Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 301643

943 AM PDT Wed Jul 30 2014

Moisture surge will bring a few sprinkles and thunderstorms to
portions of interior NorCal today and Thursday, and again
potentially next week. Hot afternoon temperatures continue.

.Previous Discussion...
Elevated moisture and instability over NorCal was enough to
generate some isolated showers with a few lightning strikes
earlier this morning. The showers are currently spreading north
and northeastward along the 700-500mb mean wind flow across the
eastern portion of the Northern San Joaquin Valley, Motherlode,
and Sierra...and also just west of Lake County/Coastal range.
Showers are expected to continue through the morning, where
affected areas will see some sprinkles or light rain. Lightning
activity has decreased the past couple of hours.

The ridge of high pressure over the western US will continue to
channel tropical moisture over northern California today, bringing
increased cloudiness and supporting a threat of thunderstorms
over the higher terrain for this afternoon and again on Thursday
afternoon. By Friday and Saturday, most of the energy and
moisture will move north and east of the area...limiting the
thunderstorm threat over our area.

Temperatures will remain a few degrees above normal through the
weekend, with a slight cooling trend each day as the high pressure
shifts slightly eastward and heights decrease slightly over
NorCal. A delta breeze is expected to return each night to provide
slight relief to nearby locations in the evenings. Shen

Forecast in good shape but we did make a small tweak to coverage
of slight chance of thunderstorms...adding to Motherlode zone for
early this afternoon.

Models showing some elevated CAPE around the valley nearly all
day...which will push slowly off to the east today. Hard to find a
trigger or any omega forecast to interact with the instability
over the valley so have kept the weather dry in the valley. Looks
like this will continue to result in ACCUS. We did add some slight
chance to southern foothills as moisture and instability lingers
around a bit there this morning...but overall trend is for
moisture and instability to shift to the east this afternoon with
activity confined eventually to Sierra crest per current forecast.


.Extended Discussion (Sunday through Wednesday)

The upper level high pressure over the western US will continue to
shift slightly eastward for Sunday before trying to rebuild again
for early next week. This will result in slightly cooler
temperatures for Sunday and Monday before a gradual increase in
temperatures again by mid-week to slightly above normal. A
potential for moisture to return along the mountains beginning
Monday could result in afternoon showers and thunderstorms along
the Sierra crest and eastward, as well as to our north. Right now
have left a slight chance of Sierra crest thunderstorms in Monday
through Wednesday. Shen



Mainly VFR next 24 hours all TAF sites. Isolated -RW with cigs
BKN100 in Vicinity of KSCK/KMOD through about 18z with Isolated
showers this morning Sierra and foothills. Isolated thunderstorms
developing along Sierra crest and over Shasta county mountains
after 18Z. Delta breeze around 10-15 KT with gusts to 25
KT...otherwise generally less than 15 knot.


.STO Watches/Warnings/Advisories...

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