Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 PM EST Mon Feb 20 2023

Valid 00Z Tue Feb 21 2023 - 00Z Thu Feb 23 2023

...A major winter storm will spread a large swath of heavy snow from the
West Coast to the Northeast through Thursday...

...Clipper system to bring light to moderate snow to the Upper Midwest,
Great Lakes and interior Northeast...

...Widespread record breaking cold in the West and record breaking warmth
in the East are possible on Wednesday and Thursday...

A shortwave trough will rapidly amplify while it digs into the West over
the next couple of days. This strong upper-level energy will bring with it
a substantial supply of Pacific moisture. An arctic draped front will
develop over top of the surface wave and shift southward beneath the
developing upper low, providing the anomalously cold air needed for a
major winter storm to unfold over the northern tier of the country this
week. A southern stream trough in the Southwest will enhance the pressure
gradient over the West and Midwest leading to strong winds in those areas.
While subtle shifts in the storm track remain possible, confidence is high
that this winter storms will be extremely disruptive to travel, livestock,
and recreation in affected areas.

Heavy snow and strong winds will develop over the Northern Rockies tonight
and spread southward across the Central/Southern Rockies on Tuesday and
Wednesday while the upper trough digs into the West. The surface low
pressure system will move into the Plains on Tuesday night and will spread
heavy snow, strong winds freezing rain across the Northern Rockies, Upper
Midwest, Great Lakes and interior Northeast on Wednesday. Winds gusting in
excess of 30mph may cause blizzard conditions over portions of the West
and Midwest on Wednesday with power outages and tree damage possible. Snow
totals between 2-4 feet with locally higher amounts are possible in the
Western mountains, while 4-8 inches of snow is possible from the
Northern/Central Plains to the interior Northeast by Wednesday evening.
Snow and ice are expected to ramp up over the Upper Midwest, Great Lakes
and Northeast Wednesday night into Thursday when the bulk of the snow ice
are expected to accumulate leading to treacherous travel conditions.

Very cold temperatures are likely from the West Coast into the Northern
Plains behind this system with record lows and dangerous wind chills
possible. The potential also exists for flash freeze in portions of the
Northern Rockies. Very warm temperatures are likely to expand across the
Southeast and Mid-Atlantic on Wednesday and Thursday prior to the arrival
of southern stream energy. Temperature records are expected to be tied or
broken in the East and West as a result of this highly amplified pattern.

Kebede

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