Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 159, NWS Sioux Falls, SD

September 16, 20214 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 16, 2021, 11:31 PM CDT for 4 counties in South Dakota. It was in force for 29 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
Sep 16, 2021, 11:31 PM CDT (04:31 UTC)
Expired
Sep 17, 2021, 12:00 AM CDT
In force
29 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

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

The radar

The Sioux Falls radar (KFSD), 122 km from the middle of the area, began a volume at 04:33 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
Sep 16, 11:43 PM CDTTSTM WND DMG1 E Tyndall, SDBRANCHES DOWN IN TYNDALL INCLUDING 8 INCH DIAMETER BRANCH ON EAST SIDE OF TOWN.

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
Sep 16, 8:16 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.5 hours before the alert went out and 213 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 2021-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 612 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 2021-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.1939Sfc1 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
612 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
2155 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
132 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

880 
WUUS53 KFSD 170431
SVRFSD
SDC009-023-067-135-170500-
/O.NEW.KFSD.SV.W.0159.210917T0431Z-210917T0500Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1131 PM CDT Thu Sep 16 2021

The National Weather Service in Sioux Falls has issued a

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

* Until midnight CDT.

* At 1130 PM CDT, a severe thunderstorm was located near Avon, or 9
  miles southwest of Tyndall, moving northeast at 60 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 be near...
  Springfield around 1135 PM CDT.
  Tyndall around 1140 PM CDT.
  Tabor around 1150 PM CDT.
  Scotland around 1155 PM CDT.

Other locations impacted by this severe thunderstorm include
Lesterville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4284 9815 4285 9821 4297 9826 4326 9761
      4286 9750 4285 9758 4286 9762 4284 9769
      4287 9785 4286 9787 4281 9789 4278 9793
      4276 9803
TIME...MOT...LOC 0430Z 240DEG 50KT 4293 9803 

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

$$

SG
2 follow-up statements
948 
WWUS53 KFSD 170444
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1144 PM CDT Thu Sep 16 2021

SDC023-170453-
/O.CAN.KFSD.SV.W.0159.000000T0000Z-210917T0500Z/
Charles Mix SD-
1144 PM CDT Thu Sep 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN CHARLES MIX
COUNTY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4326 9761 4286 9750 4285 9758 4286 9762
      4284 9769 4287 9785 4286 9787 4281 9789
      4278 9793 4291 9800 4306 9807
TIME...MOT...LOC 0443Z 240DEG 47KT 4298 9785 

$$

SDC009-067-135-170500-
/O.CON.KFSD.SV.W.0159.000000T0000Z-210917T0500Z/
Bon Homme SD-Yankton SD-Hutchinson SD-
1144 PM CDT Thu Sep 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT
FOR BON HOMME...WESTERN YANKTON AND SOUTH CENTRAL HUTCHINSON
COUNTIES...

At 1143 PM CDT, a severe thunderstorm was located over Tyndall,
moving northeast at 55 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.

This severe storm will be near...
  Tabor around 1150 PM CDT.
  Scotland around 1155 PM CDT.

Other locations impacted by this severe thunderstorm include
Lesterville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4326 9761 4286 9750 4285 9758 4286 9762
      4284 9769 4287 9785 4286 9787 4281 9789
      4278 9793 4291 9800 4306 9807
TIME...MOT...LOC 0443Z 240DEG 47KT 4298 9785 

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

$$

SG
407 
WWUS53 KFSD 170458
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1158 PM CDT Thu Sep 16 2021

SDC009-067-135-170507-
/O.EXP.KFSD.SV.W.0159.000000T0000Z-210917T0500Z/
Bon Homme SD-Yankton SD-Hutchinson SD-
1158 PM CDT Thu Sep 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR BON HOMME...WESTERN YANKTON
AND SOUTH CENTRAL HUTCHINSON COUNTIES WILL EXPIRE AT MIDNIGHT 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 are still possible with this thunderstorm.

LAT...LON 4326 9761 4286 9750 4285 9758 4286 9762
      4284 9769 4287 9785 4286 9787 4281 9789
      4278 9793 4291 9800 4306 9807
TIME...MOT...LOC 0457Z 239DEG 48KT 4305 9768 

$$

SG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 10:20 PM CDTSevere Thunderstorm WarningFSDCharles Mix, Gregory25 min
Sep 17, 12:10 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDBrookings, Lake, McCook, Minnehaha, Moody35 min
Sep 17, 12:29 AM CDTSevere Thunderstorm WarningFSDClay, Lincoln, Turner, Union, Yankton46 min
Sep 17, 12:34 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDMinnehaha56 min
Sep 17, 12:36 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDLincoln, Minnehaha54 min
Sep 17, 1:11 AM CDTSevere Thunderstorm WarningFSDUnion49 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.