Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
331 PM EST Wed Dec 08 2021

Valid 00Z Thu Dec 09 2021 - 00Z Sat Dec 11 2021

...Developing winter storm will produce the first widespread and
significant snow of the season across parts of the Sierra Nevada,
Intermountain West, Central Rockies, and Central Plains through Friday...

...Slight Risk of Severe Weather for parts of the
Mississippi/Tennessee/Ohio Valleys on Friday into Friday night...

...Light snow possible across the Northeast tonight and Upper Great Lakes
on Thursday...

...Potentially record-breaking warm temperatures to build across the
south-central, Midwest and eastern United States...

The main weather story for the latter part of the work week will be a
developing winter storm that is expected to impact much of the western
mountain ranges and central U.S.. Short-wave energy, currently way out in
the Pacific, will amplify and phase with a southern stream system as it
enters the CONUS Thursday morning. Strengthening of the upper-trough will
lead to the development of a surface wave over the Intermountain West.
This developing system will produce a swath of 8-12 inches of snow
extending from the Sierra Nevada, through the Intermountain West and into
the Central Rockies on Thursday. Locally higher amounts are likely over
the highest elevations of Utah and the northern Colorado Rockies.
Meanwhile light snow will fall over parts of the Northeast and Great Lakes
tonight and tomorrow, respectively, behind one system departing into the
Canadian Maritime and another moving across central Canada. Additional
snow will fall over the Central Rockies and Utah mountains on Friday as
the surface low begins to deepen and ramp up precipitation over the
Central Plains. Between 2-3 feet of snow is expected to accumulate over
much of the Central Rockies by Saturday morning. A swath of snow, on the
magnitude of 4-8 inches, will develop in the cold sector of this system
from the Front Range across the Central Plains and into the Upper
Mississippi Valley on Friday. Light snow continues for the Cascades
through Friday as well. Scattered thunderstorms are expected to overspread
much of the Deep South into the Midwest on Friday as the deepening system
develops into a dynamic mid-latitude cyclone; tapping into rich moisture
from the Gulf of Mexico. Severe Thunderstorms are possible Friday into
Friday night across parts of the Lower/Middle Mississippi Valley and the
Tennessee/Ohio Valleys due to increased instability caused by this system.
Heavy snow is forecast to spread into the Upper Midwest/Great Lakes by
Friday evening.

The approaching winter storm will generate a plume of anomalously warm air
into the south-central U.S. and Midwest on Thursday and Friday before
spreading that warmth into the eastern third of the country on Friday
night into Saturday. Widespread temperature records may be set over much
of eastern/central Texas through to the Lower/Middle Mississippi Valley on
Friday as temperatures are expected to be between 20-30 degrees above
average. Record breaking temperatures are likely to arrive over the
eastern third of the country Friday night and Saturday with lows across
the Southeast through Ohio Valley Friday night likely to be 25-30 degrees
above average. Elevated Fire Weather Risk is in effect for parts of the
Southern Plains over the next couple of days as the developing winter
storm produces dry and windy conditions across the region.

Kebede

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