Scientific Forecaster Discussion

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Area forecast discussion 
National Weather Service Sacramento California
453 am PDT Fri Apr 18 2014

Synopsis...a weak frontal passage will bring a slight chance of
showers to the Sierra today. Otherwise...building high pressure
will bring fair skies and well above normal temperatures through
the remainder of the weekend. A stronger Pacific trough will
approach the coast early next week bringing increasing clouds on
Monday and a chance of rain and higher elevation snow on Tuesday.
Some areas may also see a chance of thunderstorms on Tuesday. Weak
high pressure will dry things out over the central state by
Thursday but a threat of precipitation will continue across the
north state.


Short term discussion...
a weak frontal band moving through northern California brought
isolated light showers and a few thunderstorms to northern
California last evening. This system has now moved into northeast
California. As this system continues to the southeast it may
combine with the instability of a low moving through Southern
California to produce a threat of showers or thunderstorms over
the northern Sierra this afternoon. Elsewhere...clearing skies
will allow daytime highs to again climb to well above normal for
this time of year. A flattened high pressure ridge over northern
California will bring dry conditions over the weekend. Although
daytime temperatures will be a little cooler, they will still
remain several degrees above normal for this time of year.

A stronger Pacific frontal system is forecast to approach the
coast on Monday bringing increasing cloudiness and a little cooler
temperatures on Monday with a slight threat of showers to the
Shasta County mountains. As this frontal band pushes inland late
Monday it may bring a good threat of precipitation to nearly all of
the County Warning Area.

Extended discussion (tuesday through friday)

Showers will continue across our County Warning Area on Tuesday. Slight chance of
thunderstorms in the valley on Tuesday as models indicate some
instability with the passage of the upper low. Cooler temperatures
will be noticeable as valley highs lower into the mid to upper 60s
on Tuesday. Slight warming trend begins on Wednesday and continues
into Thursday as the upper low passes eastward and ridging re-
develops. Could still have some lingering showers on Wed &
thurs...primarily over higher elevations. Jbb



VFR conditions will continue today and winds will generally be
light north to northwesterly across the valley (around 10 kts).
However, this morning will bring locally moderate gusts to the
northern Sacramento Valley for krdd and krbl vicinity with gusts
up to around 18 kts possible through 18z. Fairly dry weather today
except for the possibility of thunderstorms along the Sierra
crest. Jbb


Sto watches/warnings/advisories...