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Good afternoon from our office in Sacramento. It is Friday, Dec 6th. It certainly felt like
winter the past two mornings as we certainly felt the cold snap. Temperatures dropped into
the 20s across much, if not, all the valley. We expect more winter weather to impact interior
northern California through next Tuesday, Dec 10th with snow accumulations and more
cold temperatures. If you follow us on social media use the hashtags coldsnap and/or Casnow
for this event. Looking at our latest weather story graphic,
major impacts with this cold storm will be low elevation snow late today through Saturday.
As a result, we have a winter storm warning in effect for most areas above 500 feet valid
from late this afternoon into Saturday, with a winter weather advisory across the central
Sacramento Valley into southern Lake county. We have had quite a few reports of snow in
northern Sacramento Valley today as of 300pm. Most snow accumulation will begin around 400-500
feet with northern areas and extreme eastern valley edges dropping slightly lower…possibly
down to around 250 feet. Below 250 feet, a rain/snow mix is likely. However, not much
if any snowfall is expected to accumulate. In any case, expect hazardous travel with
major delays. With the low snow levels, many miles of roadways
could be impacted with accumulating snow…especially I-5, I-80, and US 50.
Potential exists for valley snow beyond just the northern Sacramento Valley. The last time
Sacramento had snowfall was exactly 4 years ago, Dec 7th 2009. Even though areas throughout
much of the valley saw snow in 2009, very little to nothing accumulated.
Winds may create near whiteout conditions later tonight into early Saturday morning,
especially in the mountains.
Here is a possible snow accumulation forecast with a confidence factor above 500 feet for
late Friday into Saturday from our office in Sacramento. Our confidence in snow accumulation
above 500 feet is pretty high. The airmass has been cold leading up to this storm, and
more cold air will sink over the area due to this storm. Be prepared for significant
snowfall Friday night and into Saturday with very poor visibility. Notice the 1 to 2 feet
of snowfall over the higher Sierra Nevada. Here is a possible snow accumulation forecast
with a confidence factor below 500 feet for late afternoon into Saturday from our office
in Sacramento. Even though snow accumulations show “0” (zero) across much of the valley,
snowfall could still occur, especially the northern and eastern portions where a few
hundreths are forecast. Our confidence in snow accumulation at less than 500 feet is
medium. The ground and near surface temperatures may still be warm enough to melt the snow
before it can accumulate. In any case, be prepared for some snowfall tonight and into
Saturday. Following the cold front and clearing skies,
anticipate more cold air creeping into northern California late this weekend and early next
week. Here is an image of the 24 hour minimum temperature changes from Saturday into Sunday.
We expect temperatures to cool 5 to 20 degrees. Here is the forecast minimum temperatures
for Sunday. We expect Saturday night into Sunday to be the coldest with valley temperatures
to range from 15 to 30 degrees F, the foothills (~1000-3000 ft) 10-15 F, and the higher mountains
from negative 10 up to 15 F. These cold temperatures will depend on the strength of the northerly
winds and any cloud cover. Wind act to mix the air, and keeps night time temperatures
relatively warmer. Also, be prepared for icy road conditions from any snow melt, especially
at lower elevations. The following day, Sunday night into Monday
morning may still bring more freezing temperatures to the region. We expect these temperatures
to be fairly similar to the Sunday. Again, these cold valley temperatures will depend
on the strength of the winds and any cloud cover. Again, be prepared for icy road conditions
from any snow melt, especially at lower elevations. Enjoy the rest of your day and coming weekend,
and we appreciate your feedback and weather reports. Please be careful out there and remember
to protect the four Ps: people, pets/livestock, plants, and pipes. Follow us on our webpage
and/or social media. Please use hashtag CAsnow and coldsnap to reference this weather event.