Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 139, NWS Sioux Falls, SD

August 28, 20215 counties in South Dakota; Rock County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 28, 2021, 7:48 PM CDT for 5 counties in South Dakota; Rock County, Minnesota. It was in force for 31 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, 7:48 PM CDT (00:48 UTC)
Expired: Aug 28, 2021, 8:19 PM CDT
In force: 31 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Rock County, MN, Lake County, SD, McCook County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD

The radar

The Sioux Falls radar (KFSD), 24 km from the middle of the area, began a volume at 00:48 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, 7:50 PM CDT	HAIL 1.5	5 E Canistota, SD	REPORT VIA SOCIAL MEDIA FROM LAKE VERMILLION.

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

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 0.8 hours before the alert went out and 183 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: 143 J/kg
Mixed-layer CIN: -122 J/kg
Mixed-layer LCL: 1242 m above ground
0-6 km bulk shear: 71 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: 268 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted.

866 
WUUS53 KFSD 290048
SVRFSD
MNC133-SDC079-087-099-101-125-290130-
/O.NEW.KFSD.SV.W.0139.210829T0048Z-210829T0130Z/

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

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northwestern Rock County in southwestern Minnesota...
  Southwestern Moody County in east central South Dakota...
  Southeastern Lake County in east central South Dakota...
  Minnehaha County in southeastern South Dakota...
  Southeastern McCook County in southeastern South Dakota...
  North central Turner County in southeastern South Dakota...

* Until 830 PM CDT.

* At 748 PM CDT, a severe thunderstorm was located over Lake
  Vermillion State Recreation Area, moving northeast at 50 mph.

  HAZARD...60 mph wind gusts and half dollar 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...
  Hartford around 800 PM CDT.
  Crooks around 805 PM CDT.
  Colton around 810 PM CDT.
  Baltic around 815 PM CDT.
  Dell Rapids around 820 PM CDT.
  Trent around 825 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota...and east central South Dakota.

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...and east central South Dakota.

&&

LAT...LON 4389 9645 4385 9646 4385 9640 4379 9633
      4344 9720 4357 9743 4414 9676
TIME...MOT...LOC 0048Z 234DEG 46KT 4360 9716 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SG

2 follow-up statements

747 
WWUS53 KFSD 290100
SVSFSD

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

MNC133-SDC079-087-099-101-125-290130-
/O.CON.KFSD.SV.W.0139.000000T0000Z-210829T0130Z/
Rock MN-Moody SD-Lake SD-Minnehaha SD-McCook SD-Turner SD-
800 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM CDT
FOR NORTHWESTERN ROCK...SOUTHWESTERN MOODY...SOUTHEASTERN LAKE...
MINNEHAHA...SOUTHEASTERN MCCOOK AND NORTH CENTRAL TURNER COUNTIES...

At 800 PM CDT, a severe thunderstorm was located near Humboldt, or 9
miles northeast of Lake Vermillion State Recreation Area, moving
northeast at 50 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Trained weather spotters. At 755 PM quarter sized hail was 
         reported near Humboldt.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
  Crooks, Colton, Dell Rapids, Baltic, Trent and Egan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota...and east central South Dakota.

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

&&

LAT...LON 4389 9645 4385 9646 4385 9640 4379 9633
      4344 9720 4357 9743 4414 9676
TIME...MOT...LOC 0100Z 233DEG 44KT 4368 9702 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SG

272 
WWUS53 KFSD 290119
SVSFSD

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

MNC133-SDC079-087-099-101-125-290128-
/O.CAN.KFSD.SV.W.0139.000000T0000Z-210829T0130Z/
Rock MN-Moody SD-Lake SD-Minnehaha SD-McCook SD-Turner SD-
819 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ROCK...
SOUTHWESTERN MOODY...SOUTHEASTERN LAKE...MINNEHAHA...SOUTHEASTERN
MCCOOK AND NORTH CENTRAL TURNER COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with this thunderstorm.

A Tornado Watch remains in effect until 900 PM CDT for southwestern
Minnesota...and east central South Dakota.

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

Remember, a Severe Thunderstorm Warning still remains in effect for
southern Turner county until 830 PM CDT. 

LAT...LON 4389 9645 4385 9646 4385 9640 4379 9633
      4344 9720 4357 9743 4414 9676
TIME...MOT...LOC 0116Z 234DEG 46KT 4382 9676 

$$

SG

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 7:23 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Lincoln	52 min
Aug 28, 7:25 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Hanson, Lake, McCook, Miner, Minnehaha, Moody	50 min
Aug 28, 7:27 PM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Hutchinson, Turner, Yankton	48 min
Aug 28, 7:50 PM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Clay, Hutchinson, Lincoln, Turner, Yankton	40 min
Aug 28, 8:52 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Minnehaha	23 min
Aug 28, 9:13 PM CDT	Severe Thunderstorm Warning	FSD	Lincoln	47 min
Aug 28, 9:20 PM CDT	Flash Flood Warning	FSD	Lincoln, Minnehaha	85 min
Aug 28, 9:29 PM CDT	Flash Flood Warning	FSD	Lincoln, Minnehaha	3 hr
Aug 28, 10:36 PM CDT	Flash Flood Warning	FSD	Lincoln, Minnehaha	114 min
Aug 28, 11:46 PM CDT	River Flood Warning	FSD	Lincoln, Minnehaha	8 hr
Aug 29, 7:44 AM CDT	River Flood Warning	FSD	Lincoln	15 hr
Aug 28, 7:00 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Lincoln, Lyon, Murray, Pipestone	45 min
Aug 28, 7:34 PM CDT	Severe Thunderstorm Warning	FSD	Lyon, Murray, Pipestone	56 min
Aug 28, 8:03 PM CDT	Flash Flood Warning	FSD	Murray, Pipestone	6 hr
Aug 28, 8:06 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Nobles, Rock	54 min
Aug 28, 8:17 PM CDT	Severe Thunderstorm Warning Considerable damage threat	FSD	Cottonwood, Lyon, Murray	58 min
Aug 28, 10:04 PM CDT	Flash Flood Warning	FSD	Cottonwood, Jackson, Murray, Nobles	4 hr
Aug 28, 10:24 PM CDT	Flash Flood Warning	FSD	Cottonwood, Jackson	5 hr

Nearby

Severe Thunderstorm Warnings in South Dakota, 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.