Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 149, NWS Sioux Falls, SD

August 30, 2021Clay County, Union County, South Dakota; Plymouth County, Sioux County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 30, 2021, 7:29 PM CDT for Clay County, Union County, South Dakota; Plymouth County, Sioux County, Iowa. It was in force for 46 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 30, 2021, 7:29 PM CDT (00:29 UTC)
Expired: Aug 30, 2021, 8:15 PM CDT
In force: 46 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Plymouth County, IA, Sioux County, IA, Clay County, SD, Union County, SD

The radar

The Sioux Falls radar (KFSD), 71 km from the middle of the area, began a volume at 00:31 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 30, 7:32 PM CDT	HAIL 1.75	6 S Beresford, SD
Aug 30, 7:38 PM CDT	HAIL 0.75	7 Sw Alcester, SD

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

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.5 hours before the alert went out and 184 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: 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.

388 
WUUS53 KFSD 310029
SVRFSD
IAC149-167-SDC027-127-310115-
/O.NEW.KFSD.SV.W.0149.210831T0029Z-210831T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
729 PM CDT Mon Aug 30 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Southwestern Sioux County in northwestern Iowa...
  Northwestern Plymouth County in northwestern Iowa...
  Northeastern Clay County in southeastern South Dakota...
  Northern Union County in southeastern South Dakota...

* Until 815 PM CDT.

* At 728 PM CDT, a severe thunderstorm was located near Union Grove
  State Park, or 7 miles south of Beresford, moving east 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.

* This severe thunderstorm will be near...
  Alcester around 745 PM CDT.
  Akron around 805 PM CDT.

Other locations impacted by this severe thunderstorm include
Chatsworth.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4293 9692 4300 9690 4307 9681 4301 9640
      4275 9652
TIME...MOT...LOC 0028Z 289DEG 23KT 4297 9680 

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

$$

BP

2 follow-up statements

875 
WWUS53 KFSD 310045
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
745 PM CDT Mon Aug 30 2021

SDC027-310054-
/O.CAN.KFSD.SV.W.0149.000000T0000Z-210831T0115Z/
Clay SD-
745 PM CDT Mon Aug 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CLAY 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 4288 9680 4296 9680 4305 9668 4301 9640
      4275 9652
TIME...MOT...LOC 0044Z 289DEG 23KT 4294 9666 

$$

IAC149-167-SDC127-310115-
/O.CON.KFSD.SV.W.0149.000000T0000Z-210831T0115Z/
Sioux IA-Plymouth IA-Union SD-
745 PM CDT Mon Aug 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHWESTERN SIOUX...NORTHWESTERN PLYMOUTH AND NORTHERN UNION
COUNTIES...

At 744 PM CDT, a severe thunderstorm was located near Union Grove
State Park, or 10 miles southwest of Hawarden, moving east 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.

This severe storm will be near...
  Akron around 800 PM CDT.

Other locations impacted by this severe thunderstorm include
Chatsworth.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Sioux Falls.

&&

LAT...LON 4288 9680 4296 9680 4305 9668 4301 9640
      4275 9652
TIME...MOT...LOC 0044Z 289DEG 23KT 4294 9666 

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

$$

BP

387 
WWUS53 KFSD 310101
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
801 PM CDT Mon Aug 30 2021

IAC149-167-SDC127-310115-
/O.CON.KFSD.SV.W.0149.000000T0000Z-210831T0115Z/
Sioux IA-Plymouth IA-Union SD-
801 PM CDT Mon Aug 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR SOUTHWESTERN SIOUX...NORTHWESTERN PLYMOUTH AND CENTRAL UNION
COUNTIES...

At 801 PM CDT, a severe thunderstorm was located near Akron, or near
Hawarden, moving east 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.

This severe thunderstorm will remain over mainly rural areas of
southwestern Sioux, northwestern Plymouth and central Union Counties,
including the following locations... Chatsworth.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Sioux Falls.

&&

LAT...LON 4284 9672 4293 9656 4299 9652 4297 9642
      4275 9652
TIME...MOT...LOC 0101Z 289DEG 23KT 4290 9651 

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

$$

BP

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 30, 7:57 PM CDT	Severe Thunderstorm Warning	FSD	Hutchinson, McCook, Minnehaha, Turner	48 min
Aug 30, 11:19 PM CDT	Severe Thunderstorm Warning	FSD	Beadle, Jerauld, Sanborn	41 min
Aug 31, 12:00 AM CDT	Flash Flood Warning	FSD	Aurora, Brule	3 hr
Aug 31, 12:05 AM CDT	Severe Thunderstorm Warning	FSD	Aurora, Davison, Douglas	40 min
Aug 31, 12:15 AM CDT	Severe Thunderstorm Warning	FSD	Hanson, Hutchinson	45 min
Aug 31, 1:26 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Charles Mix, Gregory	49 min
Aug 31, 2:14 AM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Charles Mix	31 min
Aug 30, 9:49 PM CDT	Severe Thunderstorm Warning	FSD	Ida	26 min
Aug 30, 10:05 PM CDT	Severe Thunderstorm Warning	FSD	Ida	10 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2021 Severe Thunderstorm Warnings in Iowa, 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.