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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

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