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000
FXUS66 KSTO 241010
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
310 AM PDT Wed Apr 24 2024

.Synopsis...
Cool and unsettled weather this week. A chance for afternoon
showers and thunderstorms over the mountains today. Precipitation
chances increase Thursday and Friday as a weather system moves
through, best chances in the foothills and mountains.

&&

.Discussion...
Mostly cloudy skies cover NorCal early this morning as the large
closed low to our southwest moves toward SoCal. The large surface
pressure difference from 24 hours ago has balanced out somewhat as
cooling has spread across most of the region. Correspondingly,
onshore winds are much lighter this morning with Travis AFB
reporting under 10 kts.

Today will be an in-between systems day for NorCal as upstream
short-wave energy approaches from the Gulf of Alaska and the
closed low moves into SoCal before heading east to generate the
next round of severe weather in the Plains on Thursday and Friday.

Partly to mostly cloudy skies are expected today with cool
temperatures - similar to Tuesday`s. Afternoon thunderstorm
chances are expected to be limited to the northern mountains and
the Sierra south of Highway 50.

The next round of more widespread showers for NorCal is expected
later on Thursday into Friday as short-wave energy slides
southward behind the departing SoCal low. It`s still looking like
a relatively low-impact system with QPF of less than 0.10" in the
valley, and generally around 0.50" or less over the mountains. A
few inches of snowfall accumulation will be possible over the
higher elevations (snow levels above 6-7k ft) in the Sierra, but
travel impacts will likely be minimal.

A return to dry weather with gradually milder temperatures is
expected to begin Saturday as riding from the eastern Pacific
builds into the region.

&&

.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)...
Dry weather Sunday as weak short wave ridging moves through
interior NorCal. Upper troughing then resides off the West Coast
through midweek associated with upper low west of VRISL. This will
result in onshore flow with temperatures gradually trending down
through midweek. Series of vort maxes progged across interior
NorCal Wednesday with NBM showing slight chance POPs over the
mountains of Shasta and Plumas counties.

&&

.AVIATION...
VFR conditions over interior NorCal next 24 hrs exc isolated
MVFR/IFR possible over mtns in showers. Sfc wind mainly below 12
kts except vcnty of Delta SWly sust wind up to 18 kts possible aft
00z Thu.

&&

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

&&

$$