Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
256 PM EST Fri Dec 31 2021

Valid 00Z Sat Jan 01 2022 - 00Z Mon Jan 03 2022

...There is a Slight Risk of excessive rainfall and a Slight Risk of
severe thunderstorms over parts of the Ohio, Tennessee, Middle/Lower
Mississippi Valleys, and Southern Plains through Saturday morning...

...Heavy snow over the Central Plains into the Middle Mississippi Valley
overnight Friday into Saturday; Pockets of freezing rain over parts of the
Southern Plains to the Northeast, being more isolated over the Northeast...

...There is a Moderate Risk of excessive rainfall and an Enhanced Risk of
severe thunderstorms over parts of the Ohio, Tennessee, and Lower
Mississippi Valleys from Saturday into Sunday morning...

...Temperatures will be 20 to 35 degrees below average for the Northern
Intermountain Region and over the Plains, while temperatures will be 15 to
25 degrees above average from the Western Gulf Coast to the Mid-Atlantic...

An area of cold high pressure over Northern High Plains will slowly move
southward over the Southern Plains and into the Central Rockies. 
Temperatures associated with the high are 20 to 35 degrees below average
for the Northern Intermountain Region and over the Plains.  There is a
front from the Great Lakes to the Central Plains to the Northwest along
the leading edge of the cold air.  On the southern side of the front,
temperatures will be 15 to 25 degrees above average from the Western Gulf
Coast to the Mid-Atlantic.  Moisture will pool along the boundary over the
eastern two-thirds of the country.  Showers and thunderstorms will develop
along and ahead of the front from the Ohio Valley to the Southern Plains. 
Due to the dynamics of the severe thunderstorms, the SPC has issued a
Slight Risk of severe thunderstorms over parts of the Ohio, Tennessee,
Middle/Lower Mississippi Valleys, and Southern Plains through Saturday
morning.  The hazards associated with these thunderstorms are frequent
lightning, severe thunderstorm wind gusts, hail, and a few tornadoes.

Furthermore, heavy rain will be associated with these thunderstorms. 
Therefore, the WPC has issued a Slight Risk of excessive rainfall with
these thunderstorms over parts of the Ohio, Tennessee, Middle/Lower
Mississippi Valleys, and Southern Plains through Saturday morning.  The
associated heavy rain will create mainly localized areas of flash
flooding, with urban areas, roads, and small streams the most vulnerable
through Sunday morning.

More hazards lay on the north side of the front as heavy snow will develop
over the Central Plains into the Middle Mississippi Valley overnight
Friday into Saturday.  In addition, there will be areas of rain/freezing
rain along the rain/snow line from parts of the Southern Plains to Middle
Mississippi Valley overnight Friday, too.

The hazards continue on New Year s Day as showers and thunderstorms
continue along and ahead of the front.  However, the threat of severe
thunderstorms and excessive rainfall increases.  Therefore, the SPC has
issued an Enhanced Risk of severe thunderstorms over parts of the Ohio,
Tennessee, and Lower Mississippi Valleys from Saturday into Sunday
morning.  The hazards associated with these thunderstorms are frequent
lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. 
However, there is a 10% or greater probability of EF2-EF5 over parts of
the Tennessee and Lower Mississippi Valley into parts of the Southeast.

Likewise, the WPC has issued a Moderate Risk of excessive rainfall with
these thunderstorms over parts of the Ohio, Tennessee, and Lower
Mississippi Valleys from Saturday into Sunday morning.  The associated
heavy rain will create numerous areas of flash flooding.  Furthermore,
many streams may flood, potentially affecting larger rivers through day
morning.  The winter weather threat will continue as moderate to heavy
snow develops from the Great Lakes into Northern New England on New Year s
Day.  Also, there will be isolated pockets of rain/freezing rain along the
rain/snow line.

Meanwhile, snow will develop over parts of the Southwest and
Southern/Central Rockies through Saturday evening.  Furthermore, there
will also be rain and showers with embedded thunderstorms from parts of
the Southwest to Texas.  The rain and snow will generally end by Saturday
evening.  A front will begin to come onshore over the Pacific Northwest on
Sunday.  Rain and higher elevation snow will develop over parts of the
Pacific Northwest on Sunday afternoon into evening.

Ziegenfelder

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