Alert archive / South Dakota / Winter Storm Warnings in 2021

Winter Storm Warning 10, NWS Rapid City, SD

December 9, 20219 counties in South Dakota; Weston County, Wyoming

NWS Rapid City, SD issued this winter storm warning at Dec 9, 2021, 2:10 AM MST for 9 counties in South Dakota; Weston County, Wyoming. It took effect at Dec 9, 2021, 8:00 PM MST. It was in force for 21 hr. 60 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Dec 9, 2021, 2:10 AM MST (09:10 UTC)
In effect from
Dec 9, 2021, 8:00 PM MST
Expired
Dec 10, 2021, 5:00 PM MST
In force
21 hr
Issued by
NWS Rapid City, SD

Counties Bennett County, SD, Custer County, SD, Fall River County, SD, Jackson County, SD, Mellette County, SD, Oglala Lakota County, SD, Pennington County, SD, Todd County, SD, Tripp County, SD, Weston County, WY

The radar

The Rapid City radar (KUDX), 87 km from the middle of the area, began a volume at 09:14 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Dec 10, 4:32 AM MSTHEAVY SNOW 13Hot Springs, SD
Dec 10, 5:00 AM MSTSNOW 4.11 E Dwtn Rapid City, SDSTORM TOTAL SO FAR...STILL SNOWING
Dec 10, 5:00 AM MSTSNOW 54 Nnw Fairburn, SD24-HOUR SNOWFALL.
Dec 10, 5:00 AM MSTHEAVY SNOW 610 Ese Hermosa, SD24-HOUR SNOWFALL.
Dec 10, 5:10 AM MSTSNOW 1.72 E Cottonwood, SDSTORM TOTAL SO FAR
Dec 10, 5:10 AM MSTSNOW 3.91 Wnw Caputa, SDSTORM TOTAL SO FAR
Dec 10, 5:29 AM MSTHEAVY SNOW 64 Ssw Hill City, SD24-HOUR SNOWFALL.
Dec 10, 5:33 AM MSTHEAVY SNOW 6.5Hill City, SDTOTAL SO FAR
Dec 10, 5:52 AM MSTSNOW 45 Wnw Rapid City Arpt, SDTOTAL SO FAR
Dec 10, 5:53 AM MSTHEAVY SNOW 14Hot Springs, SDTOTAL SO FAR
Dec 10, 6:00 AM MSTSNOW 34 Nw Dwtn Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 6:00 AM MSTSNOW 59 Ene Wewela, SD24-HOUR SNOWFALL.
Dec 10, 6:00 AM MSTSNOW 5.713 Ene White River, SD24-HOUR SNOWFALL.
Dec 10, 6:00 AM MSTHEAVY SNOW 617 Nw White River, SD24-HOUR SNOWFALL.
Dec 10, 6:00 AM MSTHEAVY SNOW 67 Sw Rapid City Arpt, SD
Dec 10, 6:00 AM MSTHEAVY SNOW 74 E Newcastle, WY24-HOUR SNOWFALL.
Dec 10, 6:00 AM MSTHEAVY SNOW 7.5Hill City, SD24-HOUR SNOWFALL.
Dec 10, 6:00 AM MSTHEAVY SNOW 105 Se Olsonville, SD24-HOUR SNOWFALL.
Dec 10, 6:00 AM MSTHEAVY SNOW 18Oral, SD24-HOUR SNOWFALL.
Dec 10, 6:05 AM MSTHEAVY SNOW 88 Nne Jewel Cave, SD
Dec 10, 6:06 AM MSTSNOW 42 W Dwtn Rapid City, SD
Dec 10, 6:07 AM MSTSNOW 4Johnson Siding, SD
Dec 10, 6:09 AM MSTHEAVY SNOW 8Mission, SD
Dec 10, 6:11 AM MSTHEAVY SNOW 6.64 Ne Rockerville, SD
Dec 10, 6:15 AM MSTHEAVY SNOW 1511 W Hot Springs, SD
Dec 10, 6:20 AM MSTHEAVY SNOW 7.45 Nne Rockerville, SD
Dec 10, 6:21 AM MSTHEAVY SNOW 142 E Oral, SD
Dec 10, 6:36 AM MSTHEAVY SNOW 10Long Valley, SD
Dec 10, 6:40 AM MSTSNOW 4.71 Wnw Caputa, SDUPDATED SNOW TOTAL
Dec 10, 6:40 AM MSTSNOW 5.54 Sw Dwtn Rapid City, SD
Dec 10, 6:43 AM MSTSNOW 3.32 E Cottonwood, SDUPDATED SNOW TOTAL
Dec 10, 7:00 AM MSTSNOW 2.526 Wsw Newcastle, WY24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTSNOW 4.33 Wnw Kadoka, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTSNOW 4.410 Wnw Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTSNOW 4.52 Nw Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTSNOW 4.57 W Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTSNOW 55 E Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTSNOW 5.38 W Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTSNOW 5.515 Sse Belvidere, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTHEAVY SNOW 63 Wnw Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTHEAVY SNOW 6.54 S Rapid City, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTHEAVY SNOW 7.56 W Hermosa, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTHEAVY SNOW 91 W Newcastle, WY24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTHEAVY SNOW 92 Ene Edgemont, SD24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTHEAVY SNOW 108 N Newcastle, WY24-HOUR SNOWFALL.
Dec 10, 7:00 AM MSTHEAVY SNOW 17Hot Springs, SD24-HOUR SNOWFALL.
Dec 10, 7:15 AM MSTSNOW 5Box Elder, SD24-HOUR SNOWFALL.
Dec 10, 7:20 AM MSTSNOW 53 S Dwtn Rapid City, SD
Dec 10, 7:21 AM MSTHEAVY SNOW 135 W Hot Springs, SD
Dec 10, 7:22 AM MSTHEAVY SNOW 16Hot Springs, SD
Dec 10, 7:23 AM MSTHEAVY SNOW 7Custer, SD
Dec 10, 7:29 AM MSTHEAVY SNOW 7.55 Ene Custer, SD
Dec 10, 7:30 AM MSTHEAVY SNOW 9.51 S Rockerville, SD
Dec 10, 7:32 AM MSTHEAVY SNOW 98 Se Interior, SD
Dec 10, 7:40 AM MSTHEAVY SNOW 9Interior, SD
Dec 10, 7:45 AM MSTHEAVY SNOW 85 N Newcastle, WY24-HOUR SNOWFALL.
Dec 10, 7:45 AM MSTHEAVY SNOW 14Smithwick, SD
Dec 10, 7:48 AM MSTHEAVY SNOW 81 W Newcastle, WY
Dec 10, 7:51 AM MSTHEAVY SNOW 9.5Martin, SD
Dec 10, 7:53 AM MSTHEAVY SNOW 84 Se Keystone, SD

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 9.2 hours before the alert went out and 85 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Rapid City, SD at 00:00Z on 2021-12-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 00:00Z on 2021-12-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2445 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
117 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

689 
WWUS43 KUNR 090910
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
210 AM MST Thu Dec 9 2021

SDZ027-029-030-041-042-044-074-100000-
/O.UPG.KUNR.WS.A.0008.211210T0100Z-211210T1900Z/
/O.NEW.KUNR.WS.W.0010.211210T0300Z-211210T2100Z/
Southern Foot Hills-Southern Black Hills-Custer Co Plains-
Fall River-Oglala Lakota-Bennett-Hermosa Foot Hills-
Including Edgemont, Hot Springs, Custer, Jewel Cave, Pringle, 
Custer State Park, Wind Cave, Folsom, Ardmore, Pine Ridge, 
Oglala, Kyle, Martin, Hermosa, Buffalo Gap, and Fairburn
210 AM MST Thu Dec 9 2021

...WINTER STORM WARNING IN EFFECT FROM 8 PM THIS EVENING TO 2 PM
MST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 9
  inches, with the highest amounts near the Nebraska border.

* WHERE...Portions of southwestern South Dakota. This includes 
  the Tribal Lands of the Pine Ridge Reservation.

* WHEN...From 8 PM this evening to 2 PM MST Friday.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ043-100000-
/O.UPG.KUNR.WS.A.0008.211210T0600Z-211211T0000Z/
/O.NEW.KUNR.WS.W.0010.211210T0300Z-211210T2100Z/
Jackson-
Including Kadoka
210 AM MST Thu Dec 9 2021

...WINTER STORM WARNING IN EFFECT FROM 8 PM THIS EVENING TO 2 PM
MST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations ranging
  from 2 inches in the northern part of the county, to around 6 
  inches in the south.

* WHERE...Jackson County. This includes the Tribal Lands of the 
  Pine Ridge Reservation.

* WHEN...From 8 PM this evening to 2 PM MST Friday.

* IMPACTS...Travel could be very difficult.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ046-047-049-100000-
/O.UPG.KUNR.WS.A.0008.211210T0600Z-211211T0000Z/
/O.NEW.KUNR.WS.W.0010.211210T0600Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
310 AM CST Thu Dec 9 2021

...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 PM
CST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 7
  inches, with the highest amounts near the Nebraska border. Winds
  gusting as high as 35 mph Friday afternoon.

* WHERE...Mellette County, Todd County and Tripp County. This 
  includes the Tribal Lands of the Rosebud Reservation.

* WHEN...From midnight tonight to 6 PM CST Friday.

* IMPACTS...Travel could be very difficult.

* ADDITIONAL DETAILS...Patchy blowing snow will be possible Friday
  afternoon as northwest winds increase.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ026-028-031-WYZ055-058-100000-
/O.NEW.KUNR.WW.Y.0013.211210T0300Z-211210T1800Z/
Rapid City-Central Black Hills-Pennington Co Plains-
Southern Campbell-Weston-
Including Rapid City, Hill City, Mt Rushmore, Deerfield, Hisega, 
Mystic, Pactola Reservoir, Rochford, Rockerville, Box Elder, 
Caputa, Wall, Wright, and Upton
210 AM MST Thu Dec 9 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO
11 AM MST FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 
  inches.

* WHERE...In Wyoming, Southern Campbell County and the Weston 
  County Plains. In South Dakota, the Rapid City area, the 
  Central Black Hills and the Pennington County Plains.

* WHEN...From 8 PM this evening to 11 AM MST Friday.

* IMPACTS...Plan on slippery road conditions.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$
7 follow-up statements
766 
WWUS43 KUNR 092002
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
102 PM MST Thu Dec 9 2021


SDZ027-029-030-041>044-074-101115-
/O.CON.KUNR.WS.W.0010.211210T0300Z-211210T2100Z/
Southern Foot Hills-Southern Black Hills-Custer Co Plains-
Fall River-Oglala Lakota-Jackson-Bennett-Hermosa Foot Hills-
Including Edgemont, Hot Springs, Custer, Jewel Cave, Pringle, 
Custer State Park, Wind Cave, Folsom, Ardmore, Pine Ridge, 
Oglala, Kyle, Kadoka, Martin, Hermosa, Buffalo Gap, and Fairburn
102 PM MST Thu Dec 9 2021

...WINTER STORM WARNING REMAINS IN EFFECT FROM 8 PM THIS EVENING
TO 2 PM MST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 
  11 inches.

* WHERE...Portions of southwestern and the Black Hills of South 
  Dakota. This includes the Tribal Lands of the Pine Ridge 
  Reservation.

* WHEN...From 8 PM this evening to 2 PM MST Friday.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ046-047-049-101115-
/O.CON.KUNR.WS.W.0010.211210T0600Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
202 PM CST Thu Dec 9 2021

...WINTER STORM WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT
TO 6 PM CST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 6 to 9 
  inches.

* WHERE...Todd County, Mellette County and Tripp County. This 
  includes the Tribal Lands of the Rosebud Reservation.

* WHEN...From midnight tonight to 6 PM CST Friday.

* IMPACTS...Travel could be very difficult. Patchy blowing snow 
  could significantly reduce visibility.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ024-072-WYZ057-101115-
/O.EXA.KUNR.WW.Y.0013.211210T0300Z-211210T1800Z/
Northern Black Hills-Sturgis/Piedmont Foot Hills-
Wyoming Black Hills-
Including Lead, Deadwood, Brownsville, Cheyenne Crossing, Galena,
Nemo, Sturgis, Piedmont, Summerset, Sundance, Aladdin, Beulah, 
and Four Corners
102 PM MST Thu Dec 9 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO
11 AM MST FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 1 to 4 
  inches.

* WHERE...In Wyoming, the Wyoming Black Hills. In South Dakota, 
  the Northern Black Hills and the Sturgis/Piedmont Foot Hills.

* WHEN...From 8 PM this evening to 11 AM MST Friday.

* IMPACTS...Plan on slippery road conditions.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ026-028-031-WYZ055-058-101115-
/O.CON.KUNR.WW.Y.0013.211210T0300Z-211210T1800Z/
Rapid City-Central Black Hills-Pennington Co Plains-
Southern Campbell-Weston-
Including Rapid City, Hill City, Mt Rushmore, Deerfield, Hisega, 
Mystic, Pactola Reservoir, Rochford, Rockerville, Box Elder, 
Caputa, Wall, Wright, and Upton
102 PM MST Thu Dec 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 8 PM THIS
EVENING TO 11 AM MST FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 7 
  inches.

* WHERE...In South Dakota, the Rapid City area, the Central 
  Black Hills and the Pennington County Plains. In Wyoming, the 
  Weston County Plains and Southern Campbell County.

* WHEN...From 8 PM this evening to 11 AM MST Friday.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$
046 
WWUS43 KUNR 100158
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
658 PM MST Thu Dec 9 2021

...HEAVY SNOW TONIGHT INTO FRIDAY...

.A quick moving storm system will track east-northeast across
the region tonight and Friday, bringing snow to much of northeast
Wyoming, the Black Hills, and southern South Dakota. The heaviest
snow will generally track across the southern Black Hills, as well
as far southwest into far south central South Dakota, overnight 
and Friday morning, where 6 to 12 inches of accumulation is 
expected in many areas. Snowfall amounts of 2 to 6 inches are 
expected across southern portions of northeast Wyoming, the 
northern Black Hills, and much of the west central South Dakota 
plains. Amounts will drop off quickly across far northeast Wyoming
and northwest South Dakota, where little or no snowfall is 
expected. Snow will taper off from west to east across the area on
Friday. 

SDZ028-101700-
/O.UPG.KUNR.WW.Y.0013.211210T0300Z-211210T1800Z/
/O.EXA.KUNR.WS.W.0010.211210T0300Z-211210T2100Z/
Central Black Hills-
Including Hill City, Mt Rushmore, Deerfield, Hisega, Mystic, 
Pactola Reservoir, Rochford, and Rockerville
658 PM MST Thu Dec 9 2021

...WINTER STORM WARNING IN EFFECT UNTIL 2 PM MST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 5 to 9 
  inches.

* WHERE...The Central Black Hills.

* WHEN...Until 2 PM MST Friday.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ027-029-030-041>044-074-101700-
/O.CON.KUNR.WS.W.0010.211210T0300Z-211210T2100Z/
Southern Foot Hills-Southern Black Hills-Custer Co Plains-
Fall River-Oglala Lakota-Jackson-Bennett-Hermosa Foot Hills-
Including Edgemont, Hot Springs, Custer, Jewel Cave, Pringle, 
Custer State Park, Wind Cave, Folsom, Ardmore, Pine Ridge, 
Oglala, Kyle, Kadoka, Martin, Hermosa, Buffalo Gap, and Fairburn
658 PM MST Thu Dec 9 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 PM MST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 5 to 12
  inches, highest amounts generally near the Nebraska border.

* WHERE...Portions of southwestern and the Black Hills of South 
  Dakota. This includes the Tribal Lands of the Pine Ridge 
  Reservation.

* WHEN...Until 2 PM MST Friday.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ046-047-049-101700-
/O.CON.KUNR.WS.W.0010.211210T0600Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
758 PM CST Thu Dec 9 2021

...WINTER STORM WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT
TO 6 PM CST FRIDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 5 to 10
  inches.

* WHERE...Todd County, Mellette County and Tripp County. This 
  includes the Tribal Lands of the Rosebud Reservation.

* WHEN...From midnight tonight to 6 PM CST Friday.

* IMPACTS...Travel could be very difficult. Patchy blowing snow 
  could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ026-031-WYZ055-058-101700-
/O.CON.KUNR.WW.Y.0013.211210T0300Z-211210T1800Z/
Rapid City-Pennington Co Plains-Southern Campbell-Weston-
Including Rapid City, Box Elder, Caputa, Wall, Wright, and Upton
658 PM MST Thu Dec 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST
FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 6 inches.
  Locally higher amounts possible across far southern Campbell and
  Weston counties in Wyoming. 

* WHERE...In South Dakota, the Rapid City area and the 
  Pennington County Plains. In Wyoming, the Weston County Plains 
  and Southern Campbell County.

* WHEN...Until 11 AM MST Friday.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ024-072-WYZ057-101700-
/O.CON.KUNR.WW.Y.0013.211210T0300Z-211210T1800Z/
Northern Black Hills-Sturgis/Piedmont Foot Hills-
Wyoming Black Hills-
Including Lead, Deadwood, Brownsville, Cheyenne Crossing, Galena,
Nemo, Sturgis, Piedmont, Summerset, Sundance, Aladdin, Beulah, 
and Four Corners
658 PM MST Thu Dec 9 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST
FRIDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 5 inches,
  highest amounts generally over the higher elevations. 

* WHERE...In South Dakota, the Sturgis/Piedmont Foot Hills and 
  the Northern Black Hills. In Wyoming, the Wyoming Black Hills.

* WHEN...Until 11 AM MST Friday.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$
180 
WWUS43 KUNR 100759
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
1259 AM MST Fri Dec 10 2021

WYZ058-101800-
/O.UPG.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
/O.EXB.KUNR.WS.W.0010.000000T0000Z-211210T1800Z/
Weston-
Including Upton
1259 AM MST Fri Dec 10 2021

...WINTER STORM WARNING IN EFFECT UNTIL 11 AM MST THIS MORNING...

* WHAT...Heavy snow. Total snow accumulations of 4 to 8 inches.

* WHERE...The Weston County Plains.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ026-031-102100-
/O.UPG.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
/O.EXA.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Rapid City-Pennington Co Plains-
Including Rapid City, Box Elder, Caputa, and Wall
1259 AM MST Fri Dec 10 2021

...WINTER STORM WARNING IN EFFECT UNTIL 2 PM MST THIS AFTERNOON...

* WHAT...Heavy snow. Total snow accumulations of 4 to 8 inches. 
  The highest amounts will be along and south of Highway 44.

* WHERE...The Rapid City area and the Pennington County Plains.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ027>030-041>044-074-102100-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Fall River-Oglala Lakota-Jackson-Bennett-
Hermosa Foot Hills-
Including Edgemont, Hot Springs, Hill City, Mt Rushmore, 
Deerfield, Hisega, Mystic, Pactola Reservoir, Rochford, 
Rockerville, Custer, Jewel Cave, Pringle, Custer State Park, 
Wind Cave, Folsom, Ardmore, Pine Ridge, Oglala, Kyle, Kadoka, 
Martin, Hermosa, Buffalo Gap, and Fairburn
1259 AM MST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Heavy snow. Total snow accumulations of 6 to 12 inches,
  with the highest amounts along Highway 18.

* WHERE...Portions of southwestern and the Black Hills of South 
  Dakota. This includes the Tribal Lands of the Pine Ridge 
  Reservation.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Travel could be very difficult.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ046-047-049-102300-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
159 AM CST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...

* WHAT...Heavy snow. Total snow accumulations of 6 to 12 inches.

* WHERE...Todd County, Mellette County and Tripp County. This 
  includes the Tribal Lands of the Rosebud Reservation.

* WHEN...Until 6 PM CST this evening.

* IMPACTS...Travel could be very difficult. Patchy blowing snow 
  could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ032-073-102100-
/O.EXB.KUNR.WW.Y.0013.000000T0000Z-211210T2100Z/
Haakon-Southern Meade Co Plains-
Including Philip and Ellsworth AFB
1259 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Snow. Total snow accumulations of 1 to 4 inches, with the
  highest amounts along Highway 14.

* WHERE...Haakon County and the Southern Meade County Plains.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ025-101800-
/O.EXA.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
Northern Foot Hills-
Including Spearfish and Whitewood
1259 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 AM MST THIS
MORNING...

* WHAT...Snow. Total snow accumulations of 1 to 3 inches.

* WHERE...The Northern Foot Hills.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

WYZ055-101800-
/O.CON.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
Southern Campbell-
Including Wright
1259 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST THIS
MORNING...

* WHAT...Snow. Total snow accumulations of 3 to 6 inches, with the
  highest amounts along and south of Highway 387.

* WHERE...Southern Campbell County.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ024-072-WYZ057-101800-
/O.CON.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
Northern Black Hills-Sturgis/Piedmont Foot Hills-
Wyoming Black Hills-
Including Lead, Deadwood, Brownsville, Cheyenne Crossing, Galena,
Nemo, Sturgis, Piedmont, Summerset, Sundance, Aladdin, Beulah, 
and Four Corners
1259 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST THIS
MORNING...

* WHAT...Snow. Total snow accumulations of 2 to 5 inches.

* WHERE...In South Dakota, the Sturgis/Piedmont Foot Hills and 
  the Northern Black Hills. In Wyoming, the Wyoming Black Hills.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$
246 
WWUS43 KUNR 101251
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
551 AM MST Fri Dec 10 2021

SDZ027>030-041>044-074-102100-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Fall River-Oglala Lakota-Jackson-Bennett-
Hermosa Foot Hills-
Including Edgemont, Hot Springs, Hill City, Mt Rushmore, 
Deerfield, Hisega, Mystic, Pactola Reservoir, Rochford, 
Rockerville, Custer, Jewel Cave, Pringle, Custer State Park, 
Wind Cave, Folsom, Ardmore, Pine Ridge, Oglala, Kyle, Kadoka, 
Martin, Hermosa, Buffalo Gap, and Fairburn
551 AM MST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Heavy snow. Additional snow accumulations of 1 to 3 
  inches.

* WHERE...Portions of southwestern South Dakota. This includes 
  the Tribal Lands of the Pine Ridge Reservation.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ046-047-049-110000-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
651 AM CST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...

* WHAT...Heavy snow. Additional snow accumulations of 3 to 5 
  inches.

* WHERE...Todd County, Mellette County and Tripp County. This 
  includes the Tribal Lands of the Rosebud Reservation.

* WHEN...Until 6 PM CST this evening.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ026-031-102100-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Rapid City-Pennington Co Plains-
Including Rapid City, Box Elder, Caputa, and Wall
551 AM MST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Heavy snow. Additional snow accumulations of up to two 
  inches.

* WHERE...The Pennington County Plains and the Rapid City area.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

WYZ058-101800-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211210T1800Z/
Weston-
Including Upton
551 AM MST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 11 AM MST THIS
MORNING...

* WHAT...Heavy snow. Additional snow accumulations of 1 to 2 
  inches.

* WHERE...The Weston County Plains.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

WYZ055-101800-
/O.CON.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
Southern Campbell-
Including Wright
551 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST THIS
MORNING...

* WHAT...Snow. Additional snow accumulations of 1 to 2 inches.

* WHERE...Southern Campbell County.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ024-025-072-WYZ057-101800-
/O.CON.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
Northern Black Hills-Northern Foot Hills-
Sturgis/Piedmont Foot Hills-Wyoming Black Hills-
Including Lead, Deadwood, Brownsville, Cheyenne Crossing, Galena,
Nemo, Spearfish, Whitewood, Sturgis, Piedmont, Summerset, 
Sundance, Aladdin, Beulah, and Four Corners
551 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST THIS
MORNING...

* WHAT...Snow. Additional snow accumulations of up to two inches.

* WHERE...In South Dakota, the Sturgis/Piedmont Foot Hills, the 
  Northern Foot Hills and the Northern Black Hills. In Wyoming, 
  the Wyoming Black Hills.

* WHEN...Until 11 AM MST this morning.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ032-073-102100-
/O.CON.KUNR.WW.Y.0013.000000T0000Z-211210T2100Z/
Haakon-Southern Meade Co Plains-
Including Philip and Ellsworth AFB
551 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Snow. Additional snow accumulations of up to two inches.

* WHERE...Haakon County and the Southern Meade County Plains.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$
960 
WWUS43 KUNR 101803
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
1103 AM MST Fri Dec 10 2021


WYZ058-101915-
/O.EXP.KUNR.WS.W.0010.000000T0000Z-211210T1800Z/
Weston-
Including Upton
1103 AM MST Fri Dec 10 2021

...WINTER STORM WARNING HAS EXPIRED...


$$

SDZ024-025-072-WYZ055-057-101915-
/O.EXP.KUNR.WW.Y.0013.000000T0000Z-211210T1800Z/
Northern Black Hills-Northern Foot Hills-
Sturgis/Piedmont Foot Hills-Southern Campbell-Wyoming Black Hills-
Including Lead, Deadwood, Brownsville, Cheyenne Crossing, Galena,
Nemo, Spearfish, Whitewood, Sturgis, Piedmont, Summerset, Wright,
Sundance, Aladdin, Beulah, and Four Corners
1103 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY HAS EXPIRED...



$$

SDZ027>030-041>044-074-102100-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Fall River-Oglala Lakota-Jackson-Bennett-
Hermosa Foot Hills-
Including Edgemont, Hot Springs, Hill City, Mt Rushmore, 
Deerfield, Hisega, Mystic, Pactola Reservoir, Rochford, 
Rockerville, Custer, Jewel Cave, Pringle, Custer State Park, 
Wind Cave, Folsom, Ardmore, Pine Ridge, Oglala, Kyle, Kadoka, 
Martin, Hermosa, Buffalo Gap, and Fairburn
1103 AM MST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Heavy snow. Additional snow accumulations of up to one 
  inch.

* WHERE...Portions of southwestern and the Black Hills of South 
  Dakota. This includes the Tribal Lands of the Pine Ridge 
  Reservation.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ046-047-049-110000-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
1203 PM CST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...

* WHAT...Heavy snow. Additional snow accumulations of up to two 
  inches.

* WHERE...Todd County, Mellette County and Tripp County. This 
  includes the Tribal Lands of the Rosebud Reservation.

* WHEN...Until 6 PM CST this evening.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ026-031-102100-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Rapid City-Pennington Co Plains-
Including Rapid City, Box Elder, Caputa, and Wall
1103 AM MST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Heavy snow. Additional snow accumulations of up to one 
  inch.

* WHERE...The Pennington County Plains and the Rapid City area.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$

SDZ032-073-102100-
/O.CON.KUNR.WW.Y.0013.000000T0000Z-211210T2100Z/
Haakon-Southern Meade Co Plains-
Including Philip and Ellsworth AFB
1103 AM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON...

* WHAT...Snow. Additional snow accumulations of up to one inch.

* WHERE...Haakon County and the Southern Meade County Plains.

* WHEN...Until 2 PM MST this afternoon.

* IMPACTS...Plan on slippery road conditions.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$
815 
WWUS43 KUNR 102100
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
200 PM MST Fri Dec 10 2021


SDZ027>030-041>044-074-102200-
/O.EXP.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Southern Foot Hills-Central Black Hills-Southern Black Hills-
Custer Co Plains-Fall River-Oglala Lakota-Jackson-Bennett-
Hermosa Foot Hills-
Including Edgemont, Hot Springs, Hill City, Mt Rushmore, 
Deerfield, Hisega, Mystic, Pactola Reservoir, Rochford, 
Rockerville, Custer, Jewel Cave, Pringle, Custer State Park, 
Wind Cave, Folsom, Ardmore, Pine Ridge, Oglala, Kyle, Kadoka, 
Martin, Hermosa, Buffalo Gap, and Fairburn
200 PM MST Fri Dec 10 2021

...WINTER STORM WARNING WILL EXPIRE AT 2 PM MST THIS AFTERNOON...


$$

SDZ026-031-102200-
/O.EXP.KUNR.WS.W.0010.000000T0000Z-211210T2100Z/
Rapid City-Pennington Co Plains-
Including Rapid City, Box Elder, Caputa, and Wall
200 PM MST Fri Dec 10 2021

...WINTER STORM WARNING WILL EXPIRE AT 2 PM MST THIS AFTERNOON...


$$

SDZ032-073-102200-
/O.EXP.KUNR.WW.Y.0013.000000T0000Z-211210T2100Z/
Haakon-Southern Meade Co Plains-
Including Philip and Ellsworth AFB
200 PM MST Fri Dec 10 2021

...WINTER WEATHER ADVISORY WILL EXPIRE AT 2 PM MST THIS
AFTERNOON...


$$

SDZ046-047-049-110000-
/O.CON.KUNR.WS.W.0010.000000T0000Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
300 PM CST Fri Dec 10 2021

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...

* WHAT...Heavy snow. Additional snow accumulations of up to two 
  inches.

* WHERE...Todd County, Mellette County and Tripp County. This 
  includes the Tribal Lands of the Rosebud Reservation.

* WHEN...Until 6 PM CST this evening.

* IMPACTS...Plan on slippery road conditions. Patchy blowing 
  snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are expected. This will create dangerous conditions. 

Road conditions are available on your smartphone from the
5 1 1 app for your state.

&&

$$
668 
WWUS43 KUNR 102354
WSWUNR

URGENT - WINTER WEATHER MESSAGE
National Weather Service Rapid City SD
454 PM MST Fri Dec 10 2021

SDZ046-047-049-110100-
/O.EXP.KUNR.WS.W.0010.000000T0000Z-211211T0000Z/
Mellette-Todd-Tripp-
Including White River, Mission, and Winner
554 PM CST Fri Dec 10 2021

...WINTER STORM WARNING WILL EXPIRE AT 6 PM CST THIS EVENING...

Conditions will gradually improve as the snow tapers off this
evening. Therefore, the Winter Storm Warning that was in effect 
for parts of south central South Dakota will be allowed to expire.

$$

What forecasters said that day

The local office's own words before this winter storm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Rapid City, SD wrote its last area forecast discussion before this winter storm warning went out at Dec 8, 10:00 PM MST, 4 hours 10 minutes earlier.

Area forecast discussion, Dec 8, 10:00 PM MST, 4 hours 10 minutes before
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1000 PM MST Wed Dec 8 2021

.DISCUSSION...(This Evening Through Wednesday)
Issued at 239 PM MST Wed Dec 8 2021

Satellite imagery this aftn depicts broad troughing over the wrn
CONUS, with a trof axis and westerly jet streak approaching the
cntrl Rockies. In advance of the trof, an area of enhanced mid-to-
upper-level moisture is evident across the High Plains from wrn TX
nwd into ern MT. Mainly orographically induced high clouds are
streaming across the region this aftn. Predominant flow is southerly
to westerly, supporting a pleasant early December day with temps in
the 40s to 50s.

Cold front (evident on satellite imagery over srn AB this hour) will
cross the northern Plains tonight. Modest enhancement of midlevel RH
coincident with localized area of increased 700-mb fgen may support
some light banded precip with the front. A period of upslope
enhancement tonight given Froude numbers around 1, increased 0-2 km
RH, and increased NW winds (mainly 06-09z) could support some minor
snow accumulations over the nrn Black Hills/Bearlodge Mountains,
though accums should generally be limited to an inch or less given
antecedent dry low-level air. 850-750 mb winds of 40-50 kt could
also support a brief period of gusty NW winds immediately behind the
front, though nocturnal arrival, modest pressure rises (around 3
mb/3 hr), and relatively weak CAA may limit max gust potential.

Bigger story in the short term is the impact of a more substantial
shortwave, which is currently offshore, late tomorrow into Friday.
There is fairly good agreement among models that this mid-to-upper-
level trof will become increasingly amplified as it digs into the
cntrl Rockies tomorrow night. As it approaches, lee cyclogenesis
will lead to an appreciable zone of mid-to-upper-level fgen from ern
WY newd into srn SD. Response to cyclogenesis will also promote a
strengthening of an upper-level jet streak across the Dakotas.
Combination of these factors should support a band of fairly heavy
snow across portions of the cntrl and nrn Plains. Latest trends have
shifted this band slightly nwd, with model consensus painting
heaviest amounts from sern WY toward the NE/SD border. With dry
low-level air in place and sfc low rather far south (tracking
over KS), lift associated with fgen and upper jet will be required
for top- down saturation. As such, expect that area of appreciable
snowfall amounts will be closely tied to this region of lift;
farther north, deeper into the dry air, suspect that amounts will
rapidly taper off, leading to a very tight gradient on the nrn
end. Based on trends, suspect this will be near the I-90 corridor
or just south of there; however, this portion of the forecast
also carries the most uncertainty given recent slight
inconsistencies in track. For now, opted to maintain the Winter
Storm Watch with a slight expansion to the north given recent
trends. Within the heavy band, warning criteria amounts (6" or
more) are likely, so as confidence in placement of this band
increases, suspect some upgrades will be needed in the next 12-24
hours.

Beyond Friday, pattern transitions to broad, amplified troughing
over the wrn CONUS, facilitating another period of dry conditions
with generally above normal temperatures beginning late weekend and
extending thru early next week. Deterministic Euro, GFS, and GEM are
remarkably consistent around the middle of next week at depicting a
robust trof/upper vort max crossing the region, which could lead to
some very impactful weather... to be continued.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Thursday Night)
Issued At 953 PM MST Wed Dec 8 2021

Cold front will move through the region overnight, passing KGCC
around 06Z and KRAP around 08Z with a brief period of gusty
northwest winds. Behind the front, light snow over northeastern
WY and the Black Hills will create some MVFR/local IFR conditions
that will end Thursday morning. After the snow ends, largely VFR
conditions are expected through the day. A stronger storm will
move into the region Thursday evening and overnight, with snow
and deteriorating CIGS/VSBYS developing across far southwest SD
shortly after 00Z and spreading northward towards KRAP after 03Z.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Storm Watch from Thursday evening through Friday morning
     for SDZ027-029-030-041-042-044-074.

     Winter Storm Watch from Thursday evening through Friday
     afternoon for SDZ043-046-047-049.

WY...None.
&&

DISCUSSION...Sherburn
AVIATION...Johnson
Hazardous weather outlook, Dec 9, 2:08 AM MST, 2 minutes before
Hazardous Weather Outlook
National Weather Service Rapid City SD
208 AM MST Thu Dec 9 2021

SDZ001-002-012>014-WYZ071-101400-
Harding-Perkins-Butte-Northern Meade Co Plains-Ziebach-
Northeastern Crook-
208 AM MST Thu Dec 9 2021

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

.DAY ONE...Today and Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

No hazardous weather is expected at this time.

.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

SDZ024-025-032-072-073-WYZ054-056-057-101400-
Northern Black Hills-Northern Foot Hills-Haakon-
Sturgis/Piedmont Foot Hills-Southern Meade Co Plains-
Northern Campbell-Western Crook-Wyoming Black Hills-
208 AM MST Thu Dec 9 2021

This Hazardous Weather Outlook is for portions of western South
Dakota and northeastern Wyoming.

.DAY ONE...Today and Tonight

Light snow will start tonight.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Snow will end Friday, with a few inches of accumulation 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

SDZ026>031-041>044-046-047-049-074-WYZ055-058-101400-
Rapid City-Southern Foot Hills-Central Black Hills-
Southern Black Hills-Custer Co Plains-Pennington Co Plains-
Fall River-Oglala Lakota-Jackson-Bennett-Mellette-Todd-Tripp-
Hermosa Foot Hills-Southern Campbell-Weston-
208 AM MST Thu Dec 9 2021 /308 AM CST Thu Dec 9 2021/

This Hazardous Weather Outlook is for portions of western South
Dakota and northeastern Wyoming.

.DAY ONE...Today and Tonight

Heavy snow will start tonight.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Heavy snow will end Friday. See the latest Winter Weather Message
(WSWUNR) for details.

.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

The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 9, 2:10 AM MSTWinter Weather AdvisoryUNRCuster, Haakon, Lawrence, Meade, Pennington36 hr

Nearby

Winter Storm Warnings in South Dakota, 2021Winter Storm Warnings in Wyoming, 2021Every winter storm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.