Alert archive / South Dakota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 59, NWS Sioux Falls, SD

July 9, 20214 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 9, 2021, 2:34 AM CDT for 4 counties in South Dakota. It was in force for 41 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, 2:34 AM CDT (07:34 UTC)
Expired: Jul 9, 2021, 3:15 AM CDT
In force: 41 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Hanson County, SD, Lake County, SD, McCook County, SD, Miner County, SD

The radar

The Sioux Falls radar (KFSD), 64 km from the middle of the area, began a volume at 07:33 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, 7.6 hours before the alert went out and 151 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.

138 
WUUS53 KFSD 090734
SVRFSD
SDC061-079-087-097-090815-
/O.NEW.KFSD.SV.W.0059.210709T0734Z-210709T0815Z/

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

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Southwestern Lake County in east central South Dakota...
  Southeastern Miner County in east central South Dakota...
  McCook County in southeastern South Dakota...
  Eastern Hanson County in southeastern South Dakota...

* Until 315 AM CDT.

* At 233 AM CDT, a severe thunderstorm was located over Spencer In
  McCook County, or 21 miles east of Mitchell, moving east at 40 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...
  Salem around 250 AM CDT.
  Canistota around 300 AM CDT.
  Montrose around 305 AM CDT.
  Lake Vermillion State Recreation Area around 310 AM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4352 9782 4397 9767 4395 9712 4351 9715
TIME...MOT...LOC 0733Z 283DEG 34KT 4374 9761 

HAIL...1.00IN
WIND...60MPH
 
$$

SSC

1 follow-up statement

662 
WWUS53 KFSD 090755
SVSFSD

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

SDC061-079-087-097-090815-
/O.CON.KFSD.SV.W.0059.000000T0000Z-210709T0815Z/
Lake SD-Miner SD-McCook SD-Hanson SD-
255 AM CDT Fri Jul 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 AM CDT
FOR SOUTHWESTERN LAKE...SOUTHEASTERN MINER...MCCOOK AND EAST CENTRAL
HANSON COUNTIES...

At 255 AM CDT, Doppler radar indicated a severe thunderstorm capable
of producing quarter size hail and damaging winds in excess of 60
mph. This storm was located near Salem, or 10 miles northwest of Lake
Vermillion State Recreation Area, moving east at 40 mph.

This severe storm will be near...
  Montrose around 305 AM CDT.
  Lake Vermillion State Recreation Area around 310 AM CDT.

LAT...LON 4352 9763 4396 9758 4395 9712 4351 9715
TIME...MOT...LOC 0755Z 283DEG 34KT 4369 9733 

$$

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, 1:22 AM CDT	Severe Thunderstorm Warning	FSD	Aurora, Davison, Jerauld, Sanborn	38 min
Jul 9, 2:15 AM CDT	Severe Thunderstorm Warning	FSD	Lincoln, Union	45 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.