Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 122, NWS Sioux Falls, SD

August 28, 2021Lincoln County, Minnehaha County, South Dakota; Lyon County, Sioux County, Iowa; Nobles County, Rock County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 28, 2021, 5:00 PM CDT for Lincoln County, Minnehaha County, South Dakota; Lyon County, Sioux County, Iowa; Nobles County, Rock County, Minnesota. It was in force for 45 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 28, 2021, 5:00 PM CDT (22:00 UTC)
Expired: Aug 28, 2021, 5:45 PM CDT
In force: 45 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Damage threat: Considerable
Hail: 1.5 in
Wind: 70.0 mph

Counties Lyon County, IA, Sioux County, IA, Nobles County, MN, Rock County, MN, Lincoln County, SD, Minnehaha County, SD

The radar

The Sioux Falls radar (KFSD), 38 km from the middle of the area, began a volume at 22:03 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 28, 5:28 PM CDT	HAIL 1	Larchwood, IA	PICTURE VIA SOCIAL MEDIA. RECEIVED LARGER HAIL FROM SECONDARY STORM LATER IN EVENING.

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.

Issued	Product	Office	Lasted
Aug 28, 3:57 PM CDT	Severe Thunderstorm Watch	SPC	7 hr
Aug 28, 3:44 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.0 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-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: 929 J/kg
Mixed-layer CIN: -277 J/kg
Mixed-layer LCL: 1419 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

331 
WUUS53 KFSD 282200
SVRFSD
IAC119-167-MNC105-133-SDC083-099-282245-
/O.NEW.KFSD.SV.W.0122.210828T2200Z-210828T2245Z/

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

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Lyon County in northwestern Iowa...
  Northern Sioux County in northwestern Iowa...
  Southern Rock County in southwestern Minnesota...
  Southwestern Nobles County in southwestern Minnesota...
  Southeastern Minnehaha County in southeastern South Dakota...
  Central Lincoln County in southeastern South Dakota...

* Until 545 PM CDT.

* At 500 PM CDT, severe thunderstorms were located along a line
  extending from near Lake Alvin State Recreation Area to near Newton
  Hills State Park, moving east at 40 mph.

  HAZARD...70 mph wind gusts and ping pong ball size hail.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings.

* Severe thunderstorms will be near...
  Larchwood around 510 PM CDT.
  Lester and Fairview around 515 PM CDT.
  Inwood around 520 PM CDT.
  Rock Rapids around 525 PM CDT.
  Rock Valley and Alvord around 530 PM CDT.
  Doon around 535 PM CDT.
  Hull and Ellsworth around 540 PM CDT.
  George and Boyden around 545 PM CDT.

Other locations impacted by these severe thunderstorms include Steen.

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 4352 9593 4315 9598 4323 9681 4347 9679
      4351 9659
TIME...MOT...LOC 2200Z 263DEG 37KT 4346 9653 4324 9669 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

APT

2 follow-up statements

142 
WWUS53 KFSD 282218
SVSFSD

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

IAC167-282228-
/O.CAN.KFSD.SV.W.0122.000000T0000Z-210828T2245Z/
Sioux IA-
518 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN SIOUX COUNTY 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.

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
northwestern Iowa...and southeastern South Dakota.

LAT...LON 4327 9596 4332 9660 4345 9668 4351 9659
      4352 9593
TIME...MOT...LOC 2218Z 265DEG 44KT 4348 9629 4333 9639 

$$

IAC119-MNC105-133-SDC083-099-282245-
/O.CON.KFSD.SV.W.0122.000000T0000Z-210828T2245Z/
Lyon IA-Rock MN-Nobles MN-Minnehaha SD-Lincoln SD-
518 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM CDT
FOR LYON...SOUTHERN ROCK...SOUTHWESTERN NOBLES...SOUTHEASTERN
MINNEHAHA AND NORTHEASTERN LINCOLN COUNTIES...

At 518 PM CDT, severe thunderstorms were located along a line
extending from near Lester to near Inwood, moving east at 50 mph.

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

These severe storms will be near...
  Rock Rapids around 530 PM CDT.
  Ellsworth around 535 PM CDT.
  George around 540 PM CDT.

Other locations impacted by these severe thunderstorms include Steen.

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 4327 9596 4332 9660 4345 9668 4351 9659
      4352 9593
TIME...MOT...LOC 2218Z 265DEG 44KT 4348 9629 4333 9639 

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

$$

APT

246 
WWUS53 KFSD 282241
SVSFSD

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

IAC119-MNC105-133-SDC083-099-282251-
/O.EXP.KFSD.SV.W.0122.000000T0000Z-210828T2245Z/
Lyon IA-Rock MN-Nobles MN-Minnehaha SD-Lincoln SD-
541 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR LYON...SOUTHERN ROCK...
SOUTHWESTERN NOBLES...SOUTHEASTERN MINNEHAHA AND NORTHEASTERN LINCOLN
COUNTIES WILL EXPIRE AT 545 PM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire. However gusty 
winds are still possible with these thunderstorms.

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

A Severe Thunderstorm Watch remains in effect until 900 PM CDT for
northwestern Iowa...and southeastern South Dakota.

LAT...LON 4327 9596 4332 9660 4345 9668 4351 9659
      4352 9593
TIME...MOT...LOC 2241Z 263DEG 37KT 4351 9598 4336 9608 

$$

APT

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 3:21 PM CDT	Severe Thunderstorm Warning	FSD	Lake, McCook, Miner, Minnehaha, Moody	24 min
Aug 28, 3:56 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Turner, Yankton	49 min
Aug 28, 4:23 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Lincoln, Turner	37 min
Aug 28, 4:23 PM CDT	Tornado Warning	FSD	Lincoln, Turner	37 min
Aug 28, 4:33 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	42 min
Aug 28, 4:39 PM CDT	Tornado Warning Tornado observed	FSD	Lincoln	36 min
Aug 28, 4:45 PM CDT	Tornado Warning	FSD	Lincoln, Minnehaha	30 min
Aug 28, 6:14 PM CDT	Severe Thunderstorm Warning	FSD	Hanson, Lake, McCook	31 min
Aug 28, 6:15 PM CDT	Severe Thunderstorm Warning	FSD	Minnehaha, Moody	45 min
Aug 28, 6:17 PM CDT	Severe Thunderstorm Warning	FSD	Hutchinson, McCook, Turner	43 min
Aug 28, 6:44 PM CDT	Severe Thunderstorm Warning	FSD	Davison, Hanson, Lake, McCook, Miner, Sanborn	46 min
Aug 28, 6:44 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	46 min
Aug 28, 6:48 PM CDT	Severe Thunderstorm Warning	FSD	Hanson, Lake, McCook, Minnehaha	42 min
Aug 28, 6:53 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	52 min
Aug 28, 5:26 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Lyon, Osceola	34 min
Aug 28, 5:29 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Lyon, Osceola	31 min
Aug 28, 5:34 PM CDT	Severe Thunderstorm Warning	FSD	Lyon	17 min
Aug 28, 4:49 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Nobles, Rock	41 min
Aug 28, 5:06 PM CDT	Tornado Warning	FSD	Murray, Nobles, Pipestone, Rock	24 min
Aug 28, 5:24 PM CDT	Tornado Warning	FSD	Nobles	36 min
Aug 28, 5:26 PM CDT	Tornado Warning	FSD	Cottonwood, Murray	34 min
Aug 28, 5:43 PM CDT	Tornado Warning	FSD	Cottonwood, Murray	32 min
Aug 28, 5:45 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Cottonwood, Jackson, Murray, Nobles	45 min
Aug 28, 5:49 PM CDT	Tornado Warning	FSD	Cottonwood, Jackson, Murray, Nobles	26 min
Aug 28, 6:01 PM CDT	Tornado Warning	FSD	Cottonwood	30 min

Nearby

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