Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Mon Feb 21 2022

Valid 12Z Mon Feb 21 2022 - 12Z Wed Feb 23 2022

...Significant winter storm impacting areas of the Plains into the Great
Lakes on Monday into Tuesday...

...Risk of Excessive rainfall, Critical fire weather and severe
thunderstorms increasing from the Southern Plains to Tennessee/Ohio
Valleys from Monday into Wednesday...

...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 developing wave of low pressure over the Central Plains will move
northeastward to the Great Lakes by Tuesday evening and into Quebec,
Canada, by Wednesday morning. The storm will produce a significant winter
storm impacting areas of the Plains into the Great Lakes. A mixture of
snow, sleet, and freezing rain may come in two waves to parts of the
region. Snow will become heavy, with snowfall rates of one inch per hour
or higher with the significant and long-duration winter storm. Increasing
wind may lead to significant blowing and drifting of snow. Near blizzard
conditions are possible over parts of North and South Dakota. Travel is
discouraged. Total snowfall amounts will likely exceed 6 inches from the
Dakotas into the Upper Great Lakes. More than 12 inches are possible in
some areas over the two days. Significant ice accumulations are possible
into the Upper Midwest and Great Lakes starting Monday evening into
Tuesday. Some areas may receive a quarter-inch of ice. Very cold air is
expected for much of this week, with temperatures near record low values
and dangerously cold wind chills in the Plains.

Moreover, temperatures will be 20 to 30 degrees below average over the
Northern Tier States, with several locations having record-breaking or
tied low temperatures. In contrast, temperatures will be 10 to 25 degrees
above average over Lower/Middle Mississippi Valley into the Ohio Valley
from Monday into Wednesday morning.

Meanwhile, as the cold front moves southward over the Central/Southern
Plains and the Middle/Lower Mississippi Valley, 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 Southern Plains
and Middle/Lower Mississippi/Tennessee Valleys through Tuesday 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 Slight Risk of excessive
rainfall with these thunderstorms. The associated heavy rain will create
mainly localized areas of flash flooding, with urban areas, roads, and
small streams the most vulnerable through Tuesday morning.

However, the threat of severe thunderstorms will move eastward as the
front pushes through the Lower Mississippi/Tennessee Valleys. Therefore,
from Tuesday into Wednesday morning, the SPC has issued a Slight Risk of
severe thunderstorms over parts of the Middle/Lower Mississippi and
Tennessee Valleys. The hazards associated with these thunderstorms are
frequent lightning, severe thunderstorm wind gusts, hail, and a few
tornadoes. Furthermore, heavy rain will also be associated with these
thunderstorms as a strong stream of moisture comes off the Gulf of Mexico.
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
from Tuesday into Wednesday morning.

In the meantime, with the warm temperatures, dry fuels, and gusty wind
over the Southern High Plains, the SPC has issued a Critical Risk of fire
weather over the region on Monday that will reduce to an Elevated Risk on
Tuesday. Elsewhere, coastal rain and higher elevation snow will end over
the Pacific Northwest by late morning on Tuesday. Upper-level energy and a
surface front will move into California and the Southwest on Tuesday into
Wednesday. Rain and higher elevation snow will start over California late
Monday morning and expand into Southern California by Tuesday afternoon.
Snow will move into the Great Basin and the Southwest into the Central
Rockies overnight Tuesday into Wednesday morning.


Ziegenfelder


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