Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 124, NWS Sioux Falls, SD

August 28, 20216 counties in Minnesota; Lyon County, Osceola County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 28, 2021, 5:29 PM CDT for 6 counties in Minnesota; Lyon County, Osceola County, Iowa. It was in force for 31 min. 6 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, 5:29 PM CDT (22:29 UTC)
Expired
Aug 28, 2021, 6:00 PM CDT
In force
31 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Possible
Damage threat
Considerable
Hail
1.25 in
Wind
70.0 mph

Counties Lyon County, IA, Osceola County, IA, Cottonwood County, MN, Jackson County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN

The radar

The Sioux Falls radar (KFSD), 77 km from the middle of the area, began a volume at 22:30 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, 5:30 PM CDTTSTM WND DMG2 E Iona, MNTREES SNAPPED BY WINDS.
Aug 28, 5:36 PM CDTTSTM WND DMGAvoca, MNMACHINE SHED DAMAGED.
Aug 28, 5:44 PM CDTTSTM WND GST 601 W Slayton, MN
Aug 28, 5:45 PM CDTTSTM WND DMGAvoca, MNREPORT VIA SOCIAL MEDIA OF HEAVY TREE DAMAGE IN AVOCA.
Aug 28, 5:45 PM CDTTSTM WND GST 55Worthington, MNWALL CLOUD PUSHED ACROSS TOWN, SWITCHING WINDS FROM NEARLY CALM TO GUSTY AT 44 TO 55 MPH.
Aug 28, 5:58 PM CDTTSTM WND DMG1 E Slayton, MNREPORT VIA SOCIAL MEDIA OF TREE DAMAGE EAST OF SLAYTON.

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 12:00Z, 10.5 hours before the alert went out and 212 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 2021-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1550 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 2021-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 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
1550 J/kg
Mixed-layer CIN
-130 J/kg
Mixed-layer LCL
676 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.3

Open this sounding in Storm Lab

The text

As transmitted.

008 
WUUS53 KFSD 282229
SVRFSD
IAC119-143-MNC033-063-101-105-117-133-282300-
/O.NEW.KFSD.SV.W.0124.210828T2229Z-210828T2300Z/

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

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northeastern Lyon County in northwestern Iowa...
  Northern Osceola County in northwestern Iowa...
  Eastern Rock County in southwestern Minnesota...
  Southwestern Jackson County in southwestern Minnesota...
  Nobles County in southwestern Minnesota...
  Southern Murray County in southwestern Minnesota...
  Southwestern Cottonwood County in southwestern Minnesota...
  Southeastern Pipestone County in southwestern Minnesota...

* Until 600 PM CDT.

* At 528 PM CDT, severe thunderstorms were located along a line
  extending from near Chandler to Wilmont to near Little Rock, moving
  east at 55 mph.

  HAZARD...70 mph wind gusts and half dollar size hail.

  SOURCE...At 5:15 pm, a weather instrument measured a wind gust of 
           61 miles per hour 2 miles southwest of Luvurne.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Severe thunderstorms will be near...
  Slayton around 535 PM CDT.
  Worthington and Fulda around 545 PM CDT.
  Brewster and Round Lake around 550 PM CDT.

Other locations impacted by these severe thunderstorms include
Kenneth, Avoca, Hadley, Kinbrae, Dundee, Iona, Magnolia and Bigelow.

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 4404 9545 4344 9545 4342 9622 4375 9615
      4400 9615
TIME...MOT...LOC 2228Z 264DEG 47KT 4396 9590 4375 9586 4353 9588 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...OBSERVED
MAX WIND GUST...70 MPH

$$

APT
1 follow-up statement
541 
WWUS53 KFSD 282248
SVSFSD

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

IAC119-143-MNC117-133-282258-
/O.CAN.KFSD.SV.W.0124.000000T0000Z-210828T2300Z/
Lyon IA-Osceola IA-Rock MN-Pipestone MN-
548 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LYON...NORTHERN
OSCEOLA...EASTERN ROCK AND SOUTHEASTERN PIPESTONE COUNTIES IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

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

LAT...LON 4404 9545 4351 9545 4353 9593 4374 9602
      4401 9601
TIME...MOT...LOC 2248Z 264DEG 47KT 4398 9557 4377 9553 4355 9555 

$$

MNC033-063-101-105-282300-
/O.CON.KFSD.SV.W.0124.000000T0000Z-210828T2300Z/
Jackson MN-Nobles MN-Murray MN-Cottonwood MN-
548 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR WEST CENTRAL JACKSON...NOBLES...SOUTHERN MURRAY AND SOUTHWESTERN
COTTONWOOD COUNTIES...

At 548 PM CDT, severe thunderstorms were located along a line
extending from near Dovray to 6 miles northwest of Brewster to near
Round Lake, moving east at 55 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

These severe thunderstorms will remain over mainly rural areas of
west central Jackson, Nobles, southern Murray and southwestern
Cottonwood Counties, including the following locations... Kinbrae,
Dundee, Avoca, Iona and Hadley.

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 4404 9545 4351 9545 4353 9593 4374 9602
      4401 9601
TIME...MOT...LOC 2248Z 264DEG 47KT 4398 9557 4377 9553 4355 9555 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

APT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 4:45 PM CDTTornado WarningFSDRock30 min
Aug 28, 4:49 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDNobles, Rock41 min
Aug 28, 5:00 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDNobles, Rock45 min
Aug 28, 5:06 PM CDTTornado WarningFSDMurray, Nobles, Pipestone, Rock24 min
Aug 28, 5:24 PM CDTTornado WarningFSDNobles36 min
Aug 28, 5:26 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDCottonwood, Jackson, Murray, Nobles, Pipestone, Rock34 min
Aug 28, 5:26 PM CDTTornado WarningFSDCottonwood, Murray34 min
Aug 28, 5:34 PM CDTSevere Thunderstorm WarningFSDRock17 min
Aug 28, 5:43 PM CDTTornado WarningFSDCottonwood, Murray32 min
Aug 28, 5:45 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDCottonwood, Jackson, Murray, Nobles45 min
Aug 28, 5:49 PM CDTTornado WarningFSDCottonwood, Jackson, Murray, Nobles26 min
Aug 28, 6:01 PM CDTTornado WarningFSDCottonwood30 min
Aug 28, 6:15 PM CDTSevere Thunderstorm WarningFSDPipestone, Rock45 min
Aug 28, 6:53 PM CDTSevere Thunderstorm WarningFSDRock52 min
Aug 28, 4:23 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDLyon, Sioux37 min
Aug 28, 4:39 PM CDTTornado Warning Tornado observedFSDLyon36 min
Aug 28, 6:44 PM CDTSevere Thunderstorm WarningFSDLyon46 min

Nearby

Severe 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.