Area Forecast Discussion
Issued by NWS Sacramento, CA

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FXUS66 KSTO 211649

949 AM PDT Tue Oct 21 2014

Dry zonal flow will persist through Wednesday afternoon with some
high clouds at times. An elongated frontal system impacts northern
CA with potential rain from Wednesday night into the weekend.
Chances for the areas south of the I-80 corridor to receive
precipitation increase Friday and Saturday. Significant rainfall
is possible over the far northern sections of the state through


.Short Term Discussion (Today through Friday)...
Weak ridging over the area bringing a break in precipitation today.
Local patchy fog around Sacramento and some mountain valleys like
Chester this morning with moisture from yesterdays rain and clear
skies and cool temperatures this morning. Temperatures this
morning are running about 5-10 degrees cooler than yesterday
morning. Afternoon temperatures should warm up similar to
yesterday with mostly sunny skies. Temperatures will be a little
warmer on Wednesday with highs in the low to mid 70s in the Valley
and 50s and 60s in the mountains. The weak ridge shifts east as
the trough deepens late Wednesday. Precipitation is expected to
enter the Coastal range around Wednesday evening and spread
southeast to around the I-80 corridor on Thursday morning.
Precipitation will continue on Thursday...mainly North of I-80.
The trough continues to deepen along the west coast on Friday. The
front may become more north-south oriented oriented on Friday
continuing the rain along the coastal range and Shasta county but
not much farther east. Snow levels are expected to be above 8500
feet Thursday and Friday.

Previous Discussion...
Friday night and Saturday is when the front pushes inland given
areas the greatest chance of widespread rain over the entire
interior along with some higher elevation snow and windy
conditions. Significant rainfall is likely over the mountains of
Shasta county into the weekend.

.Extended Discussion (Saturday through Tuesday)

Timing is still not consistent but models do end up bringing a
decent system through the interior Friday night and Saturday. Both
the European and GFS indicate rain spreading through the interior
Friday night. The GFS is a bit faster clearing out during the day
on Saturday while the European tries to linger the system around
into Sunday. This system in addition to the higher elevation snow
and windy conditions will likely bring thunderstorms to the

The European then develops a ridge over the area while the GFS
keeps a zonal flow pattern over the Pacific. If the GFS pattern
works out then some more rain for the far northern sections of the
state will be possible by Tuesday of next week.



Generally VFR conditions in the valley today with decreasing
clouds and winds generally 10 kt or less.


.STO Watches/Warnings/Advisories...

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