Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
523 PM EST Thu Dec 22 2022

Valid 00Z Fri Dec 23 2022 - 00Z Sun Dec 25 2022

...Historic winter storm to produce widespread disruptions to large
portions of the nation heading into the holiday weekend...

...Over 280 million people, or roughly 60% of the U.S. population, are
under some form of winter weather warnings or advisories across the U.S....

...Powerful Arctic front to sweep into the eastern third of the nation
Thursday night into Friday, while temperatures will begin to rebound
across the Northern Rockies and High Plains this weekend...

...Heavy Snows to blanket the Great Lakes region into northern NY State
and northern New England...

...Significant freezing rain possible across the Pacific Northwest...


A tremendously impactful winter storm will continue to affect large
portions of the nation late this week and going into the holiday weekend. 
Winter weather hazards will stretch from border to border across the
central and eastern U.S. and from coast to coast from the east coast to
the Pacific Northwest.  The National Weather Service's Watch Warning
graphic ( https://www.weather.gov/) depicts one of the greatest extents of
winter weather warnings and advisories ever.  As of Thursday afternoon,
over 280 million people in the U.S. are under some form of winter weather
warning or advisory. This includes nearly 177 million for wind chill
warnings or advisories, 11 million for blizzard warning, 65 million for
winter storm warnings, and 500 thousand for ice storm warnings.  This
storm will likely will have increasingly widespread impacts to travel
going into the busy holiday travel time late this week, along with the
potential for power outages from the expected high winds, heavy snows,
significant icing and overall increased power consumption in places.

The powerful arctic front that brought huge temperature drops across the
Plains over the past 24 hours will be sweeping eastward across the eastern
third of the nation Thursday night into Friday. Many locations from
portions of the Northern Rockies into the Central to Southern High Plains
saw temperatures drops greater than 50 degrees in the wake of the passage
of the arctic front, including 67 degrees colder at Cheyenne, Wyoming and
72 degrees colder at Denver, Colorado.  While the temperature drops behind
the arctic front are not expected to be as great from the MS Valley into
the eastern U.S., it will still feel abruptly colder with many locations
30-40 degrees colder in the wake of the arctic front.  Widespread record
low maximum temperature are possible Friday from the Lower Mississippi
Valley, northeastward into the Tennessee and Ohio Valleys and stretching
across large sections of the east from the Southeast, through the Southern
to Central Appalachians and into the Mid-Atlantic on Friday.  In addition
to the very cold temperatures, high winds in the wake of the front will
produce dangerous wind chill readings across nearly all of the central to
eastern U.S.

In addition to the very cold temperatures, a developing low pressure
system along the arctic front over the Mid West/Great Lakes region will
produce widespread heavy snows from portions of the Mid West into the
Great Lakes on Friday.  This will be followed by active lake effect snow
showers downwind of all of the Great Lakes on Saturday as the very cold
arctic air streams across the Great Lakes.  Blizzard warnings and Winter
Storm warnings are currently in effect from the Great Lakes, Mid West,
Middle to Upper Mississippi Valley and into the Northern Plains.

Relief is in site from the very cold temperatures for areas from the
Northern Rockies into the High Plains by this weekend as temperatures will
rebound tremendously from current readings.  In many locations,
temperatures will be 40 to 60 degrees warmer by this weekend as the core
of cold air will be across the east, while the above average temperatures
currently across the Southwest spread farther to the north and east and
push across the Rockies and into the High Plains.

Not to be left out of the active winter weather across the central to
eastern U.S., there is the potential for significant icing across the
Pacific Northwest Thursday night into Friday as moisture from the Pacific
falls into low level arctic air currently entrenched across this area. 
This low level arctic air is the western extent of the arctic airmass
centered across the central portion of the nation.  It does appear that
this low level arctic air over the Pacific Northwest will warm
sufficiently by late Friday night along coastal sections to diminish the
freezing rain threat.  The freezing rain threat will continue, however,
inland through the Columbia River Valley and across areas east of the
Cascades through much of Saturday.

Oravec

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