Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 111, NWS Twin Cities, MN

August 28, 20217 counties in Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 28, 2021, 6:43 PM CDT for 7 counties in Minnesota. It was in force for 62 min. 3 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, 6:43 PM CDT (23:43 UTC)
Expired: Aug 28, 2021, 7:45 PM CDT
In force: 62 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Blue Earth County, MN, Brown County, MN, Nicollet County, MN, Redwood County, MN, Renville County, MN, Sibley County, MN, Watonwan County, MN

The radar

The Minneapolis radar (KMPX), 80 km from the middle of the area, began a volume at 23:43 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, 6:46 PM CDT	TSTM WND DMG	Sleepy Eye, MN	WIND DAMAGE/TREES DOWN SOUTH PART OF SLEEPY EYE.
Aug 28, 7:07 PM CDT	TSTM WND GST 60	Oshawa, MN
Aug 28, 7:45 PM CDT	TSTM WND DMG	Courtland, MN	PHOTO ON TWITTER OF A MATURE TREE DOWN. BROKE OFF SEVERAL FEET ABOVE ITS BASE. TIME ESTIMATED FROM RADAR.

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, 5:59 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.7 hours before the alert went out and 78 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.

313 
WUUS53 KMPX 282343
SVRMPX
MNC013-015-103-127-129-143-165-290045-
/O.NEW.KMPX.SV.W.0111.210828T2343Z-210829T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
643 PM CDT Sat Aug 28 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Southeastern Redwood County in southwestern Minnesota...
  Sibley County in central Minnesota...
  Brown County in south central Minnesota...
  Northern Blue Earth County in south central Minnesota...
  Northeastern Watonwan County in south central Minnesota...
  Southeastern Renville County in central Minnesota...
  Nicollet County in south central Minnesota...

* Until 745 PM CDT.

* At 642 PM CDT, severe thunderstorms were located along a line
  extending from near Hanska to Sleepy Eye to 8 miles northwest of
  Springfield, moving northeast at 50 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Hanska around 650 PM CDT.
  New Ulm around 655 PM CDT.
  Courtland and Franklin around 700 PM CDT.

Other locations in the path of these severe thunderstorms include
Lafayette, Fairfax, Nicollet, North Mankato, Gibbon and St. Peter.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 4423 9481 4431 9530 4467 9466 4463 9449
      4464 9440 4455 9390 4451 9388 4439 9396
      4434 9393 4428 9402 4424 9403 4424 9377
      4412 9377 4410 9435 4406 9456
TIME...MOT...LOC 2342Z 244DEG 42KT 4412 9457 4427 9471 4433 9510 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

NDC

2 follow-up statements

220 
WWUS53 KMPX 290017
SVSMPX

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

MNC127-129-290026-
/O.CAN.KMPX.SV.W.0111.000000T0000Z-210829T0045Z/
Redwood MN-Renville MN-
717 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN REDWOOD AND
SOUTHEASTERN RENVILLE COUNTIES 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 1100 PM CDT for
south central, central and east central Minnesota.

LAT...LON 4428 9476 4449 9483 4446 9480 4446 9463
      4466 9462 4455 9391 4451 9388 4439 9396
      4434 9393 4428 9402 4424 9403 4424 9377
      4412 9377 4410 9435 4406 9456
TIME...MOT...LOC 0016Z 244DEG 42KT 4429 9408 4444 9422 4450 9461 

$$

MNC013-015-103-143-165-290045-
/O.CON.KMPX.SV.W.0111.000000T0000Z-210829T0045Z/
Sibley MN-Brown MN-Blue Earth MN-Watonwan MN-Nicollet MN-
717 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR SIBLEY...EASTERN BROWN...NORTHERN BLUE EARTH...NORTHEASTERN
WATONWAN AND NICOLLET COUNTIES...

At 716 PM CDT, severe thunderstorms were located along a line
extending from 5 miles west of Kasota to 7 miles south of Gaylord to
near Gibbon, moving northeast at 50 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
  St. Peter, Winthrop, Le Sueur, Henderson and Gaylord.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

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

&&

LAT...LON 4428 9476 4449 9483 4446 9480 4446 9463
      4466 9462 4455 9391 4451 9388 4439 9396
      4434 9393 4428 9402 4424 9403 4424 9377
      4412 9377 4410 9435 4406 9456
TIME...MOT...LOC 0016Z 244DEG 42KT 4429 9408 4444 9422 4450 9461 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

NDC

319 
WWUS53 KMPX 290035
SVSMPX

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

MNC013-015-103-143-165-290045-
/O.EXP.KMPX.SV.W.0111.000000T0000Z-210829T0045Z/
Sibley MN-Brown MN-Blue Earth MN-Watonwan MN-Nicollet MN-
735 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR SIBLEY...EASTERN BROWN...
NORTHERN BLUE EARTH...NORTHEASTERN WATONWAN AND NICOLLET COUNTIES
WILL EXPIRE AT 745 PM CDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 1100 PM CDT for
south central, central and east central Minnesota.

LAT...LON 4428 9476 4449 9483 4446 9480 4446 9463
      4466 9462 4455 9391 4451 9388 4439 9396
      4434 9393 4428 9402 4424 9403 4424 9377
      4412 9377 4410 9435 4406 9456
TIME...MOT...LOC 0035Z 244DEG 42KT 4438 9381 4453 9395 4459 9434 

$$

NDC

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, 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, 6:51 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.