Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 86, NWS Sioux Falls, SD

August 8, 2021Nobles County, Minnesota; Osceola County, Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 8, 2021, 4:10 PM CDT for Nobles County, Minnesota; Osceola County, Iowa. It was in force for 50 min. 1 report 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 8, 2021, 4:10 PM CDT (21:10 UTC)
Expired: Aug 8, 2021, 5:00 PM CDT
In force: 50 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Tornado: Possible
Hail: 1.0 in
Wind: 60.0 mph

Counties Osceola County, IA, Nobles County, MN

The radar

The Sioux Falls radar (KFSD), 99 km from the middle of the area, began a volume at 21:12 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

Time	Report	Where	Remark
Aug 8, 4:52 PM CDT	TORNADO	2 Sse Ocheyedan, IA	DAMAGE TO THE ROOF OF A CHICKEN BARN.

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, 9.2 hours before the alert went out and 217 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1659 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 542 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 24 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

As transmitted.

082 
WUUS53 KFSD 082110
SVRFSD
IAC143-MNC105-082200-
/O.NEW.KFSD.SV.W.0086.210808T2110Z-210808T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
410 PM CDT Sun Aug 8 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Eastern Osceola County in northwestern Iowa...
  Southeastern Nobles County in southwestern Minnesota...

* Until 500 PM CDT.

* At 410 PM CDT, a severe thunderstorm was located near Worthington,
  moving southeast at 20 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.

* This severe thunderstorm will be near...
  Round Lake around 420 PM CDT.

Other locations in the path of this severe thunderstorm include
Ocheyedan and Harris.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4330 9565 4358 9575 4364 9552 4355 9545
      4350 9545 4350 9542 4345 9538 4336 9539
TIME...MOT...LOC 2110Z 331DEG 19KT 4355 9564 

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

$$

Kalin

2 follow-up statements

774 
WWUS53 KFSD 082137
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
437 PM CDT Sun Aug 8 2021

IAC143-MNC105-082200-
/O.CON.KFSD.SV.W.0086.000000T0000Z-210808T2200Z/
Osceola IA-Nobles MN-
437 PM CDT Sun Aug 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR EASTERN OSCEOLA AND SOUTHEASTERN NOBLES COUNTIES...

At 436 PM CDT, a severe thunderstorm was located over Ocheyedan, or
10 miles east of Sibley, moving southeast at 20 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...
  Ocheyedan and Harris.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4348 9568 4354 9546 4353 9545 4350 9545
      4350 9542 4346 9539 4345 9538 4336 9539
      4330 9563
TIME...MOT...LOC 2136Z 327DEG 16KT 4344 9555 

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

$$

Kalin

832 
WWUS53 KFSD 082146
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
446 PM CDT Sun Aug 8 2021

MNC105-082155-
/O.CAN.KFSD.SV.W.0086.000000T0000Z-210808T2200Z/
Nobles MN-
446 PM CDT Sun Aug 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN NOBLES COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4347 9561 4350 9542 4346 9539 4345 9538
      4336 9539 4330 9563
TIME...MOT...LOC 2145Z 331DEG 19KT 4339 9551 

$$

IAC143-082200-
/O.CON.KFSD.SV.W.0086.000000T0000Z-210808T2200Z/
Osceola IA-
446 PM CDT Sun Aug 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM CDT
FOR EASTERN OSCEOLA COUNTY...

At 445 PM CDT, a severe thunderstorm was located over Ocheyedan, or
11 miles east of Sibley, moving southeast 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.

Locations impacted include...
Ocheyedan and Harris. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4347 9561 4350 9542 4346 9539 4345 9538
      4336 9539 4330 9563
TIME...MOT...LOC 2145Z 331DEG 19KT 4339 9551 

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

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 8, 4:29 PM CDT	Tornado Warning	FSD	Nobles	31 min
Aug 8, 4:50 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Clay, Dickinson, O'Brien, Osceola	55 min
Aug 8, 5:26 PM CDT	Tornado Warning	FSD	Clay, Dickinson, O'Brien	49 min
Aug 8, 6:31 PM CDT	Tornado Warning Tornado observed	FSD	Buena Vista, Clay	44 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2021 Severe Thunderstorm Warnings in Iowa, 2021 Every 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.