Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Sacramento California
332 PM PDT Wed Oct 18 2017
dry and mild weather today. Rain chances along with High Mountain
snow and cooler temperatures and gusty winds Thursday and Friday.
This will be followed by a warming trend into early next week.
mild and dry weather continues today, ahead of an approaching cool
trough from the Gulf of Alaska. This system will move in late Thursday
through Friday with widespread precipitation, much cooler
temperatures and gusty southerly winds. This system has trended
wetter in the latest model runs. The wetter mountain areas may
see as much as an inch and a half of liquid precipitation while
the valley will generally see less than a quarter inch and many
locations probably a few hundredths to a tenth of an inch. Colder
air behind the frontal band is expected to lower snow levels
below the major passes on I-80/US-50 where up to 3 to 6 inches of
snow could accumulate. This along with gusts to 55 to 65 mph over
high elevations prompted the issuing of a Winter Weather Advisory
from 11 PM Thursday night to 11 am Friday morning.
Winds will also be gusty in the Sacramento Valley, especially in
the northern end. Brief gusts to 40 mph are possible Thursday
night as the cold front passes through. Strong winds will persist
longer over the mountains, with strong mid level flow.
Warm frontal clouds could return Friday night with precipitation
lingering over Shasta County through the weekend. Strong ridging
begins to build for the weekend with high temperatures warming to
the low 80s in the valley by Sunday. Ek
extended discussion (sunday through wednesday)
Upper level ridge will begin to build into northern California
late this weekend and into early next week and bring a return of
dry and above normal temperatures under clear skies. High
temperatures will range between 5 and 15 degrees above average
each afternoon through the middle of next week.
VFR conditions with light winds through 18z Thursday. Local haze/fu
MVFR visibility is possible in the Delta and surrounding
terminals for Thursday morning. Valley and ridge winds will
increase Thursday afternoon with an approaching system, especially
over the ridgetops and North Sacramento valley.
Winter Weather Advisory from 11 PM Thursday to 11 am PDT Friday
for West Slope northern Sierra Nevada.