Blizzard and Winter Storm in South Dakota, April 23 to 24, 2022

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1120 PM MDT Fri Apr 22 2022

.DISCUSSION...(This Evening Through Friday)
Issued at 204 PM MDT Fri Apr 22 2022

Current surface map shows low over southeast Wyoming with warm
front/trof extending northward into western South Dakota...just
east of the Black Hills. With surface dewpoints in the
50s...MLCAPE is >2000J/KG just east of the boundary. Strong
shear/straight line hodographs favorable for large hail. HREF
shows potential for some longer lived updrafts tracking through
the Black Hills into northwest South Dakota. West of the
boundary, storms should remain elevated...with the main threat
being large hail. There is a small window of opportunity for
tornado development east of the boundary where storms could
become surface based...through large DCAPE/higher LCL would favor
outflow dominated storms/damaging winds to go along with the hail
threat. Severe thunderstorm coverage diminishes this
evening...with some lingering potential across south central South
Dakota along cold front/dryline.

Attention turns to cold side of storm system tonight/Saturday.
Negative tilted shortwave closes off just east of the Black Hills
Saturday morning, then slowly lifts into south central North
Dakota. Robust lift sets up across northeast Wyoming/far western
South Dakota with mature TROWAL/deformation zone. Steep mid level
lapse rates/deep lift in DGZ will favor 1-2" per hour snowfall
rates. Upslope flow with with favorable buoyancy from BL-6000ft
AGL could push snowfall rates as high as 3" per hour for the
northern Black Hills. Gradient/momentum transfer will result in
widespread wind gusts over 60 mph. Dangerous blizzard conditions
with axis of heavy snow with power outages/tree damage possible.
Made some minor changes to timing of blizzard warning...mainly for
slower rain/snow transition across far northwest South Dakota.
Biggest issue was what to do with transition area east of the
Blizzard Warning. For areas east/northeast of the Rapid City,
some light snow will spread across the area Saturday afternoon
into Saturday night. While snowfall snowfall amounts will
generally be an inch or two, some upslope enhancement is possible
on the higher ridges. With the strong winds, opted to issue winter
weather advisory to account for the poor visibility/difficult
travel conditions. For Rapid City itself, once the surface/mid
level low gets north of I-90, it will be a battle between large
scale forcing and downslope flow. Have trimmed back QPF/snowfall
amounts for Rapid City and areas along highway 79 south of Rapid
City and opted for High Wind Warning...with High Wind Warning into
southwest South Dakota. Didn't make any changes to end time of
Blizzard/Winter Storm warnings at this time. Some snow should
linger into Sunday morning, especially in upslope favorable areas.
Will also remain breezing Sunday with some patchy blowing snow.

Upper Ridge builds across the area early next week with
temperatures warming back up. Coolest areas will be over deeper
snow cover. Active pattern returns for the end of the week with a
chance of rain/thunderstorms.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Saturday Night)
Issued At 1119 PM MDT Fri Apr 22 2022

Showers/thunderstorms will move northeast overnight with areas
IFR conditions at times. A strong storm system will wrap up
overnight into Saturday bringing widespread IFR/local LIFR
conditions due to rain/snow/blowing snow/low CIGS. Strong wind
gusts from 35-60kt are likely over much of the area through
Saturday.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Warning until 6 AM MDT Sunday for SDZ024-028.

     High Wind Warning from noon Saturday to 6 AM MDT Sunday for
     SDZ026-027-030-032-041>044-074.

     High Wind Warning until 5 AM CDT early this morning for SDZ046-
     047-049.

     Blizzard Warning from 6 AM Saturday to 6 AM MDT Sunday for
     SDZ001-002-012-025-072.

     Winter Weather Advisory from noon Saturday to 6 AM MDT Sunday
     for SDZ013-014-031-073.

     Winter Weather Advisory until 6 AM MDT Sunday for SDZ029.

WY...Winter Storm Warning until 6 AM MDT Sunday for WYZ057.

     Blizzard Warning until 6 AM MDT Sunday for WYZ054>056-058-071.

&&

DISCUSSION...7
AVIATION...Helgeson

Hazardous Weather Outlook
National Weather Service Rapid City SD
413 AM MDT Fri Apr 22 2022

SDZ001-002-012-025-072-WYZ054>056-058-071-231300-
Harding-Perkins-Butte-Northern Foot Hills-
Sturgis/Piedmont Foot Hills-Northern Campbell-Southern Campbell-
Western Crook-Weston-Northeastern Crook-
413 AM MDT Fri Apr 22 2022

This Hazardous Weather Outlook is for portions of northwestern
South Dakota...and northeast Wyoming.

.DAY ONE...Today and Tonight

Rain and a few thunderstorms will develop this afternoon and
continue into this evening. Severe thunderstorms are possible over
and near the Black Hills and northwestern South Dakota. Rain will
change to snow overnight. A Blizzard Warning is in effect starting
at midnight tonight.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The Blizzard Warning will continue until 6AM on Sunday morning.
Heavy snow and strong and gusty northwest winds will occur on
Saturday with hazardous travel conditions due to falling, blowing
and drifting snow.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

SDZ013-014-026-027-030>032-041>044-073-074-231300-
Northern Meade Co Plains-Ziebach-Rapid City-Southern Foot Hills-
Custer Co Plains-Pennington Co Plains-Haakon-Fall River-
Oglala Lakota-Jackson-Bennett-Southern Meade Co Plains-
Hermosa Foot Hills-
413 AM MDT Fri Apr 22 2022

This Hazardous Weather Outlook is for portions of northwestern
South Dakota...and southwestern South Dakota.

.DAY ONE...Today and Tonight

Scattered showers and thunderstorms will develop this afternoon
and evening. Severe thunderstorms are possible, with large hail
and damaging wind gusts.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Strong and gusty northwest winds will occur on Saturday with wind
gusts of 60 to 70 mph possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

SDZ046-047-049-231300-
Mellette-Todd-Tripp-
513 AM CDT Fri Apr 22 2022

This Hazardous Weather Outlook is for portions of south central
South Dakota.

.DAY ONE...Today and Tonight

Very windy conditions will develop this afternoon with southerly
gusts up to 55 mph possible. A Wind Advisory has been issued.
Showers and thunderstorms will develop during the late afternoon
and early evening hours. Severe thunderstorms are possible, with
large hail and damaging wind gusts. A tornado is also possible.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Strong and gusty northwest winds will develop on Saturday with
gusts up to 65 mph possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

SDZ024-028-WYZ057-231300-
Northern Black Hills-Central Black Hills-Wyoming Black Hills-
413 AM MDT Fri Apr 22 2022

This Hazardous Weather Outlook is for portions of the Black Hills
of South Dakota...and the Black Hills of Wyoming.

.DAY ONE...Today and Tonight

Rain and a few thunderstorms will develop this afternoon and
continue into this evening. Severe thunderstorms are possible with
large hail and damaging wind gusts. Rain will change to snow
overnight. A Winter Storm Warning is in effect starting at
midnight tonight.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The Winter Storm Warning will continue until Sunday morning. Heavy
snow is expected, along with widespread blowing and drifting snow.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

SDZ029-231300-
Southern Black Hills-
413 AM MDT Fri Apr 22 2022

This Hazardous Weather Outlook is for portions of the Black Hills
of South Dakota.

.DAY ONE...Today and Tonight

Rain and a few thunderstorms will develop this afternoon and
continue into this evening. Severe thunderstorms are possible with
large hail and damaging wind gusts. Rain will change to snow
overnight. A Winter Weather Advisory is in effect starting at
midnight tonight.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

The Winter Weather Advisory will continue until Sunday morning.
Snow and blowing snow will create hazardous travel conditions.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today.

&&

Stay tuned to NOAA weather radio for further updates...or check
our web site at weather.gov/rapidcity

Special Weather Statement
National Weather Service Rapid City SD
1043 PM MDT Fri Apr 22 2022

SDZ024-026-028-031-072-073-230515-
Northern Black Hills SD-Pennington Co Plains SD-
Central Black Hills SD-Southern Meade Co Plains SD-
Sturgis/Piedmont Foot Hills SD-Rapid City SD-
1043 PM MDT Fri Apr 22 2022

...Strong thunderstorms will impact portions of southwestern Meade
and central Pennington Counties through 1115 PM MDT...

At 1043 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Black Hawk to 5 miles northeast of
Railroad Buttes. Movement was northeast at 30 mph.

HAZARD...Wind gusts of 50 to 55 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Strong thunderstorms will be near...
  New Underwood around 1100 PM MDT.

Other locations in the path of these storms include Owanka and
Wicksville.

This includes Interstate 90 in South Dakota between Mile Markers 45
and 94.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until midnight MDT for
west central South Dakota.

&&

LAT...LON 4439 10328 4412 10247 4387 10274 4413 10348
TIME...MOT...LOC 0443Z 214DEG 26KT 4415 10335 4395 10279

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...55 MPH

Trimarchi

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RAPID CITY SD
1047 PM MDT FRI APR 22 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1011 PM     TSTM WND GST     3 ESE PINE RIDGE        43.03N 102.52W
04/22/2022  M62 MPH          OGLALA LAKOTA      SD   ASOS

1013 PM     TSTM WND GST     RAPID CITY ARPT         44.05N 103.05W
04/22/2022  M60 MPH          PENNINGTON         SD   ASOS

1025 PM     TSTM WND GST     3 NW WASTA              44.10N 102.50W
04/22/2022  M54 MPH          PENNINGTON         SD   MESONET

1028 PM     NON-TSTM WND GST 6 W PARMELEE            43.32N 101.15W
04/22/2022  M50 MPH          TODD               SD   MESONET

1030 PM     NON-TSTM WND GST 11 SW PARMELEE          43.23N 101.20W
04/22/2022  M57 MPH          TODD               SD   MESONET

1031 PM     TSTM WND GST     5 WNW NEW UNDERWOOD     44.12N 102.93W
04/22/2022  M55 MPH          PENNINGTON         SD   MESONET

1031 PM     NON-TSTM WND GST 15 SSE MISSION          43.10N 100.60W
04/22/2022  M55 MPH          TODD               SD   MESONET

1031 PM     NON-TSTM WND GST 4 SSE WITTEN            43.39N 100.07W
04/22/2022  M54 MPH          TRIPP              SD   MESONET

1031 PM     NON-TSTM WND GST WEWELA                  43.01N  99.78W
04/22/2022  M59 MPH          TRIPP              SD   MESONET

1033 PM     TSTM WND GST     1 W BOX ELDER           44.12N 103.09W
04/22/2022  M50 MPH          PENNINGTON         SD   MESONET

&&

WFO UNR

Special Weather Statement
National Weather Service Rapid City SD
1103 PM MDT Fri Apr 22 2022

SDZ002-013-014-032-230600-
Perkins SD-Ziebach SD-Haakon SD-Northern Meade Co Plains SD-
1103 PM MDT Fri Apr 22 2022

...Strong thunderstorms will impact portions of northwestern Haakon,
Ziebach, northeastern Meade and southeastern Perkins Counties through
MIDNIGHT MDT...

At 1103 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles northeast of Maurine to 6 miles
northwest of Red Scaffold to 2 miles east of Billsburg. Movement was
northeast at 45 mph.

HAZARD...Wind gusts of 50 to 55 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Dupree, Faith, Cherry Creek, Milesville, Meadow, Chance, Maurine,
Usta, Glad Valley, South Eagle Butte, Red Scaffold, Billsburg,
Thunder Butte, Red Elm, Iron Lightning, Takini, Durkee Lake and
Arrow Head Buttes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until midnight MDT for
west central South Dakota.

&&

LAT...LON 4562 10199 4547 10199 4548 10163 4541 10146
      4500 10150 4499 10121 4485 10113 4475 10113
      4424 10170 4477 10198 4503 10264 4568 10216
TIME...MOT...LOC 0503Z 211DEG 39KT 4510 10244 4484 10192 4439 10163

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH

Trimarchi

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