Storm Summary Number 1 for Major Coast to Coast Winter Storm
NWS Weather Prediction Center College Park MD
900 PM CST Tue Feb 21 2023

...Moderate to heavy snow begins for portions of the Northern
Plains and Midwest...

Winter Storm Warnings and Advisories are in effect for much of the
Northern Plains, Intermountain West, and Upper Midwest.

Blizzard Warnings are in effect for portions of eastern South
Dakota, southeastern North Dakota, southwestern Minnesota, and
portions of northwestern Iowa.

Ice Storm Warnings will be in effect starting Wednesday morning
for a narrow region stretching from central Iowa eastward through
southern Michigan.

For a detailed graphical depiction of the latest watches, warnings
and advisories, please see www.weather.gov

At 800 PM CST...A deep upper-level trough is inducing a broad
region of low pressure across much of the western United States,
with a minimum pressure of 985 mb (29.09 in Hg) located over
eastern Colorado. There are currently multiple unorganized frontal
systems situated over the Plains and Intermountain West. First, a
warm front extended to the east of the low pressure through
regions of the Kansas and Oklahoma, ushering in very warm, moist
air into the central Plains. A cold front extends to the southwest
through New Mexico, under a noticeably cooler and drier airmass.
To the north, another set of frontal system extended from a
different low pressure center, located over northern Nebraska. A
strong cold front extended to the northwest of the low, traveling
through the Intermountain West, while a stationary front extended
to the east-southeast through portions of Nebraska and Missouri.
This front separated frigid, Arctic air to the north from a much
more moderate airmass to the south. Currently, National Weather
Service Radar and surface observations show a broad region of
moderate-heavy snow stretching from eastern Wyoming through
Minnesota and into western Michigan. In addition, some
orographically-induced precipitation is falling over regions of
the Intermountain West.

...Selected preliminary Storm Total Snowfall in inches from 700 AM
CST Fri Feb 21 through 800 PM CST Mon Jan 21...

...MINNESOTA...
COLERAINE 3 SSE                       4.2                    
VICTORIA                              3.0                    
DONNELLY 3 NW                         2.4                    
MSP AIRPORT                           1.1                    

...NORTH DAKOTA...
BISMARCK 3 SSE                        4.5                    
KILLDEER                              3.0                    
LIDGERWOOD                            3.0                    

...SOUTH DAKOTA...
LEAD                                  4.0                    
UTSA 8 NW                             3.0                    

...WYOMING...
WESTON 14 SW                          8.0                    


Snowfall currently falling over portions of the High Plains will
gradually diminish tonight as forcing weakens. By the conclusion
of the first round of snow, 4-8" of snow will have already fallen
across portions of the High Plains and Upper Midwest. As the
upper-level trough progresses eastward, lee cyclogenesis will act
to organize a surface low pressure system centered over eastern
Colorado and western Kansas tonight. This strong storm system will
move northeastward into the High Plains and Midwest by Wednesday,
where the second round of snow will begin. This storm system will
draw warm and very moist air northward, allowing for heavy snow
and high winds to set up across many of the same regions affected
by the first round of snow. Snow rates may exceed over 2" per hour
across a broad region of the High Plains on Wednesday. Storm-total
snowfall of 12-24" is expected stretching from South Dakota
through north-central Michigan. Locally higher snowfall amounts
are possible, especially across southern Minnesota. Heavy snow
accompanied by high winds may create prolonged blizzard conditions
across much of the High Plains. Travel conditions during the
duration of this event may be nearly impossible given the low
visibility and high snowfall rates. In the wake of this system,
frigid temperatures are expected for much of the High Plains, with
wind chills possibly reaching -20F for some spots. In addition to
the heavy snow and cold, there is growing potential for a
significant ice storm from central Iowa through regions of
southern Michigan. Ice accretions of 0.1"+ are possible across
this area, with locally higher amounts over Michigan.

The next Storm Summary will be issued by the Weather Prediction
Center at 900 AM CST. Please refer to your local National Weather
Service office for additional information on this event.

Genz