Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 156, NWS Sioux Falls, SD

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

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 31, 2021, 1:26 AM CDT for Bon Homme County, Charles Mix County, Gregory County, South Dakota. It was in force for 49 min. 2 reports 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 31, 2021, 1:26 AM CDT (06:26 UTC)
Expired
Aug 31, 2021, 2:15 AM CDT
In force
49 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, Gregory County, SD

The radar

The Sioux Falls radar (KFSD), 159 km from the middle of the area, began a volume at 06:28 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
Aug 31, 1:41 AM CDTTSTM WND GST 552 Wsw Pickstown, SDMESONET STATION 244 SD RWIS FT. RANDALL DAM.
Aug 31, 1:58 AM CDTTSTM WND GST 501 E Wagner, SDPERSONAL WEATHER STATION RECORDED WIND GUST OF 50 MPH.

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.

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

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 6.4 hours before the alert went out and 214 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, Aberdeen, SD at 00:00Z on 2021-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 205 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 00:00Z on 2021-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
205 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
1953 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

981 
WUUS53 KFSD 310626
SVRFSD
SDC009-023-053-310715-
/O.NEW.KFSD.SV.W.0156.210831T0626Z-210831T0715Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
126 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...
  Gregory County in south central South Dakota...
  Southern Bon Homme County in southeastern South Dakota...

* Until 215 AM CDT.

* At 125 AM CDT, severe thunderstorms were located along a line
  extending from 6 miles north of Ravinia to 8 miles north of
  Bonesteel to near Gregory, moving southeast at 40 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.

* Severe thunderstorms will be near...
  Lake Andes and Ravinia around 130 AM CDT.
  Bonesteel around 135 AM CDT.
  Wagner and Herrick around 145 AM CDT.
  Dante and St. Charles around 150 AM CDT.
  Pickstown around 155 AM CDT.
  Avon around 200 AM CDT.
  Springfield around 215 AM CDT.

Other locations impacted by these severe thunderstorms include
Fairfax and Yankton Sioux Tribal Nation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4326 9953 4325 9832 4284 9769 4287 9785
      4277 9794 4276 9803 4284 9815 4293 9844
      4300 9850 4300 9953
TIME...MOT...LOC 0625Z 311DEG 35KT 4322 9845 4320 9894 4322 9939 

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

$$

APT
1 follow-up statement
927 
WWUS53 KFSD 310701
SVSFSD

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

SDC009-023-053-310715-
/O.CON.KFSD.SV.W.0156.000000T0000Z-210831T0715Z/
Charles Mix SD-Gregory SD-Bon Homme SD-
201 AM CDT Tue Aug 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 AM CDT
FOR SOUTHEASTERN CHARLES MIX...SOUTHEASTERN GREGORY AND SOUTHERN BON
HOMME COUNTIES...

At 201 AM CDT, severe thunderstorms were located along a line
extending from near Avon to near Gross to 7 miles northeast of Butte,
moving southeast at 40 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.

These severe storms will be near...
  Avon and Dante around 205 AM CDT.
  Marty around 210 AM CDT.
  Springfield around 225 AM CDT.

Other locations impacted by these severe thunderstorms include
Yankton Sioux Tribal Nation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4318 9888 4319 9823 4284 9769 4287 9785
      4277 9794 4276 9803 4284 9815 4293 9844
      4300 9850 4300 9886
TIME...MOT...LOC 0701Z 310DEG 35KT 4300 9811 4298 9860 4301 9879 

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

$$

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, 2:14 AM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix31 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.