Area Forecast Discussion
Issued by NWS Sacramento, CA

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000
FXUS66 KSTO 290447
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
947 PM PDT Tue Oct 28 2014

.Synopsis...
Mild weather through early Thursday. A frontal system will impact
northern interior California late Thursday into Saturday with rain
and snow and cooler daytime temperatures. Snow levels will lower
to around 4000 ft Saturday morning. Drier and warmer weather early
next week.

&&

.Discussion...
A trough moving through the Pacific Northwest with the tail of the
front spreading some light showers or sprinkles over the northwest
part of the state. A few sprinkles may make its way into parts of
Western Shasta County overnight into early Wednesday otherwise
just expect clouds over the north tonight that will help to keep
temperatures a little warmer tonight.

As the next system approaches a ridge will start to amplify a
little over California on Wednesday. The models have slowed the
pace of the system a little but both are still not quite in sink
with one another. The GFS is still a little bit faster that the
NAM. Some light precipitation may start over the northern areas
and coastal range late Thursday night out ahead of the main front
as moisture spreads over the region. The main band will come in on
Friday during the morning for the coastal range and parts of the
western Sacramento valley and then spread east for the afternoon.
There is a chance the far southeastern portions of the CWA may
stay dry for the trick or treaters but most other areas should be
wet. The coastal range and far western end of the valley will
likely see showers with possible thunderstorms developing behind
the front.

Unstable air behind the front will give the interior a chance of
thunderstorms pretty much everywhere Friday night. The low will
still be over the region Saturday morning with a chance of showers
continuing and isolated thunderstorms. Its not until Saturday
evening when the low moves far enough to the east that more stable
air move over the area and dry things out. Conditions may become
breezy to windy from the northwest to north behind the front by
Sunday morning.


.Extended Discussion (Saturday through Tuesday)

Confidence continues to increase that we`ll see a significant
winter-like system affecting the region Halloween into Saturday.
Timing of the initial frontal system moving inland has improved
with the 00Z Monday operational runs of the GFS, EC and GEM
pointing toward daytime Friday for the onset of precipitation with
showers continuing Friday night and Saturday as the upper trough
moves overhead. Moderate amounts of precipitation, gusty winds and
potentially moderate amounts of snowfall for the higher
elevations of the northern Sierra will be possible with this
system.

Trough shifts east Sunday with ridging forecast to return into
early next week leading to a return of dry northwesterly flow for
much of interior NorCal and a retreat of precipitation chances to
around the Oregon border.

JClapp/Dang


&&

.Aviation...

VFR conditions expected to continue over the next 24 hours. Scattered
mid level clouds over the northern Sacramento Valley.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$







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