precipitation are
associated with a closed low that is bringing showers, mountain
snow showers, isolated thunderstorms and breezy winds this
weekend.

So far, over the past 12 hours or so, rainfall amounts of
generally a tenth of an inch to almost three quarters of an inch
of rain have been observed across interior NorCal. Additional
amounts of 0.25"-1" are forecast through Sunday, heaviest in
Shasta County and in the foothills. Locally heavier amounts would
be expected with any thunderstorms that develop. The National
Blend of Models (NBM) probabilities for thunderstorms are around
10 to 20 percent, mainly in northeastern Shasta County, northern
San Joaquin Valley and in the Motherlode.

Snow showers will also bring minor impacts to the mountains today.
The NBM shows a 10 to 50 percent probability of snow amounts of 4
inches or greater in the mountains above 6000 feet, and a 50 to
65 percent probability of snow amounts of 8 inches or greater up
at Lassen Peak through Sunday evening. Expect periods of slick and
snow covered roads, with travel delays from possible chain
controls through Sunday. Snow levels will be around 3500 to 4500
feet. People should check road conditions and the forecast before
traveling in the mountains.

Cool temperatures will continue this weekend, then warmer and
drier weather returns next week with rising heights aloft. By
Tuesday, daytime high temperatures are expected to return to the
mid to upper 70s in the Valley.

&&

.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)...
Ensembles and clusters depict an upper ridge pattern across the
region through the extended period. This will result in dry
conditions and above normal temperatures (10-15 degrees above
climatology). The NBM is currently showing a 55-80% probability of
high temperatures of at least 80 degrees across the Valley
Wednesday through Saturday. Daytime temperatures will be reaching
into the low to mid 80s in the Valley, with mainly 60s and 70s
over the foothills and mountains.

&&

.AVIATION...
Areas MVFR in the vly, with areas LIFR over mtns, next 24 hrs in
SHRA and mtn -SHSN. Snow lvls above 2500-3500 ft this evening. In
Central Vly, areas easterly sfc wind up to 20 kts with lcl gusts
to 30 kts possible thru 03z Sat. Lcl SWly sfc wind gusts up to 40
kts possible over SierNev.

&&

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

&&

$$