Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 106, NWS Twin Cities, MN

August 28, 20214 counties in Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 28, 2021, 11:45 AM CDT for 4 counties in Minnesota. It was in force for 45 min. 8 reports 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, 11:45 AM CDT (16:45 UTC)
Expired: Aug 28, 2021, 12:30 PM CDT
In force: 45 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Tornado: Possible
Damage threat: Considerable
Hail: 2.0 in
Wind: 70.0 mph

Counties Benton County, MN, Mille Lacs County, MN, Morrison County, MN, Sherburne County, MN

The radar

The Minneapolis radar (KMPX), 108 km from the middle of the area, began a volume at 16:48 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, 11:50 AM CDT	HAIL 1.5	Sartell, MN	PING PONG BALL SIZED HAIL WITH ESTIMATED 58 MPH WINDS.
Aug 28, 11:55 AM CDT	HAIL 1.25	1 N Sauk Rapids, MN	HAIL DAMAGED HOME SIDING.
Aug 28, 11:55 AM CDT	HAIL 1.5	Sauk Rapids, MN	TIME ESTIMATED BASED ON RADAR.
Aug 28, 11:58 AM CDT	HAIL 2	1 W Royalton, MN
Aug 28, 12:00 PM CDT	HAIL 1.75	5 Sw Gilman, MN	PICTURE FROM SOCIAL MEDIA WITH A HALF DOLLAR AND GOLF BALL SIZED HAIL STONE WITH TIME ESTIMATED BASED ON RADAR.
Aug 28, 12:00 PM CDT	HAIL 2.5	5 Ne Sauk Rapids, MN	HAIL WAS MEASURED. IT WAS ALSO WEIGHED THE NEXT DAY AT 2.64 OUNCES. MULTIPLE VEHICLES HAD WINDOWS BROKEN AND WERE DENTED. SIDING ON HOUSES WAS ALSO DENTED. WINDOWS WERE BROKEN IN HOUSES AND OUTBUILDINGS.
Aug 28, 12:25 PM CDT	TSTM WND DMG	2 N Milaca, MN	FEW TREES DOWN, INCLUDING ONE ON A ROAD.
Aug 28, 12:30 PM CDT	HAIL 1	2 Nw Foreston, MN	PICTURE MULTIPLE HAIL STONES UP TO THE SIZE OF QUARTERS.

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, 7:08 AM CDT	Severe Thunderstorm Watch	SPC	5 hr
Aug 28, 10:34 AM CDT	Tornado Watch	SPC	4 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 4.8 hours before the alert went out and 107 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.

515 
WUUS53 KMPX 281645
SVRMPX
MNC009-095-097-141-281730-
/O.NEW.KMPX.SV.W.0106.210828T1645Z-210828T1730Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
1145 AM CDT Sat Aug 28 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Southern Mille Lacs County in east central Minnesota...
  Benton County in central Minnesota...
  Northern Sherburne County in central Minnesota...
  Southeastern Morrison County in central Minnesota...

* Until 1230 PM CDT.

* At 1145 AM CDT, severe thunderstorms were located along a line
  extending from near Bowlus to 5 miles north of Sauk Rapids to near
  Rockville, moving east at 55 mph.

  HAZARD...Two inch hail and 70 mph wind gusts.

  SOURCE...Trained weather spotters.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings.

* Severe thunderstorms will be near...
  St. Cloud and Foley around 1200 PM CDT.
  Foreston around 1210 PM CDT.
  Milaca around 1215 PM CDT.
  Bock around 1220 PM CDT.
  Princeton around 1225 PM CDT.

Other locations impacted by these severe thunderstorms include Duelm,
Mayhew, Morrill, Glendorado, Parent, St Cloud Airport, Pease, Oak
Park, Princeton Airport and Santiago.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 400 PM CDT for central and
east central Minnesota.

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

&&

LAT...LON 4602 9358 4597 9352 4553 9352 4549 9414
      4556 9415 4562 9421 4568 9419 4571 9423
      4572 9422 4573 9426 4576 9427 4578 9433
      4583 9436 4592 9436
TIME...MOT...LOC 1645Z 255DEG 49KT 4579 9435 4567 9421 4548 9430 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...2.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

1 follow-up statement

970 
WWUS53 KMPX 281718
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1218 PM CDT Sat Aug 28 2021

MNC009-095-097-141-281730-
/O.CON.KMPX.SV.W.0106.000000T0000Z-210828T1730Z/
Mille Lacs MN-Benton MN-Sherburne MN-Morrison MN-
1218 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 PM CDT
FOR SOUTHERN MILLE LACS...BENTON...NORTHERN SHERBURNE AND
SOUTHEASTERN MORRISON COUNTIES...

At 1218 PM CDT, severe thunderstorms were located along a line
extending from 12 miles east of Pierz to near Milaca to 6 miles
southeast of Foley, moving east at 50 mph.

HAZARD...Two inch hail and 70 mph wind gusts.

SOURCE...Trained weather spotters.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings.

These severe storms will be near...
  Bock around 1225 PM CDT.

Other locations impacted by these severe thunderstorms include 
Duelm, Mayhew, Morrill, Glendorado, Parent, Pease, Oak Park, 
and Santiago.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 400 PM CDT for central and
east central Minnesota.

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

&&

LAT...LON 4602 9358 4597 9352 4553 9352 4549 9414
      4573 9406 4592 9436
TIME...MOT...LOC 1718Z 250DEG 45KT 4593 9385 4581 9371 4562 9380 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...2.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

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, 10:31 AM CDT	Severe Thunderstorm Warning Destructive damage threat	MPX	Swift	44 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, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.