Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 99, NWS Sioux Falls, SD

August 24, 2021Cottonwood County, Murray County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 24, 2021, 8:16 AM CDT for Cottonwood County, Murray County, Minnesota. It was in force for 44 min. 3 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 24, 2021, 8:16 AM CDT (13:16 UTC)
Expired
Aug 24, 2021, 9:00 AM CDT
In force
44 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Cottonwood County, MN, Murray County, MN

The radar

The Sioux Falls radar (KFSD), 109 km from the middle of the area, began a volume at 13:17 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 24, 8:32 AM CDTHAIL 1Avoca, MNCORRECTS PREVIOUS HAIL REPORT FROM AVOCA. HE SAID IT HAD BEEN HAILING ABOUT 7 MINUTES AND IT WAS STARTING TO LET UP.
Aug 24, 8:42 AM CDTHAIL 1Avoca, MNHE SAID IT HAD BEEN HAILING ABOUT 7 MINUTES AND IT WAS STARTING TO LET UP.
Aug 24, 9:05 AM CDTHAIL 16 S Westbrook, MNCORRECTS PREVIOUS HAIL REPORT FROM 6 S WESTBROOK. SAID HE WAS AT THE INTERSECTION OF COUNTY ROAD 7 AND COUNTY ROAD 13 AND IT WAS ACTIVELY HAILING DIME TO QUARTERS. HE CALLED AT 0915 ON 24AUG.

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 1.3 hours before the alert went out and 177 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 12:00Z on 2021-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1192 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 12:00Z on 2021-08-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 141 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
1192 J/kg
Mixed-layer CIN
-180 J/kg
Mixed-layer LCL
1234 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
178 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.9

Open this sounding in Storm Lab

The text

As transmitted.

183 
WUUS53 KFSD 241316
SVRFSD
MNC033-101-241400-
/O.NEW.KFSD.SV.W.0099.210824T1316Z-210824T1400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
816 AM CDT Tue Aug 24 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Murray County in southwestern Minnesota...
  Western Cottonwood County in southwestern Minnesota...

* Until 900 AM CDT.

* At 815 AM CDT, severe thunderstorms were located along a line
  extending from near Walnut Grove to near Dovray to Slayton, moving
  east at 35 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.

* Locations impacted include...
  Slayton, Fulda, Westbrook, Jeffers, Chandler, Currie, Storden,
  Dovray, Lake Shetek State Park, Avoca, Iona and Hadley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4386 9537 4386 9602 4402 9591 4420 9564
      4419 9511 4411 9510
TIME...MOT...LOC 1315Z 249DEG 32KT 4419 9555 4410 9559 4397 9577 

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

$$

BP
1 follow-up statement
917 
WWUS53 KFSD 241351
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
851 AM CDT Tue Aug 24 2021

MNC033-101-241400-
/O.CON.KFSD.SV.W.0099.000000T0000Z-210824T1400Z/
Murray MN-Cottonwood MN-
851 AM CDT Tue Aug 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 AM CDT
FOR SOUTHERN MURRAY AND WESTERN COTTONWOOD COUNTIES...

At 851 AM CDT, severe thunderstorms were located along a line
extending from 6 miles east of Lamberton to near Jeffers to near
Westbrook, moving east at 35 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...A trained weather spotter reported quarter sized hail in 
         Avoca MN.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Slayton, Fulda, Westbrook, Jeffers, Chandler, Currie, Storden,
Dovray, Avoca, Iona and Hadley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4386 9537 4386 9602 4402 9584 4408 9565
      4420 9544 4419 9511 4411 9510
TIME...MOT...LOC 1351Z 249DEG 32KT 4421 9514 4410 9524 4398 9549 

HAIL THREAT...OBSERVED
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.

IssuedProductOfficeCountiesLasted
Aug 24, 8:59 AM CDTSevere Thunderstorm WarningFSDCottonwood, Murray61 min
Aug 24, 9:43 AM CDTSevere Thunderstorm WarningFSDNobles47 min
Aug 24, 10:00 AM CDTSevere Thunderstorm WarningFSDCottonwood, Jackson, Nobles, Rock45 min
Aug 24, 10:44 AM CDTSevere Thunderstorm WarningFSDJackson, Nobles30 min

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.