Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 101, NWS Twin Cities, MN

August 28, 2021Swift County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 28, 2021, 10:31 AM CDT for Swift County, Minnesota. It was in force for 44 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: Aug 28, 2021, 10:31 AM CDT (15:31 UTC)
Expired: Aug 28, 2021, 11:15 AM CDT
In force: 44 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Damage threat: Destructive
Hail: 2.75 in
Wind: 60.0 mph

County Swift County, MN

The radar

The Minneapolis radar (KMPX), 157 km from the middle of the area, began a volume at 15:30 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
Aug 28, 7:08 AM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 3.5 hours before the alert went out and 154 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: 1550 J/kg
Mixed-layer CIN: -130 J/kg
Mixed-layer LCL: 676 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 139 m²/s²
0-3 km storm-relative helicity: 193 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

350 
WUUS53 KMPX 281531
SVRMPX
MNC151-281615-
/O.NEW.KMPX.SV.W.0101.210828T1531Z-210828T1615Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
1031 AM CDT Sat Aug 28 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Northeastern Swift County in west central Minnesota...

* Until 1115 AM CDT.

* At 1030 AM CDT, a severe thunderstorm was located over Benson, or
  22 miles southeast of Morris, moving east at 35 mph.

  THIS IS A DESTRUCTIVE STORM FOR BENSON AND NORTHEAST SWIFT COUNTY.

  HAZARD...Baseball size hail and 60 mph wind gusts.

  SOURCE...Trained weather spotters.

  IMPACT...People and animals outdoors will be severely injured. 
           Expect shattered windows, extensive damage to roofs, 
           siding, and vehicles.

* This severe thunderstorm will be near...
  Benson around 1035 AM CDT.
  Lake Hassel around 1040 AM CDT.
  Murdock around 1055 AM CDT.

Other locations impacted by this severe thunderstorm include De 
Graff, Swift Falls and Clontarf.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4541 9525 4522 9525 4522 9571 4541 9574
TIME...MOT...LOC 1530Z 269DEG 31KT 4531 9566 

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...2.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

1 follow-up statement

360 
WWUS53 KMPX 281605
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1105 AM CDT Sat Aug 28 2021

MNC151-281615-
/O.EXP.KMPX.SV.W.0101.000000T0000Z-210828T1615Z/
Swift MN-
1105 AM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN SWIFT COUNTY WILL
EXPIRE AT 1115 AM CDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.

A Severe Thunderstorm Watch remains in effect until noon CDT for
central and west central Minnesota.

LAT...LON 4541 9525 4522 9525 4522 9571 4541 9574
TIME...MOT...LOC 1605Z 269DEG 31KT 4536 9528 

$$

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 27, 8:21 PM CDT	Flash Flood Warning	MPX	Freeborn	4 hr
Aug 27, 11:48 PM CDT	Special Weather Statement	MPX	Freeborn	87 min
Aug 28, 8:14 AM CDT	Special Weather Statement	MPX	Stevens	61 min
Aug 28, 9:27 AM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Lac qui Parle	33 min
Aug 28, 9:49 AM CDT	Severe Thunderstorm Warning	MPX	Douglas, Pope, Stevens	56 min
Aug 28, 9:54 AM CDT	Severe Thunderstorm Warning	MPX	Swift	51 min
Aug 28, 10:41 AM CDT	Severe Thunderstorm Warning	MPX	Douglas, Pope, Stearns, Todd	49 min
Aug 28, 10:53 AM CDT	Severe Thunderstorm Warning	MPX	Kandiyohi	52 min
Aug 28, 11:20 AM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Stearns	40 min
Aug 28, 11:24 AM CDT	Tornado Warning	MPX	Stearns	36 min
Aug 28, 11:32 AM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Morrison, Todd	43 min
Aug 28, 11:45 AM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Benton, Mille Lacs, Morrison, Sherburne	45 min
Aug 28, 12:04 PM CDT	Tornado Warning	MPX	Benton, Mille Lacs	41 min
Aug 28, 12:27 PM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Isanti, Kanabec, Mille Lacs	48 min
Aug 28, 12:43 PM CDT	Special Weather Statement	MPX	Anoka	47 min
Aug 28, 1:07 PM CDT	Special Weather Statement	MPX	Chisago	23 min
Aug 28, 1:29 PM CDT	Severe Thunderstorm Warning	MPX	Chisago, Isanti	46 min
Aug 28, 6:06 PM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Brown, Redwood, Watonwan	54 min
Aug 28, 6:19 PM CDT	Tornado Warning	MPX	Brown, Redwood	26 min
Aug 28, 6:26 PM CDT	Severe Thunderstorm Warning Considerable damage threat	MPX	Blue Earth, Faribault, Martin, Watonwan	64 min
Aug 28, 6:43 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Brown, Nicollet, Redwood, Renville, Sibley and 1 more	62 min
Aug 28, 6:51 PM CDT	Tornado Warning	MPX	Brown, Nicollet	24 min

Nearby

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.