Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 60, NWS Sioux Falls, SD

July 23, 2021Kingsbury County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 23, 2021, 9:06 PM CDT for Kingsbury County, South Dakota. It was in force for 39 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: Jul 23, 2021, 9:06 PM CDT (02:06 UTC)
Expired: Jul 23, 2021, 9:45 PM CDT
In force: 39 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Kingsbury County, SD

The radar

The Sioux Falls radar (KFSD), 115 km from the middle of the area, began a volume at 02:08 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 nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 2.1 hours before the alert went out and 86 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: 3002 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 1613 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 53 m²/s²
0-3 km storm-relative helicity: 89 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 6.9

Open this sounding in Storm Lab

The text

As transmitted.

974 
WUUS53 KFSD 240206
SVRFSD
SDC077-240245-
/O.NEW.KFSD.SV.W.0060.210724T0206Z-210724T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
906 PM CDT Fri Jul 23 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northern Kingsbury County in east central South Dakota...

* Until 945 PM CDT.

* At 906 PM CDT, a severe thunderstorm was located 7 miles northeast
  of Iroquois, or 15 miles northwest of Lake Thompson State
  Recreation Area, moving east at 25 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  De Smet around 925 PM CDT.

Other locations impacted by this severe thunderstorm include Bancroft
and Erwin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4441 9723 4430 9785 4448 9785 4454 9762
      4454 9736
TIME...MOT...LOC 0206Z 250DEG 22KT 4443 9773 

HAIL...<.75IN
WIND...60MPH
 
$$

Chapman

2 follow-up statements

853 
WWUS53 KFSD 240220
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
920 PM CDT Fri Jul 23 2021

SDC077-240245-
/O.CON.KFSD.SV.W.0060.000000T0000Z-210724T0245Z/
Kingsbury SD-
920 PM CDT Fri Jul 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT
FOR NORTHERN KINGSBURY COUNTY...

At 920 PM CDT, a severe thunderstorm was located near De Smet, or 10
miles northwest of Lake Thompson State Recreation Area, moving east
at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

This severe storm will be near...
  De Smet around 925 PM CDT.
  Erwin around 940 PM CDT.

Other locations impacted by this severe thunderstorm include Erwin.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4432 9773 4445 9779 4454 9762 4454 9736
      4441 9723
TIME...MOT...LOC 0220Z 262DEG 22KT 4442 9760 

HAIL...<.75IN
WIND...60MPH
 
$$

Chapman

236 
WWUS53 KFSD 240239
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
939 PM CDT Fri Jul 23 2021

SDC077-240249-
/O.EXP.KFSD.SV.W.0060.000000T0000Z-210724T0245Z/
Kingsbury SD-
939 PM CDT Fri Jul 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN KINGSBURY COUNTY WILL
EXPIRE AT 945 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.  However, gusty 
winds of 40 to 45 mph are still possible with this thunderstorm.

LAT...LON 4432 9773 4445 9779 4454 9762 4454 9736
      4441 9723
TIME...MOT...LOC 0239Z 250DEG 22KT 4445 9747 

$$

Chapman

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 9:11 PM CDT	Severe Thunderstorm Warning	FSD	Aurora, Davison, Hanson	49 min
Jul 23, 9:15 PM CDT	Severe Thunderstorm Warning	FSD	Kingsbury	30 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.