Area Forecast Discussion
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FXUS66 KSTO 222305

305 PM PST Mon Dec 22 2014

Dry weather will continue through Wednesday morning as high
pressure remains in control. Areas of morning fog are likely
across the Valley both Tuesday and Wednesday. The next system
will arrive during the day on Christmas Eve with precipitation
returning to the area through Christmas morning. Dry weather will
return for the remainder of Christmas Day into Friday.


High pressure will remain in control ahead of Pac NW trough
dropping toward the region Christmas Eve into Christmas. Dry
weather will continue as ridge begins to flatten and shift to the
east. Only weather of consequence through Wednesday morning will
be morning valley fog. Suspect fog Tues morning will not spread as
far north in the valley as this morning (just south of Redding)
as NNW winds will pick up a bit tonight. Another round likely late
Tuesday night into Wednesday morning. Fog may linger through the
day as southerly flow ahead of system pushes moisture northward.

System then approaches during the day Wednesday with precip
overspreading the area from NW to SE. Models in decent agreement
with progressive nature of system. Fast moving system will limit
precipitation amounts with majority falling overnight Wednesday before
tapering off Christmas morning. Totals will range from a few
hundredths to 0.25" in the valley and 0.25 - 1" in the
foothills/mountains. Expect impacts to be limited to the mountains
where snow levels will drop to around 4000-4500 feet. Accumulating
snow likely above 5000 feet with totals of 3-8." This will likely
cause some travel headaches and possible chain controls for anyone
traversing the Sierra Wednesday night. May need an winter storm
advisory in the future to cover. Dry weather moves back in during
the remainder of Christmas Day with partially clearing skies.


.Extended Discussion (Friday through Monday)

Ridging over the Eastern Pacific on Friday will keep our region
dry with daytime highs near to slightly above normal. Extended
models are showing a storm system that rides over that ridge and
moves southward towards NorCal on Saturday. The ECMWF has this
system being stronger than the GFS and tracking more directly into
our CWA. The 12z GFS showed the system just brushing our region,
but it looks like the 18z GFS is trending more towards the EC. We
have slight chance to chance of precipitation over the weekend,
primarily for the mountains. Snow levels could be fairly low
(around 3000 ft or locally lower) and may impact some of the
foothill regions. However, precipitation amounts look to be light
at this point. Post holiday travelers over the mountains should
stay tuned for details.  JBB



Some stubborn low clouds persist in the valley south of KBAB
(Beale AFB). KSAC and KSMF have recently cleared, but KMHR, KSCK,
and KMHR are still under ceilings. They are expected to scatter
out by 0z. BR and fog return tonight, generally after 06z. Northerly
winds should limit development up around Redding and Red Bluff.
The fog/stratus should be favored in sheltered areas east side of
Valley and stay south of Chico. Expect locally dense fog at times
and that low clouds will linger through much of the morning with
improving conditions between 20-23z. JBB


.STO Watches/Warnings/Advisories...

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