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Area forecast discussion
National Weather Service Sacramento California
837 PM PST Mon Feb 27 2017

Synopsis...
flooding concerns continue as runoff from recent rain continues
to work its way downstream adding stress to waterways. A few
mountain showers linger into early Tuesday, then dry weather with
warming trend through the end of the week.

&&

Discussion...
a few light showers persist over eastern Tehama/Shasta counties
this evening. A weak shortwave will drop southward late this
evening and into the early morning hours and may help to keep
showers going...mainly for eastern Shasta, Tehama and northern
Plumas County. The activity is expected to end after midnight.

Temperatures will cool off into the 30s for the Central Valley
overnight to the teens and 20s for the mountains. Another cool
day will be on tap with temperatures mainly in the mid to upper
50s for the valley to the 30s and 40s for the mountains. Other
than a few possible snow flurries near the crest in the afternoon
the region will by dry and under light northwest to north flow.

Previous discussion...
another beautiful day in the valley with scattered clouds across
the mountains this afternoon. Shower activity has tapered off
since this morning with just a few showers across the Sierra,
south of Highway 88. Chain controls have come down across the
passes. Last shortwave will drop south into norcal later this
afternoon and evening. This may lead to a few additional showers
across Shasta County, coastal range, and the northern Sierra
through the evening hours. Not much moisture to work with so
additional accumulations will remain light with snow levels around
2000-3000 feet.

High pressure will build across the region into mid-week with dry
weather. Temperatures will gradually warm with valley highs back
into the 60s by Wednesday, 50s for the foothills, and 30s-40s
across higher elevations. Clear skies overnight will continue
chilly morning lows with perhaps a few patches of frost in the
valley.

Ceo

&&
extended discussion (friday through monday)

Broad upper ridging over norcal Friday progresses as upper trough
in the epac pushes through over the weekend. Models keep precip
threat generally north of I-80 Saturday, then show more
widespread precip Sunday. Significant model differences exist
with depth of system and how quickly it progresses. Oper GFS
showing deeper, slower, and much wetter system compared to the
Euro. By Monday, even the GFS though is showing drier weather.
With forecast confidence limited attm, have trended towards a
model blend for pops. Cooling trend expected into the weekend then
temperatures rebound some on Monday.



&&

Aviation...

Upr trof movs into grt basin as upr rdg and assocd nwly
flow blds inld ovr norcal. VFR conds nxt 24 hrs exc isold
MVFR/IFR poss in mtn shwrs til arnd 09z Tue.

&&

Sto watches/warnings/advisories...
Flash Flood Watch through late Thursday night for Carquinez
Strait and Delta.

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