Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 271749

1049 AM PDT THU AUG 27 2015

Dry weather with daytime temperatures near to a little above
normal today and Friday. Cooler temperatures beginning over the
weekend with a chance of showers over the northern portion of the
state Saturday. Dry with a little below normal daytime high
temperatures continuing through most of next week.


Temperatures running around 5 degrees above yesterday at this
time. High temperatures on Wednesday ended up a few degrees above
guidance and current guidance has trended warmer. Have raised Today`s
afternoon highs a few degrees. This gives readings at 100 degrees
or warmer at most valley spots. Otherwise...clear skies and light

Northern California remains under southwest flow aloft between
high pressure over the four corners U.S. region and an upper low
off the Pacific Northwest coast. A shortwave trough rippling
through this southwest flow is bringing some scattered cloud cover
over the northeast corner of the state at this time. Otherwise...
Norcal remains under fairs skies with temperatures running a
little warmer this morning under a slightly warmer airmass. Marine
layer remains minimal with only a very weak delta breeze so
expect daytime highs today to come in similar to yesterdays above
average readings. Changes begin on Friday as the offshore low
begins to edge towards the coast. Increasing high cloud cover and
a slight airmass cooling combined with an increased onshore flow
will bring at least some cooling Friday although highs may remain
near or a little above normal. The tail end of an early season
weak frontal band is forecast to move into northwest California
Friday night bringing a threat of light precipitation to areas
north of a Quincy to Lake county line by morning. All models keep
precip amounts on the light side but even small amounts will have
some impact on the many wildfires burning over northwest
California. Precipitation estimates currently range from about 1
to 3 tenths of an inch through the day Saturday as this frontal
band slides through. Temperatures on Saturday are expected to drop
to several degrees below normal under a cooler
cover and an increased onshore flow. A Lingering trough remains
along the west coast on Sunday for continued below normal
temperatures. Models show a secondary shortwave moving through the
Pacific Northwest on Sunday but at this time...any precipitation
from it is expected to remain north of the CWA.


A large trough pattern will stay over NorCal for the first half of
next week. Moisture associated with this trough is expected to
stay well north of our CWA so we expect slightly cool, but dry
conditions. Daytime highs will be near to 5 degrees below normal
in the extended forecast.  JBB



VFR conditions continue across the region. Winds at TAF sites will
be light around 10 kts or less. SW winds 15 to 20 kts possible
through the Delta region this evening into tonight. JBB



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