Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 94, NWS Sioux Falls, SD

August 22, 20214 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 22, 2021, 7:15 PM CDT for 4 counties in South Dakota. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 22, 2021, 7:15 PM CDT (00:15 UTC)
Expired: Aug 22, 2021, 7:45 PM CDT
In force: 30 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Damage threat: Considerable
Hail: 2.0 in
Wind: 70.0 mph

Counties Davison County, SD, Hanson County, SD, Miner County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 90 km from the middle of the area, began a volume at 00:13 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 22, 3:36 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
Aug 22, 6:31 PM CDT	Tornado Watch	SPC	3 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 0.3 hours before the alert went out and 126 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 166 J/kg
Mixed-layer CIN: -152 J/kg
Mixed-layer LCL: 1323 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 245 m²/s²
0-3 km storm-relative helicity: 282 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted.

902 
WUUS53 KFSD 230015
SVRFSD
SDC035-061-097-111-230045-
/O.NEW.KFSD.SV.W.0094.210823T0015Z-210823T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
715 PM CDT Sun Aug 22 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northeastern Davison County in southeastern South Dakota...
  Southeastern Sanborn County in east central South Dakota...
  Southwestern Miner County in east central South Dakota...
  Northern Hanson County in southeastern South Dakota...

* Until 745 PM CDT.

* At 714 PM CDT, a severe thunderstorm was located near Loomis, or 8
  miles north of Mitchell, moving east at 45 mph.

  HAZARD...Two inch hail and 70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings.

* This severe thunderstorm will be near...
  Fulton around 730 PM CDT.

Other locations in the path of this severe thunderstorm include
Farmer.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
and east central South Dakota.

For your protection move to an interior room on the lowest floor of a
building.

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
and east central South Dakota.

&&

LAT...LON 4391 9762 4384 9761 4369 9761 4379 9816
      4396 9811
TIME...MOT...LOC 0014Z 279DEG 39KT 4386 9803 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...2.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

Schumacher

2 follow-up statements

738 
WWUS53 KFSD 230027
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
727 PM CDT Sun Aug 22 2021

SDC035-061-097-111-230045-
/O.CON.KFSD.SV.W.0094.000000T0000Z-210823T0045Z/
Davison SD-Sanborn SD-Miner SD-Hanson SD-
727 PM CDT Sun Aug 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR NORTHEASTERN DAVISON...SOUTHEASTERN SANBORN...SOUTHWESTERN MINER
AND NORTHERN HANSON COUNTIES...

At 727 PM CDT, a severe thunderstorm was located 9 miles northwest of
Fulton, or 9 miles northeast of Mitchell, moving east at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

This severe thunderstorm will remain over mainly rural areas of
northeastern Davison, southeastern Sanborn, southwestern Miner and
northern Hanson Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
and east central South Dakota.

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4391 9762 4384 9761 4373 9761 4379 9805
      4395 9801
TIME...MOT...LOC 0027Z 279DEG 27KT 4385 9793 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Schumacher

029 
WWUS53 KFSD 230040
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
740 PM CDT Sun Aug 22 2021

SDC035-061-097-111-230049-
/O.EXP.KFSD.SV.W.0094.000000T0000Z-210823T0045Z/
Davison SD-Sanborn SD-Miner SD-Hanson SD-
740 PM CDT Sun Aug 22 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN DAVISON...
SOUTHEASTERN SANBORN...SOUTHWESTERN MINER AND NORTHERN HANSON
COUNTIES WILL EXPIRE AT 745 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

A severe thunderstorm warning remains in effect for northern Davison 
and southern Sanborn counties until 815 PM CDT for a second storm 
moving east from Aurora County.

A Tornado Watch remains in effect until 1000 PM CDT for southeastern
and east central South Dakota.

LAT...LON 4391 9762 4384 9761 4373 9761 4379 9805
      4395 9801
TIME...MOT...LOC 0039Z 279DEG 39KT 4383 9777 

$$

Schumacher

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 22, 7:21 PM CDT	Severe Thunderstorm Warning	FSD	Aurora	24 min
Aug 22, 7:31 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Davison, Sanborn	44 min
Aug 22, 8:06 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Davison, Hanson, Miner, Sanborn	39 min
Aug 22, 8:32 PM CDT	Severe Thunderstorm Warning	FSD	Hanson, McCook	43 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2021 Every severe thunderstorm 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.