Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 57, NWS Sioux Falls, SD

July 9, 20214 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 9, 2021, 1:22 AM CDT for 4 counties in South Dakota. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 9, 2021, 1:22 AM CDT (06:22 UTC)
Expired: Jul 9, 2021, 2:00 AM CDT
In force: 38 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.25 in
Wind: 50.0 mph

Counties Aurora County, SD, Davison County, SD, Jerauld County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 134 km from the middle of the area, began a volume at 06:22 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 8, 9:33 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 6.4 hours before the alert went out and 113 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: 82 J/kg
Mixed-layer CIN: -125 J/kg
Mixed-layer LCL: 996 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 133 m²/s²
0-3 km storm-relative helicity: 211 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted.

373 
WUUS53 KFSD 090622
SVRFSD
SDC003-035-073-111-090700-
/O.NEW.KFSD.SV.W.0057.210709T0622Z-210709T0700Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
122 AM CDT Fri Jul 9 2021

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Northwestern Davison County in southeastern South Dakota...
  Southwestern Sanborn County in east central South Dakota...
  Northeastern Aurora County in south central South Dakota...
  Southeastern Jerauld County in central South Dakota...

* Until 200 AM CDT.

* At 122 AM CDT, a severe thunderstorm was located near Storla, or 17
  miles north of Plankinton, moving southeast at 30 mph.

  HAZARD...Half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will be near...
  Storla around 135 AM CDT.
  Letcher around 150 AM CDT.
  Loomis around 200 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4392 9854 4404 9839 4388 9797 4365 9832
TIME...MOT...LOC 0622Z 308DEG 26KT 4396 9840 

HAIL...1.25IN
WIND...<50MPH
 
$$

SSC

2 follow-up statements

755 
WWUS53 KFSD 090646
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
146 AM CDT Fri Jul 9 2021

SDC073-090656-
/O.CAN.KFSD.SV.W.0057.000000T0000Z-210709T0700Z/
Jerauld SD-
146 AM CDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN JERAULD 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 4388 9836 4397 9822 4388 9797 4365 9832
TIME...MOT...LOC 0646Z 308DEG 26KT 4385 9821 

$$

SDC003-035-111-090700-
/O.CON.KFSD.SV.W.0057.000000T0000Z-210709T0700Z/
Davison SD-Sanborn SD-Aurora SD-
146 AM CDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 AM CDT
FOR NORTHWESTERN DAVISON...SOUTHWESTERN SANBORN AND EAST CENTRAL
AURORA COUNTIES...

At 146 AM CDT, Doppler radar indicated a severe thunderstorm capable
of producing quarter size hail. This storm was located near Letcher,
or 11 miles northwest of Mitchell, moving southeast at 30 mph.

This severe storm will be near...
  Loomis around 200 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you are in the path of this storm, prepare immediately for large
hail and damaging winds. People outside should move to a shelter,
preferably inside a strong building and away from windows.

In addition to large hail and damaging winds, continuous cloud to
ground lightning is occurring with this storm.  Move indoors
immediately. Lightning is one of nature's leading killers. Remember,
if you can hear thunder, you are close enough to be struck by
lightning.

&&

LAT...LON 4388 9836 4397 9822 4388 9797 4365 9832
TIME...MOT...LOC 0646Z 308DEG 26KT 4385 9821 

$$

SSC

185 
WWUS53 KFSD 090652
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
152 AM CDT Fri Jul 9 2021

SDC003-035-111-090701-
/O.EXP.KFSD.SV.W.0057.000000T0000Z-210709T0700Z/
Davison SD-Sanborn SD-Aurora SD-
152 AM CDT Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN DAVISON...
SOUTHWESTERN SANBORN AND EAST CENTRAL AURORA COUNTIES WILL EXPIRE AT
200 AM CDT...
                
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 will be allowed to expire. However heavy rain
is still possible with this thunderstorm.

LAT...LON 4388 9836 4397 9822 4388 9797 4365 9832
TIME...MOT...LOC 0651Z 308DEG 26KT 4383 9818 

$$

SSC

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 10:53 PM CDT	Severe Thunderstorm Warning	FSD	Bon Homme, Hutchinson, Turner, Yankton	52 min
Jul 8, 10:56 PM CDT	Severe Thunderstorm Warning	FSD	Yankton	19 min
Jul 8, 11:11 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Yankton	34 min
Jul 8, 11:21 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Hutchinson, Lincoln, Turner, Yankton	39 min
Jul 8, 11:50 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Union	40 min
Jul 8, 11:59 PM CDT	Severe Thunderstorm Warning	FSD	Clay, Lincoln, Turner, Union	46 min
Jul 9, 12:44 AM CDT	Severe Thunderstorm Warning	FSD	Clay, Union	46 min
Jul 9, 12:46 AM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Union	44 min
Jul 9, 2:15 AM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Union	45 min
Jul 9, 2:34 AM CDT	Severe Thunderstorm Warning	FSD	Hanson, Lake, McCook, Miner	41 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.