Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 121, NWS Sioux Falls, SD

August 28, 2021Nobles County, Rock County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 28, 2021, 4:49 PM CDT for Nobles County, Rock County, Minnesota. It was in force for 41 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, 4:49 PM CDT (21:49 UTC)
Expired
Aug 28, 2021, 5:30 PM CDT
In force
41 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Possible
Damage threat
Considerable
Hail
1.0 in
Wind
70.0 mph

Counties Nobles County, MN, Rock County, MN

The radar

The Sioux Falls radar (KFSD), 48 km from the middle of the area, began a volume at 21:50 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, 4:57 PM CDTTSTM WND GST 681 Wsw Beaver Creek, MNDELAYED REPORT FROM BEAVER CREEK I-90 MP 4, MN. MN006.
Aug 28, 5:00 PM CDTTSTM WND GST 613 Wsw Luverne, MNDELAYED REPORT FROM MESONET STATION FW5856 LUVERNE.
Aug 28, 5:03 PM CDTTSTM WND GST 611 Wsw Luverne, MNDELAYED REPORT FROM PERSONAL WEATHER STATION JUST WEST OF LUVERNE, MN.
Aug 28, 5:23 PM CDTTSTM WND DMGAdrian, MNSTRONG WINDS KNOCKED TREES DOWN IN THE SOUTHERN PART OF ADRIAN.
Aug 28, 5:38 PM CDTHAIL 1Hills, MNDELAYED REPORT. MOST OF THE HAIL WAS DIMES OR SMALLER, BUT THERE WERE A FEW QUARTER-SIZED HAIL STONES.
Aug 28, 5:40 PM CDTTSTM WND DMGHills, MNDELAYED REPORT. TREES REPORTED DOWN, DIAMETER OF THE TRUNKS WAS 2-3 FEET. A POWER LINE WAS KNOCKED DOWN AS WELL, RESULTING IN POWER OUTAGE OF ABOUT 3 HOURS.

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

Aberdeen, SD (KABR), launched 12:00Z, 9.8 hours before the alert went out and 231 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 12:00Z on 2021-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Aberdeen, SD at 12:00Z on 2021-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 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
9 J/kg
Mixed-layer CIN
-334 J/kg
Mixed-layer LCL
1540 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
558 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

As transmitted.

469 
WUUS53 KFSD 282149
SVRFSD
MNC105-133-282230-
/O.NEW.KFSD.SV.W.0121.210828T2149Z-210828T2230Z/

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

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Rock County in southwestern Minnesota...
  Southwestern Nobles County in southwestern Minnesota...

* Until 530 PM CDT.

* At 448 PM CDT, a severe thunderstorm was located over Valley
  Springs, or 12 miles east of Sioux Falls, moving east at 40 mph.

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

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Hills and Beaver Creek around 500 PM CDT.
  Luverne around 510 PM CDT.
  Blue Mounds State Park around 515 PM CDT.
  Adrian and Lismore around 530 PM CDT.

Other locations impacted by this severe thunderstorm include Magnolia
and Steen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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 4350 9593 4350 9645 4373 9645 4375 9592
TIME...MOT...LOC 2148Z 262DEG 35KT 4360 9651 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

APT
1 follow-up statement
098 
WWUS53 KFSD 282205
SVSFSD

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

MNC105-133-282230-
/O.CON.KFSD.SV.W.0121.000000T0000Z-210828T2230Z/
Rock MN-Nobles MN-
505 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM CDT
FOR ROCK AND SOUTHWESTERN NOBLES COUNTIES...

At 503 PM CDT, a severe thunderstorm was located near Beaver Creek,
or near Luverne, moving east at 40 mph.

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

SOURCE...At 5:00 pm, law enforcement reports wind speed of 60 miles 
         per hour.

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

This severe storm will be near...
  Luverne around 510 PM CDT.
  Blue Mounds State Park around 515 PM CDT.
  Adrian and Lismore around 530 PM CDT.

Other locations impacted by this severe thunderstorm include Magnolia
and Steen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 4350 9593 4350 9645 4373 9645 4375 9592
TIME...MOT...LOC 2203Z 262DEG 35KT 4362 9630 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
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, 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, 5:29 PM CDTSevere Thunderstorm Warning Considerable damage threatFSDCottonwood, Jackson, Murray, Nobles, Pipestone, Rock31 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

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.