Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
234 PM EST Tue Dec 22 2020

Dec 23 2020 - 00Z Fri Dec 25 2020

...Snow and gusty winds likely across the Northern Plains and Upper Great
Lakes through early Thursday...

...Threat of damaging wind gusts and heavy rain shifts toward the eastern
third of the country by late Christmas Eve...

A surface low pressure system currently moving across the northern High
Plains is forecast to track eastward into the Upper Midwest on Wednesday,
spreading a variety of weather and hazards to the central CONUS. First,
snow is likely across the northern Plains tonight, with higher elevations
of the Northern/Central Rockies experiencing a few inches of snow as well.
Winds are expected to ramp up this evening as the surface low continues to
strengthen. High Wind Watches and Warnings are in place across much of the
northern and central High Plains.

Also on Wednesday, snow is likely on the backside of the low pressure
system for the Upper Midwest and Upper Great Lakes region. Accumulations
of several inches are expected for northern Minnesota, Wisconsin, and the
Upper Peninsula of Michigan through Thursday morning. Snow combined with
gusty winds could lead to lowering visibility and thus potentially
treacherous travel conditions. Farther south, moisture from the Gulf of
Mexico will increase on Wednesday, leading to rain and thunderstorms ahead
of the strong cold front associated with the low pressure system. Rainfall
totals of over an inch are expected for portions of the Lower Mississippi
Valley into the Tennessee Valley through Thursday morning, with strong
thunderstorms possible as well. By Thursday evening, strong winds and
heavy rain are expected to enter the central Appalachians and Northeast.
This rainfall on top of an abundance of fresh snow could lead to flooding
concerns across the region. Another concern is the added weight that rain
will put on top of homes and buildings where over a foot of snow still
lies.

In terms of temperatures, the strong cold front will bring much below
average temperatures to the central U.S. and Rockies on Wednesday.
Meanwhile, much warmer than average temperatures (by 15 to 30 degrees) are
likely into the Ohio Valley, Great Lakes, and East Coast through Thursday.
These warm temperatures throughout the Northeast will help increase the
flooding threat as fresh snowpack melts into nearby streams and rivers.

Elsewhere, with warm and dry conditions over the next couple days in the
Southern High Plains, elevated risks of fire weather are in place there.
Additionally, fire weather conditions could become critical over portions
of Southern California on Wednesday.

Tate/Snell