Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
319 AM EST Tue Feb 22 2022

Valid 12Z Tue Feb 22 2022 - 12Z Thu Feb 24 2022

...Significant winter storm impacting areas of the Great Lakes into the
Northeast on Tuesday into Wednesday morning...

...Risk of Excessive rainfall and severe thunderstorms increasing from the
Lower Mississippi to Tennessee/Ohio Valleys from Tuesday into Wednesday...

...a second significant winter storm impacting areas of the Southern
Plains into the Ohio Valley on Wednesday into Thursday...

...Temperatures will be 20 to 30 degrees below average over the Northern
Tier States; In contrast, temperatures will be 10 to 25 degrees above
average over Lower/Middle Mississippi Valley into the Ohio Valley...

A strong wave of low pressure over the Middle Mississippi Valley will move
northeastward to Eastern Canada, while the associated front moves off the
Northeast and Mid-Atlantic Coast by Wednesday evening. The storm will
produce a significant winter storm impacting areas of the Great Lakes to
Northern New England. Periods of moderate to heavy snow will continue
today across Minnesota, Wisconsin, and Michigan. Additional snowfall may
exceed 6 inches, bringing event-total snowfall to 1-2 ft in some areas.
Moderate to heavy snow combined with strong winds gusting over 30 mph will
create near blizzard conditions at times with considerable blowing and
drifting snow. Travel is discouraged. Periods of sleet and freezing rain
will lift across Wisconsin and Michigan through Tuesday evening.
Significant ice accumulation exceeding †is possible, which will
create hazardous travel and isolated power outages. Very cold air is
expected for much of this week, with temperatures near record low values
and dangerously cold wind chills in the Plains. From Tuesday afternoon
into late Tuesday night, sleet and rain/freezing rain will develop over
parts of Northern New England. 

Moreover, temperatures will be 20 to 45 degrees below average over the
Northern Rockies/Northern High Plains into the Northern/Central Plains and
parts of the Upper Mississippi Valley. As a result, several locations will
have record-breaking or tied low temperatures. In contrast, temperatures
will be 10 to 25 degrees above average over most of the East Coast, with
several locations having record-breaking or tied high temperatures from
Tuesday into Wednesday morning. 

Meanwhile, as the cold front moves eastward over the Middle/Lower
Mississippi Valley into the Ohio/Tennessee Valleys, moisture will pool
along ahead of the boundary aiding in the development of showers and
thunderstorms; some thunderstorms will be severe. Therefore, the SPC has
issued a Slight Risk of severe thunderstorms over parts of the
Middle/Lower Mississippi and Ohio/Tennessee Valleys through Wednesday
morning. The hazards associated with these thunderstorms are frequent
lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. 

In addition, there is a threat of excessive rainfall associated with these
thunderstorms. Therefore, the WPC has issued a Moderate Risk of excessive
rainfall over parts of the Ohio Valley with a second over parts of the
Tennessee Valley. The associated heavy rain will create numerous areas of
flash flooding. Furthermore, many streams may flood, potentially affecting
larger rivers through Wednesday morning. 

However, the threat of severe thunderstorms will diminish on Wednesday
into Thursday over parts of the Middle/Lower Mississippi and
Ohio/Tennessee Valleys. Furthermore, heavy rain will continue as a strong
stream of moisture comes off the Gulf of Mexico and overruns the front
producing heavy rain over Lower Mississippi and Ohio/Tennessee Valleys.
Therefore, the WPC has issued a Slight Risk of excessive rainfall with the
heavy rain over parts of the Lower Mississippi and Tennessee Valleys. The
heavy rain will create mainly localized areas of flash flooding, with
urban areas, roads, and small streams the most vulnerable from Wednesday
into Thursday morning.

In the meantime, an upper-level low over the Pacific Northwest moves
southward to the Great Basin/Southern California by Wednesday morning,
then moves eastward to the Southern Rockies by Thursday. The system will
produce rain and higher elevation snow over parts of the Northwest and
Northern/Central California, with snow over parts of the Great Basin on
Tuesday. Snow will move into the Southwest and Central Rockies overnight
Tuesday into Wednesday morning. The snow and lower elevation rain will
continue over the Southwest and Central Rockies and expand into the
Southern Rockies and parts of the Central/Southern High Plains overnight
Wednesday into Thursday. 

Moreover, a second winter storm will develop as the system moves out of
the Southwest/Southern Rockies onto the Southern Plains. The storm will
develop over the Southern Plains on Wednesday, moving toward the Ohio
Valley on Thursday. Snow, sleet, and freezing rain are all likely.
Freezing rain and sleet are forecast to expand over the Southern Plains
and Middle Mississippi Valley starting Wednesday and continue into the
Ohio Valley Thursday. Significant ice accumulations are likely, with
damaging ice possible in the Ozarks. In addition, modest snowfall
accumulations are also possible. As a result, hazardous travel conditions
and impacts to infrastructure are becoming more likely. Details in the
track and timing of the storm and precipitation type and amounts remain
uncertain but will be refined in the next day or so.  

Ziegenfelder

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