Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
456 AM EDT Sun Oct 25 2020

Valid 12Z Sun Oct 25 2020 - 12Z Tue Oct 27 2020

...Widespread snowfall across the northern Rockies and the northern Plains
today will push south into the central/southern Rockies and then turn into
an ice-storm for the southern High Plains on Monday and early Tuesday...

...Record cold temperatures continue to engulf the Rockies and the Plains
over the next few days...

...Critical to extreme fire risks and high wind threat over portions of
California; elevated to critical over the southern Rockies...

A low pressure system interacting with a surge of arctic air from western
Canada continues to deliver widespread snowfall from the northern Rockies
to the northern Plains early this Sunday morning.  As the entire storm
system continues to push southward, moderate to heavy snow is expected to
develop in the central Rockies and central Plains today before turning
into mixed precipitation over the southern High Plains on Monday into
early Tuesday.  More than a foot of snow with gusty winds and plummeting
temperatures is forecast for the higher terrain across the central Rockies
while a wide swatch of 6 inches or more of snow is expected across much of
the central to southern High Plains.  Lighter amounts of snow and wintry
mix will also extend all the way into the upper Midwest.  Temperatures
will fall to record levels from the interior western U.S. to a large
portion of the Great Plains for the next couple of days due to this early
season Arctic blast.  Much of the northern and central Rockies are
forecast to witness sub-zero temperatures Sunday and Monday mornings.  In
addition, strong winds behind the Arctic front will cause blowing and
drifting of snow with blizzard conditions possible in the windiest
locations.  Bitterly cold wind chills ranging between -10 and -20 are also
expected in portions of the northern Rockies and northern Plains.  This
will be in stark contrast with high temperatures still in the 90s over
western Texas today!

Dry air and gusty winds associated with the large arctic high pressure
system are expected to trigger Santa Ana winds that could raise fire
danger to extreme levels for parts of California.  Conditions in
California will be most critical on Monday as the strong cold front is
forecast to bring high winds and low humidity down from the Great Basin. 
Winds are forecast to be strong enough to result in downed trees and power
outages.  Wind advisories have been issued for the entire Bay Area and
High Wind Watches along the higher elevations of southern California. 
Farther east, elevated to critical fire risks can be expected over the
southern Rockies.

Meanwhile, colder air is filtering into the East Coast behind a cold
front.  The front is forecast to stall across the Southeast, allowing
showers and some thunderstorms to ride up the front toward the
Mid-Atlantic today.  The rain should be moving off the coast Sunday night
leading to mostly fine and warm weather over the Southeast on Monday. 
However, some tropical downpours and thunderstorms are expected to
continue over southern Florida into early next week as Tropical Storm Zeta
forms over the western Caribbean Sea in this record-breaking hurricane
season.  Residents along the Gulf Coast should continue to monitor the
latest forecasts for Zeta from the National Hurricane Center throughout
the weekend and into next week.

Kong/Mullinax


Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php