Area Forecast Discussion
Issued by NWS Sacramento, CA

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000
FXUS66 KSTO 252250
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
350 PM PDT Sat Oct 25 2014

.Synopsis...
Storm system will continue to impact NorCal through this evening
with strong winds and precipitation today. Thunderstorms with
heavy rain, accumulating small hail, and maybe even isolated weak
tornadoes are possible. Snow at pass levels through tonight. Drier
weather expected by Sunday afternoon.

&&

After the main frontal passage this morning, scattered showers
with thunderstorms and high winds continue to impact much of
NorCal. Snow levels dropped down to pass levels earlier than
expected so have adjusted the forecast to reflect snow levels
around 6500 ft from this afternoon and into early Sunday. Snow
accumulations up to 10 inches are possible on Mt Lassen and
up to 4 inches possible over the higher Sierra passes.

Winds have been very strong in the Northern Sacramento Valley.
Redding and Red Bluff airports were reporting sustained winds of
23-39 mph with gusts up to around 50 mph. We also got a report
near Burney of downed trees due to the gusty winds. Wind
observations in the Southern Sacramento valley (including the Sac
Metro region) did not strengthen as much as previously thought so
have removed that area from the Wind Advisory. Also cancelled part
of the High Wind Warning across the Western Sierra Slopes...south
of Plumas County.

A line of training thunderstorms has been persistent in Western
Shasta County for most of this afternoon and will continue into
the evening. This line crosses Interstate 5 between Redding and
Lakehead so drivers should be extra cautious in this section of I-5.

Thunderstorms will continue to impact portions of the valley
through this evening. We currently have a Significant Weather
Advisory in effect for part of Butte County valid through 4 pm as
small hail, dangerous lightning, gusty winds are possible.

Due to the winds, rain and snow...we continue to emphasize that
motorists should use extra caution while driving. There have been
several reports of vehicle spin-outs and accidents due to weather
conditions.

Winds will weaken by tonight and precipitation will also diminish.
Lingering showers over the mountains could continue bringing snow
and rain/snow through Sunday morning. Expect drier and milder conditions by
Sunday afternoon. High temperatures this weekend will be in the
mid 60s to low 70s in the Valley and mid 30s to low 50s in the
mountains. Monday and Tuesday will be drier and warmer with
ridging dominating. Although there could be a slight chance of
some rain across far Northern CA...generally north of
Marysville...on Tuesday. JBB


.Extended Discussion (Wednesday through Saturday)

Amplifying ridge forecast over the western US during the middle of
next week as another trough deepens over the eastern Pacific. This
will likely keep all but the far northern portion of the forecast
area precipitation-free into Thursday. Forecast confidence
decreases later in the week as significant differences develop
between the models in the handling of the trough as it moves onto
the west coast Halloween and next weekend, though it appears much
of the region will see a chance of precipitation sometime next
Friday or Saturday.

&&

.Aviation...

Pacific cold front moves across the area today bringing gusty
winds along with areas of MVFR conditions to the valley and
widespread IFR conditions to the mountains. Wind gusts to 45 mph
will be possible til 02Z, especially over the Northern Sacramento
Valley and gusts over 50 mph will be likely over the Northern
Sierra Nevada. Scattered showers will continue through the evening
long with isolated thunderstorms til 03z.

&&

.STO Watches/Warnings/Advisories...
high wind warning until 11 pm pdt this evening burney basin /
eastern shasta county...western plumas county/lassen park.

wind advisory until 11 pm pdt this evening clear lake/southern
lake county...mountains southwestern shasta county to northern
lake county...northeast foothills/sacramento valley...shasta
lake area / northern shasta county.

wind advisory until 8 pm pdt this evening central sacramento
valley...northern sacramento valley.

&&

$$







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