Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 157, NWS Sioux Falls, SD

August 31, 2021Bon Homme County, Charles Mix County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 31, 2021, 2:14 AM CDT for Bon Homme County, Charles Mix County, South Dakota. It was in force for 31 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 31, 2021, 2:14 AM CDT (07:14 UTC)
Expired
Aug 31, 2021, 2:45 AM CDT
In force
31 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Bon Homme County, SD, Charles Mix County, SD

The radar

The Sioux Falls radar (KFSD), 131 km from the middle of the area, began a volume at 07:18 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.

IssuedProductOfficeLasted
Aug 30, 9:57 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 7.2 hours before the alert went out and 216 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, Omaha, NE at 00:00Z on 2021-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1443 joules per kilogram.LCLLFCEL10008507005003002001001 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, Omaha, NE at 00:00Z on 2021-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.193958Sfc1 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
1443 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
1305 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.5

Open this sounding in Storm Lab

The text

As transmitted.

717 
WUUS53 KFSD 310714
SVRFSD
SDC009-023-310745-
/O.NEW.KFSD.SV.W.0157.210831T0714Z-210831T0745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
214 AM CDT Tue Aug 31 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Southeastern Charles Mix County in south central South Dakota...
  Southern Bon Homme County in southeastern South Dakota...

* Until 245 AM CDT.

* At 214 AM CDT, a severe thunderstorm was located near Avon, or 12
  miles southwest of Tyndall, moving southeast at 25 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Springfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4277 9806 4284 9815 4284 9818 4287 9825
      4288 9832 4293 9840 4304 9783 4288 9763
      4285 9764 4284 9769 4287 9785 4286 9787
      4281 9789 4277 9794 4276 9803
TIME...MOT...LOC 0714Z 325DEG 22KT 4291 9808 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

APT
2 follow-up statements
639 
WWUS53 KFSD 310735
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
235 AM CDT Tue Aug 31 2021

SDC009-023-310745-
/O.CON.KFSD.SV.W.0157.000000T0000Z-210831T0745Z/
Charles Mix SD-Bon Homme SD-
235 AM CDT Tue Aug 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 AM CDT
FOR SOUTHEASTERN CHARLES MIX AND SOUTHERN BON HOMME COUNTIES...

At 235 AM CDT, a severe thunderstorm was located near Niobrara, or 14
miles southwest of Tyndall, moving southeast at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Springfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4277 9806 4284 9815 4284 9818 4287 9825
      4289 9818 4291 9812 4297 9775 4288 9763
      4285 9764 4284 9769 4287 9785 4286 9787
      4281 9789 4277 9794 4276 9803
TIME...MOT...LOC 0735Z 325DEG 22KT 4280 9798 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

APT
539 
WWUS53 KFSD 310747
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
247 AM CDT Tue Aug 31 2021

SDC009-023-310757-
/O.EXP.KFSD.SV.W.0157.000000T0000Z-210831T0745Z/
Charles Mix SD-Bon Homme SD-
247 AM CDT Tue Aug 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CHARLES MIX AND
SOUTHERN BON HOMME COUNTIES HAS EXPIRED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has 
been allowed to expire. However gusty winds are still possible with 
this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 500 AM CDT for
south central and southeastern South Dakota.

LAT...LON 4277 9806 4284 9815 4284 9818 4287 9825
      4289 9818 4291 9812 4297 9775 4288 9763
      4285 9764 4284 9769 4287 9785 4286 9787
      4281 9789 4277 9794 4276 9803
TIME...MOT...LOC 0747Z 325DEG 22KT 4274 9793 

$$

APT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 7:29 PM CDTSevere Thunderstorm WarningFSDClay, Union46 min
Aug 30, 7:57 PM CDTSevere Thunderstorm WarningFSDHutchinson, McCook, Minnehaha, Turner48 min
Aug 30, 11:19 PM CDTSevere Thunderstorm WarningFSDBeadle, Jerauld, Sanborn41 min
Aug 31, 12:00 AM CDTFlash Flood WarningFSDAurora, Brule3 hr
Aug 31, 12:05 AM CDTSevere Thunderstorm WarningFSDAurora, Davison, Douglas40 min
Aug 31, 12:15 AM CDTSevere Thunderstorm WarningFSDHanson, Hutchinson45 min
Aug 31, 1:26 AM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix, Gregory49 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2021Every 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.