Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 18, NWS Sioux Falls, SD

June 11, 2021Yankton County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 11, 2021, 5:41 AM CDT for Yankton County, South Dakota. It was in force for 34 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: Jun 11, 2021, 5:41 AM CDT (10:41 UTC)
Expired: Jun 11, 2021, 6:15 AM CDT
In force: 34 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Yankton County, SD

The radar

The Sioux Falls radar (KFSD), 93 km from the middle of the area, began a volume at 10:40 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
Jun 11, 5:43 AM CDT	TSTM WND GST 58	6 Sw Mayfield, SD	TIME ESTIMATED VIA RADAR. REPORTED GUSTS TO 60 MPH ELSEWHERE IN COUNTY.
Jun 11, 5:56 AM CDT	TSTM WND GST 56	2 Ne Yankton, 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
Jun 11, 2:15 AM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 10.7 hours before the alert went out and 194 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: 1135 J/kg
Mixed-layer CIN: -96 J/kg
Mixed-layer LCL: 2153 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 85 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

The text

As transmitted.

790 
WUUS53 KFSD 111041
SVRFSD
SDC135-111115-
/O.NEW.KFSD.SV.W.0018.210611T1041Z-210611T1115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
541 AM CDT Fri Jun 11 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Yankton County in southeastern South Dakota...

* Until 615 AM CDT.

* At 541 AM CDT, severe thunderstorms were located along a line
  extending from near Mayfield to near Lewis And Clark State
  Recreation Area, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Mayfield around 550 AM CDT.
  Irene around 600 AM CDT.
  Volin around 605 AM CDT.

Other locations impacted by these severe thunderstorms include Lewis
And Clark State Recreation Area and Gayville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4281 9721 4285 9723 4287 9730 4285 9736
      4287 9741 4285 9744 4286 9750 4285 9753
      4285 9764 4290 9764 4317 9749 4317 9716
      4280 9716
TIME...MOT...LOC 1041Z 285DEG 34KT 4312 9741 4282 9758 

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

Schumacher

2 follow-up statements

110 
WWUS53 KFSD 111100
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
600 AM CDT Fri Jun 11 2021

SDC135-111115-
/O.CON.KFSD.SV.W.0018.000000T0000Z-210611T1115Z/
Yankton SD-
600 AM CDT Fri Jun 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 AM CDT
FOR EASTERN YANKTON COUNTY...

At 559 AM CDT, severe thunderstorms were located along a line
extending from Irene to 7 miles south of Yankton, moving east at 40
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated. At 550 AM CDT, a 56 mph wind gust was 
         reported at the airport in Yankton.

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

These severe storms will be near...
  Volin around 605 AM CDT.

Other locations impacted by these severe thunderstorms include Lewis
And Clark State Recreation Area and Gayville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4281 9721 4285 9723 4287 9730 4285 9736
      4287 9741 4285 9744 4286 9750 4285 9753
      4297 9739 4317 9745 4317 9716 4280 9716
TIME...MOT...LOC 1059Z 285DEG 34KT 4308 9718 4278 9735 

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

Schumacher

145 
WWUS53 KFSD 111113
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
613 AM CDT Fri Jun 11 2021

SDC135-111123-
/O.EXP.KFSD.SV.W.0018.000000T0000Z-210611T1115Z/
Yankton SD-
613 AM CDT Fri Jun 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN YANKTON COUNTY WILL
EXPIRE AT 615 AM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 700 AM CDT for
southeastern South Dakota.

LAT...LON 4281 9721 4285 9723 4287 9730 4285 9736
      4287 9741 4285 9744 4286 9750 4285 9753
      4297 9739 4317 9745 4317 9716 4280 9716
TIME...MOT...LOC 1113Z 285DEG 34KT 4305 9701 4275 9718 

$$

Schumacher

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 11, 3:13 AM CDT	Severe Thunderstorm Warning	FSD	Brule, Charles Mix, Gregory	47 min
Jun 11, 3:26 AM CDT	Severe Thunderstorm Warning	FSD	Beadle, Jerauld	64 min
Jun 11, 3:39 AM CDT	Severe Thunderstorm Warning	FSD	Aurora, Charles Mix, Douglas, Gregory	51 min
Jun 11, 4:59 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Charles Mix	46 min
Jun 11, 5:04 AM CDT	Severe Thunderstorm Warning	FSD	Brookings, Kingsbury, Lake, Miner	41 min
Jun 11, 5:56 AM CDT	Severe Thunderstorm Warning	FSD	Clay, Union	49 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.