Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 110, NWS Sioux Falls, SD

August 27, 20214 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Aug 27, 2021, 12:08 AM CDT for 4 counties in South Dakota. It was in force for 37 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 27, 2021, 12:08 AM CDT (05:08 UTC)
Expired
Aug 27, 2021, 12:45 AM CDT
In force
37 min
Issued by
NWS Sioux Falls, SD
Area
Storm-based polygon
Tornado
Possible
Damage threat
Considerable
Hail
0.75 in
Wind
70.0 mph

Counties Clay County, SD, Lincoln County, SD, Turner County, SD, Union County, SD

The radar

The Sioux Falls radar (KFSD), 55 km from the middle of the area, began a volume at 05:07 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 27, 12:18 AM CDTTSTM WND DMG2 Nnw Beresford, SDDELAYED REPORT - SOCIAL MEDIA REPORT INDICATES A BILLBOARD ON THE NORTHBOUND SIDE OF I-29 WAS BROKEN IN HALF BY STRONG WINDS.

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 26, 8:03 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 5.1 hours before the alert went out and 201 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, Omaha, NE at 00:00Z on 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5342 joules per kilogram.LCLLFCEL10008507005003002001001 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, Omaha, NE at 00:00Z on 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.193958Sfc1 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
5342 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
1163 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
199 m²/s²
Significant tornado parameter
3.8
Supercell composite
24.0

Open this sounding in Storm Lab

The text

As transmitted.

893 
WUUS53 KFSD 270508
SVRFSD
SDC027-083-125-127-270545-
/O.NEW.KFSD.SV.W.0110.210827T0508Z-210827T0545Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
1208 AM CDT Fri Aug 27 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northern Clay County in southeastern South Dakota...
  Southwestern Lincoln County in southeastern South Dakota...
  Southeastern Turner County in southeastern South Dakota...
  Northwestern Union County in southeastern South Dakota...

* Until 1245 AM CDT.

* At 1208 AM CDT, severe thunderstorms were located along a line
  extending from near Davis to near Centerville to 6 miles southeast
  of Wakonda, moving east at 35 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...
  Beresford around 1220 AM CDT.
  Union Grove State Park around 1225 AM CDT.

Other locations in the path of these severe thunderstorms include
Alcester.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4326 9664 4310 9657 4293 9667 4292 9714
      4304 9703 4319 9709
TIME...MOT...LOC 0508Z 260DEG 31KT 4318 9696 4306 9693 4296 9700 

TORNADO...POSSIBLE
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
752 
WWUS53 KFSD 270521
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
1221 AM CDT Fri Aug 27 2021

SDC125-270530-
/O.CAN.KFSD.SV.W.0110.000000T0000Z-210827T0545Z/
Turner SD-
1221 AM CDT Fri Aug 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN TURNER COUNTY IS
CANCELLED...

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

A Severe Thunderstorm Watch remains in effect until 300 AM CDT for
southeastern South Dakota.

LAT...LON 4326 9664 4310 9657 4293 9667 4292 9695
      4307 9691 4321 9693
TIME...MOT...LOC 0520Z 261DEG 33KT 4318 9681 4306 9676 4294 9684 

$$

SDC027-083-127-270545-
/O.CON.KFSD.SV.W.0110.000000T0000Z-210827T0545Z/
Clay SD-Lincoln SD-Union SD-
1221 AM CDT Fri Aug 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1245 AM CDT
FOR NORTHEASTERN CLAY...SOUTHWESTERN LINCOLN AND NORTHWESTERN UNION
COUNTIES...

At 1220 AM CDT, severe thunderstorms were located along a line
extending from 9 miles northeast of Centerville to Beresford to near
Union Grove State Park, moving east at 40 mph.

HAZARD...70 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
  Alcester.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4326 9664 4310 9657 4293 9667 4292 9695
      4307 9691 4321 9693
TIME...MOT...LOC 0520Z 261DEG 33KT 4318 9681 4306 9676 4294 9684 

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

$$

SG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 26, 11:05 PM CDTSevere Thunderstorm WarningFSDHutchinson, Turner, Yankton25 min
Aug 27, 12:17 AM CDTSevere Thunderstorm WarningFSDLincoln28 min
Aug 27, 12:34 AM CDTSevere Thunderstorm Warning Considerable damage threatFSDLincoln, Union41 min

Nearby

Severe 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.