Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 162, NWS Sioux Falls, SD

September 17, 20218 counties in Minnesota; Minnehaha County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Sep 17, 2021, 12:34 AM CDT for 8 counties in Minnesota; Minnehaha County, South Dakota. It was in force for 56 min. 5 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
Sep 17, 2021, 12:34 AM CDT (05:34 UTC)
Expired
Sep 17, 2021, 1:30 AM CDT
In force
56 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Damage threat
Considerable
Hail
0.75 in
Wind
70.0 mph

Counties Cottonwood County, MN, Jackson County, MN, Lincoln County, MN, Lyon County, MN, Murray County, MN, Nobles County, MN, Pipestone County, MN, Rock County, MN, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 113 km from the middle of the area, began a volume at 05:34 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
Sep 17, 12:45 AM CDTTSTM WND DMG1 N Lake Wilson, MNSPOTTER REPORTED CROP DAMAGE, SEVERAL DOWNED LARGE BRANCHES, UPROOTED LARGE TREE. SENT PICTURES. TIME ESTIMATED WITH RADAR.
Sep 17, 12:47 AM CDTTSTM WND DMG5 Sse Woodstock, MNUPROOTED AND SNAPPED TREES. TIME ESTIMATED FROM RADAR.
Sep 17, 12:48 AM CDTTSTM WND DMG4 Sw Chandler, MNHOOP BARN DESTROYED. DOORS MISSING ON MACHINE SHED AND ROOF RIPPED OFF. TIME ESTIMATED FROM RADAR.
Sep 17, 12:52 AM CDTTSTM WND DMG2 E Lake Wilson, MNDAMAGED HOOP BARN. TIME ESTIMATED FROM RADAR.
Sep 17, 1:03 AM CDTTSTM WND GST 661 Wsw Slayton, MNAWOS STATION KDVP SLAYTON MUNICIPAL AIRPORT.

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, 5.6 hours before the alert went out and 238 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 2021-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -170 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1789 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
-170 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

216 
WUUS53 KFSD 170534
SVRFSD
MNC033-063-081-083-101-105-117-133-SDC099-170630-
/O.NEW.KFSD.SV.W.0162.210917T0534Z-210917T0630Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1234 AM CDT Fri Sep 17 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Lyon County in southwestern Minnesota...
  Eastern Lincoln County in southwestern Minnesota...
  Northern Rock County in southwestern Minnesota...
  Northern Jackson County in southwestern Minnesota...
  Northern Nobles County in southwestern Minnesota...
  Murray County in southwestern Minnesota...
  Cottonwood County in southwestern Minnesota...
  Pipestone County in southwestern Minnesota...
  Northeastern Minnehaha County in southeastern South Dakota...

* Until 130 AM CDT.

* At 1234 AM CDT, severe thunderstorms were located along a line
  extending from near Porter to near Holland to Jasper, moving east
  at 65 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Ruthton and Woodstock around 1240 AM CDT.
  Minneota, Edgerton and Taunton around 1245 AM CDT.
  Ghent, Lake Wilson and Current Lake around 1250 AM CDT.

Other locations in the path of these severe thunderstorms include
Slayton, Leota, Chandler, Cottonwood, Currie, Lake Shetek State Park,
Dovray, Fulda, Westbrook and Storden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4419 9559 4419 9511 4411 9510 4410 9486
      4380 9486 4378 9650 4409 9630 4463 9629
      4463 9561
TIME...MOT...LOC 0534Z 269DEG 56KT 4460 9624 4410 9625 4385 9640 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

SG
1 follow-up statement
810 
WWUS53 KFSD 170602
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
102 AM CDT Fri Sep 17 2021

MNC081-117-133-SDC099-170612-
/O.CAN.KFSD.SV.W.0162.000000T0000Z-210917T0630Z/
Lincoln MN-Rock MN-Pipestone MN-Minnehaha SD-
102 AM CDT Fri Sep 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN LINCOLN...NORTHERN
ROCK...PIPESTONE AND NORTHEASTERN MINNEHAHA COUNTIES IS CANCELLED...

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

LAT...LON 4419 9559 4419 9511 4411 9510 4410 9486
      4380 9486 4380 9605 4405 9603 4462 9600
      4463 9561
TIME...MOT...LOC 0602Z 269DEG 56KT 4461 9567 4411 9569 4386 9584 

$$

MNC033-063-083-101-105-170630-
/O.CON.KFSD.SV.W.0162.000000T0000Z-210917T0630Z/
Lyon MN-Jackson MN-Nobles MN-Murray MN-Cottonwood MN-
102 AM CDT Fri Sep 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 AM CDT
FOR LYON...NORTHERN JACKSON...NORTHERN NOBLES...MURRAY AND COTTONWOOD
COUNTIES...

At 102 AM CDT, severe thunderstorms were located along a line
extending from Cottonwood to Lake Shetek State Park to 6 miles north
of Wilmont, moving east at 65 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  Dovray, Fulda, Westbrook, Storden, Heron Lake, Jeffers, Windom, 
  Bingham Lake and Mountain Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4419 9559 4419 9511 4411 9510 4410 9486
      4380 9486 4380 9605 4405 9603 4462 9600
      4463 9561
TIME...MOT...LOC 0602Z 269DEG 56KT 4461 9567 4411 9569 4386 9584 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 17, 12:10 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDLincoln, Pipestone, Rock35 min
Sep 17, 12:36 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDJackson, Nobles, Rock54 min
Sep 17, 1:21 AM CDTSevere Thunderstorm WarningFSDCottonwood, Jackson, Lyon, Murray, Nobles39 min
Sep 17, 1:23 AM CDTSevere Thunderstorm WarningFSDJackson, Nobles67 min
Sep 16, 10:20 PM CDTSevere Thunderstorm WarningFSDCharles Mix, Gregory25 min
Sep 16, 11:31 PM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix, Hutchinson, Yankton29 min
Sep 17, 12:29 AM CDTSevere Thunderstorm WarningFSDClay, Lincoln, Turner, Union, Yankton46 min
Sep 17, 1:11 AM CDTSevere Thunderstorm WarningFSDUnion49 min

Nearby

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