Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 96, NWS Sioux Falls, SD

August 22, 2021Davison County, Sanborn County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 22, 2021, 7:31 PM CDT for Davison County, Sanborn County, South Dakota. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 22, 2021, 7:31 PM CDT (00:31 UTC)
Expired: Aug 22, 2021, 8:15 PM CDT
In force: 44 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Damage threat: Considerable
Hail: 1.75 in
Wind: 60.0 mph

Counties Davison County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 115 km from the middle of the area, began a volume at 00:34 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

Time	Report	Where	Remark
Aug 22, 7:48 PM CDT	HAIL 1	3 Sw Letcher, SD

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

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, 0.5 hours before the alert went out and 118 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.

017 
WUUS53 KFSD 230031
SVRFSD
SDC035-111-230115-
/O.NEW.KFSD.SV.W.0096.210823T0031Z-210823T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
731 PM CDT Sun Aug 22 2021

The National Weather Service in Sioux Falls has issued a

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

* Until 815 PM CDT.

* At 731 PM CDT, a severe thunderstorm was located over Storla, or 11
  miles northeast of Plankinton, moving east at 30 mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Letcher around 755 PM CDT.
  Loomis around 800 PM CDT.
  Mitchell around 805 PM CDT.

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 4393 9796 4372 9797 4377 9832 4394 9833
TIME...MOT...LOC 0031Z 279DEG 27KT 4387 9839 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Schumacher

2 follow-up statements

955 
WWUS53 KFSD 230051
SVSFSD

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

SDC035-111-230115-
/O.CON.KFSD.SV.W.0096.000000T0000Z-210823T0115Z/
Davison SD-Sanborn SD-
751 PM CDT Sun Aug 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR NORTHERN DAVISON AND SOUTHWESTERN SANBORN COUNTIES...

At 751 PM CDT, a severe thunderstorm was located near Letcher, or 10
miles northwest of Mitchell, moving east at 30 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.

Locations impacted include...
  Loomis and Mitchell.

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 4372 9797 4377 9832 4391 9827 4391 9796
TIME...MOT...LOC 0051Z 279DEG 27KT 4385 9818 

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

$$

Schumacher

361 
WWUS53 KFSD 230103
SVSFSD

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

SDC035-111-230115-
/O.CON.KFSD.SV.W.0096.000000T0000Z-210823T0115Z/
Davison SD-Sanborn SD-
803 PM CDT Sun Aug 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR NORTHERN DAVISON AND SOUTHWESTERN SANBORN COUNTIES...

At 801 PM CDT, a severe thunderstorm was located near Loomis, or 7
miles north of Mitchell, moving east at 30 mph.

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

SOURCE...Trained weather spotters. At 752 PM CDT, quarter size hail 
         was reported 3 miles southwest of Letcher.

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.

Locations impacted include...
Mitchell, Letcher and Loomis. 

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 4372 9797 4377 9832 4391 9827 4391 9796
TIME...MOT...LOC 0101Z 279DEG 27KT 4384 9807 

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

$$

Schumacher

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 7:15 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Davison, Hanson, Miner, Sanborn	30 min
Aug 22, 7:21 PM CDT	Severe Thunderstorm Warning	FSD	Aurora	24 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.