Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 76, NWS Sioux Falls, SD

August 5, 2021Lincoln County, Minnehaha County, South Dakota; Rock County, Minnesota; Lyon County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 5, 2021, 8:57 PM CDT for Lincoln County, Minnehaha County, South Dakota; Rock County, Minnesota; Lyon County, Iowa. It was in force for 48 min. 7 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 5, 2021, 8:57 PM CDT (01:57 UTC)
Expired
Aug 5, 2021, 9:45 PM CDT
In force
48 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Damage threat
Considerable
Hail
1.5 in
Wind
70.0 mph

Counties Lyon County, IA, Rock County, MN, Lincoln County, SD, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 11 km from the middle of the area, began a volume at 01:59 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 5, 8:58 PM CDTTSTM WND DMG3 W Rowena, SDDELAYED REPORT. PORTION OF DECK OVERHANG AND ROOF BLOWN OFF. TIME ESTIMATED VIA RADAR.
Aug 5, 8:59 PM CDTTSTM WND DMG4 Ese Sioux Falls, SDSEVERAL 8 YEAR OLD PINE TREES UPROOTED. TIME ESTIMATED BY RADAR. VIA SOCIAL MEDIA PICTURE.
Aug 5, 9:00 PM CDTHAIL 1.5Brandon, SDVIA SOCIAL MEDIA PICTURE.
Aug 5, 9:04 PM CDTHAIL 2.55 Ese Crooks, SDREPORT VIA SOCIAL MEDIA.
Aug 5, 9:08 PM CDTHAIL 14 Wnw Rowena, SD
Aug 5, 9:10 PM CDTHAIL 24 Wnw Rowena, SD
Aug 5, 9:13 PM CDTTSTM WND DMG2 Wnw Rowena, SDSEVERAL LARGE TREE BRANCHES DOWN AT THE MARY JO WEGNER ARBORETUM, SOME AS LARGE AS A FOOT IN DIAMETER. TIME ESTIMATED VIA RADAR AND NEARBY GROUND OBSERVATIONS.

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

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 2.0 hours before the alert went out and 208 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 2021-08-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 835 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 2021-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
835 J/kg
Mixed-layer CIN
-42 J/kg
Mixed-layer LCL
1549 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
259 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

953 
WUUS53 KFSD 060157
SVRFSD
IAC119-MNC133-SDC083-099-060245-
/O.NEW.KFSD.SV.W.0076.210806T0157Z-210806T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
857 PM CDT Thu Aug 5 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northwestern Lyon County in northwestern Iowa...
  Southwestern Rock County in southwestern Minnesota...
  Southeastern Minnehaha County in southeastern South Dakota...
  Northeastern Lincoln County in southeastern South Dakota...

* Until 945 PM CDT.

* At 857 PM CDT, a severe thunderstorm was located near Brandon, or
  near Sioux Falls, moving south at 30 mph.

  HAZARD...70 mph wind gusts and ping pong ball size hail.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings.

Other locations in the path of this severe thunderstorm include Lake
Alvin State Recreation Area and Canton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4364 9680 4371 9653 4339 9621 4325 9680
TIME...MOT...LOC 0157Z 344DEG 27KT 4360 9666 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

SSC
3 follow-up statements
547 
WWUS53 KFSD 060215
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
915 PM CDT Thu Aug 5 2021

IAC119-MNC133-SDC083-099-060245-
/O.CON.KFSD.SV.W.0076.000000T0000Z-210806T0245Z/
Lyon IA-Rock MN-Minnehaha SD-Lincoln SD-
915 PM CDT Thu Aug 5 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT
FOR NORTHWESTERN LYON...SOUTHWESTERN ROCK...SOUTHEASTERN MINNEHAHA
AND NORTHEASTERN LINCOLN COUNTIES...

At 915 PM CDT, Doppler radar indicated a severe thunderstorm capable
of producing half dollar size hail and destructive winds in excess of
70 mph. This storm was located over Lake Alvin State Recreation Area,
or 8 miles southeast of Sioux Falls, moving south at 30 mph.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you are in the path of this storm, prepare immediately for large
hail and damaging winds. People outside should move to a shelter,
preferably inside a strong building and away from windows.

In addition to large hail and damaging winds, continuous cloud to
ground lightning is occurring with this storm.  Move indoors
immediately. Lightning is one of nature's leading killers. Remember,
if you can hear thunder, you are close enough to be struck by
lightning.

&&

LAT...LON 4358 9665 4366 9649 4339 9621 4329 9665
TIME...MOT...LOC 0215Z 344DEG 27KT 4347 9661 

$$

SSC
895 
WWUS53 KFSD 060227
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
927 PM CDT Thu Aug 5 2021

MNC133-SDC099-060237-
/O.CAN.KFSD.SV.W.0076.000000T0000Z-210806T0245Z/
Rock MN-Minnehaha SD-
927 PM CDT Thu Aug 5 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN ROCK AND
SOUTHEASTERN MINNEHAHA COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4350 9659 4350 9633 4339 9621 4332 9655
TIME...MOT...LOC 0227Z 344DEG 27KT 4338 9658 

$$

IAC119-SDC083-060245-
/O.CON.KFSD.SV.W.0076.000000T0000Z-210806T0245Z/
Lyon IA-Lincoln SD-
927 PM CDT Thu Aug 5 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT
FOR NORTHWESTERN LYON AND NORTHEASTERN LINCOLN COUNTIES...

At 927 PM CDT, Doppler radar indicated a severe thunderstorm capable
of producing half dollar size hail and destructive winds in excess of
70 mph. This storm was located near Lake Alvin State Recreation Area,
or near Canton, moving south at 30 mph.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you are in the path of this storm, prepare immediately for large
hail and damaging winds. People outside should move to a shelter,
preferably inside a strong building and away from windows.

In addition to large hail and damaging winds, continuous cloud to
ground lightning is occurring with this storm.  Move indoors
immediately. Lightning is one of nature's leading killers. Remember,
if you can hear thunder, you are close enough to be struck by
lightning.

&&

LAT...LON 4350 9659 4350 9633 4339 9621 4332 9655
TIME...MOT...LOC 0227Z 344DEG 27KT 4338 9658 

$$

SSC
529 
WWUS53 KFSD 060236
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
936 PM CDT Thu Aug 5 2021

IAC119-SDC083-060246-
/O.EXP.KFSD.SV.W.0076.000000T0000Z-210806T0245Z/
Lyon IA-Lincoln SD-
936 PM CDT Thu Aug 5 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN LYON AND
NORTHEASTERN LINCOLN COUNTIES WILL EXPIRE AT 945 PM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small
hail, gusty winds and heavy rain are still possible with this
thunderstorm.

Remember, a Severe Thunderstorm Warning still remains in effect for 
Lyon County until 8:15 PM.

LAT...LON 4350 9659 4350 9633 4339 9621 4332 9655
TIME...MOT...LOC 0236Z 344DEG 27KT 4333 9656 

$$

SSC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 7:00 PM CDTSevere Thunderstorm WarningFSDLake, Moody45 min
Aug 5, 7:28 PM CDTSevere Thunderstorm WarningFSDBrookings, Moody32 min
Aug 5, 7:44 PM CDTSevere Thunderstorm WarningFSDMoody33 min
Aug 5, 7:58 PM CDTSevere Thunderstorm WarningFSDLake, Minnehaha, Moody47 min
Aug 5, 8:24 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDMinnehaha, Moody51 min
Aug 5, 9:04 PM CDTSevere Thunderstorm WarningFSDMinnehaha28 min
Aug 5, 10:04 PM CDTSevere Thunderstorm WarningFSDLincoln, McCook, Minnehaha, Turner41 min
Aug 5, 10:36 PM CDTSevere Thunderstorm WarningFSDClay, Lincoln, Turner, Union39 min
Aug 5, 11:40 PM CDTSevere Thunderstorm WarningFSDMinnehaha50 min
Aug 6, 12:10 AM CDTSevere Thunderstorm WarningFSDUnion35 min
Aug 6, 1:06 AM CDTSevere Thunderstorm WarningFSDLincoln39 min
Aug 6, 1:36 AM CDTSevere Thunderstorm WarningFSDUnion24 min
Aug 5, 7:12 PM CDTSevere Thunderstorm WarningFSDMurray, Pipestone48 min
Aug 5, 7:53 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDMurray, Nobles, Pipestone, Rock41 min
Aug 5, 8:32 PM CDTSevere Thunderstorm WarningFSDNobles43 min
Aug 5, 9:31 PM CDTSevere Thunderstorm WarningFSDLyon, Sioux44 min

Nearby

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