Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 142, NWS Sioux Falls, SD

August 28, 2021Cottonwood County, Lyon County, Murray County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 28, 2021, 8:17 PM CDT for Cottonwood County, Lyon County, Murray County, Minnesota. It was in force for 58 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 28, 2021, 8:17 PM CDT (01:17 UTC)
Expired
Aug 28, 2021, 9:15 PM CDT
In force
58 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Possible
Damage threat
Considerable
Hail
1.75 in
Wind
60.0 mph

Counties Cottonwood County, MN, Lyon County, MN, Murray County, MN

The radar

The Sioux Falls radar (KFSD), 121 km from the middle of the area, began a volume at 01:21 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 28, 8:21 PM CDTHAIL 1.754 N Currie, MNLOTS OF GOLF BALL SIZED HAIL AND HEAVY RAINFALL 3.40 INCHES SO FAR.
Aug 28, 8:39 PM CDTTSTM WND GST 593 W Dovray, MNDELAYED REPORT FROM MESONET STATION MN038 DOVRAY MN-30 MILE POST 49.

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 28, 3:44 PM CDTTornado WatchSPC5 hr
Aug 28, 3:57 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.3 hours before the alert went out and 165 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, Minneapolis, MN at 00:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1990 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, Minneapolis, MN at 00:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 252 square meters per square second.19395878Sfc1 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
1990 J/kg
Mixed-layer CIN
-120 J/kg
Mixed-layer LCL
977 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.0

Open this sounding in Storm Lab

The text

As transmitted.

172 
WUUS53 KFSD 290117
SVRFSD
MNC033-083-101-290215-
/O.NEW.KFSD.SV.W.0142.210829T0117Z-210829T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
817 PM CDT Sat Aug 28 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Southeastern Lyon County in southwestern Minnesota...
  Northeastern Murray County in southwestern Minnesota...
  Northwestern Cottonwood County in southwestern Minnesota...

* Until 915 PM CDT.

* At 816 PM CDT, a severe thunderstorm was located near Lake Shetek 
  State Park, or 10 miles northeast of Slayton, moving northeast at 
  20 mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Dovray around 825 PM CDT.
  Tracy around 835 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota.

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

A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota.

&&

LAT...LON 4398 9572 4424 9583 4431 9559 4419 9559
      4419 9511 4411 9510 4411 9506 4404 9503
TIME...MOT...LOC 0116Z 243DEG 18KT 4413 9565 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Kalin
2 follow-up statements
496 
WWUS53 KFSD 290122
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
822 PM CDT Sat Aug 28 2021

MNC033-083-101-290215-
/O.CON.KFSD.SV.W.0142.000000T0000Z-210829T0215Z/
Lyon MN-Murray MN-Cottonwood MN-
822 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT
FOR SOUTHEASTERN LYON...NORTHEASTERN MURRAY AND NORTHWESTERN
COTTONWOOD COUNTIES...

At 822 PM CDT, a severe thunderstorm was located near Lake Shetek
State Park, or 12 miles northeast of Slayton, moving northeast at 20
mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Trained weather spotters reported golf ball size hail 4 
         miles north of Currie at 820 pm.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

This severe storm will be near...
  Tracy around 830 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota.

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

&&

LAT...LON 4398 9572 4424 9583 4431 9559 4419 9559
      4419 9511 4411 9510 4411 9506 4404 9503
TIME...MOT...LOC 0122Z 243DEG 18KT 4414 9561 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Kalin
181 
WWUS53 KFSD 290209
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
909 PM CDT Sat Aug 28 2021

MNC033-083-101-290218-
/O.EXP.KFSD.SV.W.0142.000000T0000Z-210829T0215Z/
Lyon MN-Murray MN-Cottonwood MN-
909 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LYON...
NORTHEASTERN MURRAY AND NORTHWESTERN COTTONWOOD COUNTIES WILL EXPIRE
AT 915 PM 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 and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
southwestern Minnesota.

LAT...LON 4398 9572 4424 9583 4431 9559 4419 9559
      4419 9511 4411 9510 4411 9506 4404 9503
TIME...MOT...LOC 0208Z 243DEG 18KT 4424 9533 

$$

Kalin

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 7:00 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDLincoln, Lyon, Murray, Pipestone45 min
Aug 28, 7:23 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDRock52 min
Aug 28, 7:34 PM CDTSevere Thunderstorm WarningFSDLyon, Murray, Pipestone56 min
Aug 28, 7:48 PM CDTSevere Thunderstorm WarningFSDRock31 min
Aug 28, 8:03 PM CDTFlash Flood WarningFSDMurray, Pipestone6 hr
Aug 28, 8:06 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDNobles, Rock54 min
Aug 28, 8:52 PM CDTSevere Thunderstorm WarningFSDMurray, Nobles, Rock23 min
Aug 28, 9:13 PM CDTSevere Thunderstorm WarningFSDJackson, Nobles, Rock47 min
Aug 28, 9:29 PM CDTFlash Flood WarningFSDMurray, Nobles, Pipestone, Rock3 hr
Aug 28, 10:04 PM CDTFlash Flood WarningFSDCottonwood, Jackson, Murray, Nobles4 hr
Aug 28, 10:24 PM CDTFlash Flood WarningFSDCottonwood, Jackson5 hr

Nearby

Severe Thunderstorm Warnings in Minnesota, 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.