Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 202157

257 PM PDT Mon Oct 20 2014

Frontal system will continue cooler temperatures and
precipitation chances through tonight. Thunderstorms are expected
to continue into this evening, especially across the Sacramento
Valley and Sierra foothills. An elongated frontal system impacts
northern CA with potential showers from Wednesday night into the


.Short Term Discussion (Tonight through Thursday)...
Some strong showers have developed across the Sacramento Valley
this afternoon. These storms have had relatively low tops at
around 20-25K. Not too much shear or lightning strikes with these
storms, so most storms will be heavy rain with outflow winds.
These storm are not tall enough (cold enough) for much hail. Storm
activity will continue tonight as the low center passes over
NorCal, especially across the east valley and into the Sierra.

Flat ridging moves in Tuesday with some lingering clouds, but
remaining dry. The next elongated frontal system will begin to
bring light warm frontal precip to the Shasta co. area Wednesday
night and spread southeastward Thursday, but still remaining
northward of I-80. Temperatures will remain at or below seasonal
norms.     JClapp

.Extended Discussion (Friday through Monday)
A cooler and unsettled weather pattern will continue through the
weekend. A low in the Gulf of Alaska will slowly move south and
send disturbances inland over northern California and the Pacific
Northwest. The first such weather system will move over northwest
CA early Thursday and spread light showers across the northern
Sacramento valley by Thursday afternoon/evening. By the weekend,
the main weather system will move inland over Oregon and
Washington and spread more showers into northern California. Some
discrepancy exists in the models as to how much moisture/energy
make it into the valley and how fast the system moves through. At
this time, have continued the chance of showers in the forecast
through the weekend. There`s also a possibility of light snow
accumulations Saturday night in the northern Sierra. Progressive
pattern looks to continue into early next week, but timing and
strength of systems is uncertain at this time.      Mead


A cold front pushing through the northern valley with showers and
the potential for isolated thunderstorms this afternoon and
evening. These showers are resulting in MVFR conditions over much
of the northern valley with some local IFR near stronger storms.
Erratic and gusty winds should also be expected near storms.
Showers will linger over the Sierras until midnight, then mid
level clouds will linger over the valley and mountains.    Mead


.STO Watches/Warnings/Advisories...

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