Winter Storm Warning 11, NWS Sacramento, CA

Area Forecast Discussion
National Weather Service Sacramento CA
406 AM PST Fri Mar 3 2017

.Synopsis...
Dry weather today then cooler unsettled weather over the weekend
into Monday. Drier weather returns Tuesday.

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.Discussion...
Interior NorCal will enjoy one more day of dry, warm weather
today. Valley highs will range in the low 60s around Redding and
Red Bluff, the mid 60s around Sacramento Metro region, and the mid
to upper 60s for the Stockton-Modesto vicinity. Across higher
terrain, daytime highs will be in the mid 40s to 50s.

On Saturday, we transition into a cooler, wetter pattern as a
storm over the Eastern Pacific moves into the West Coast.
Precipitation should spread across our entire CWA during the
afternoon hours. Snow levels will start off around 5000 feet on
Saturday, then lower significantly on Sunday. Expect snow levels
across Shasta County to drop around 1500 feet impacting the
Interstate 5 corridor. Across the Sierra, snow levels will range
2500 to 3000 feet and impact mountain travel. Snow levels remain
low into Monday as precipitation continues in our region. In
addition to mountain snow, gusty winds along the higher elevations
could cause white out conditions this weekend. Motorists should
realize that if they go up to the mountains on Friday when weather
is clear, then the ride home on Sunday or Monday will be impacted
by snow and wind.

Winter Storm Watch still in effect for elevations of 3000 feet and
higher. Light snow accumulations will occur between 1500 to 3000
feet. Snow totals around 3000 feet should range 4 to 10 inches
with up to 3 feet of snow near the passes. Heaviest snow will
occur on Saturday. Rain totals in the valley will range around
0.40" to a little over an inch. Precipitation will begin to taper
off late Monday into Tuesday.

JBB

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.EXTENDED DISCUSSION (Tuesday THROUGH Friday)

Extended models now in fairly good agreement showing flat ridge
over the west coast next Tuesday. A short wave trough moving
through the Pacific Northwest and Norcal, also modeled fairly
consistantly by models, will bring a threat of showers north of
about interstate 80. Moderate snow levels and limited moisture
will mean this will be a fairly unimpactful system. Upper ridge
will continue to amplify over the west coast on Wednesday but not
before one last shortwave rides over the ridge bringing a slight
threat of showers over the coast range and northern mountains.
Upper ridge may build enough by Thursday to push precipitation
threat north of the forecast area but models differ on this idea.
For now, have kept Thursday and Friday dry but subsequent models
may sag the precipitation line southward. Still looking for a
warming trend through the extended period with daytime highs near
normal Tuesday climbing to several degrees above normal by Friday.

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.AVIATION...

VFR next 24 hours. Increasing clouds northern Sacramento valley
with a slight chance of light showers after 06z Saturday.
Southerly winds to 15 knots increasing over the Sierra Saturday
morning.

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.STO WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Saturday afternoon through Monday
afternoon for Burney Basin / Eastern Shasta County-Mountains
Southwestern Shasta County to Northern Lake County-Shasta Lake
Area / Northern Shasta County-West Slope Northern Sierra Nevada-
Western Plumas County/Lassen Park.

Flash Flood Watch through Monday afternoon for Carquinez Strait
and Delta-Northern San Joaquin Valley.

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