Alert archive / Minnesota / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 110, NWS Twin Cities, MN

August 28, 20214 counties in Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 28, 2021, 6:26 PM CDT for 4 counties in Minnesota. It was in force for 64 min. 2 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, 6:26 PM CDT (23:26 UTC)
Expired
Aug 28, 2021, 7:30 PM CDT
In force
64 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Damage threat
Considerable
Hail
0.75 in
Wind
70.0 mph

Counties Blue Earth County, MN, Faribault County, MN, Martin County, MN, Watonwan County, MN

The radar

The Minneapolis radar (KMPX), 123 km from the middle of the area, began a volume at 23:30 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.

What was reported inside it

TimeReportWhereRemark
Aug 28, 6:45 PM CDTFUNNEL CLOUD1 N Madelia, MNFUNNEL CLOUD 1N MADELIA.
Aug 28, 6:50 PM CDTTSTM WND DMGSt. James, MNTREES DOWN IN ST. JAMES.

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.

IssuedProductOfficeLasted
Aug 28, 5:59 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 11.4 hours before the alert went out and 122 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-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2021-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1550 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2021-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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.

719 
WUUS53 KMPX 282326
SVRMPX
MNC013-043-091-165-290030-
/O.NEW.KMPX.SV.W.0110.210828T2326Z-210829T0030Z/

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

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Northwestern Faribault County in south central Minnesota...
  Northern Martin County in south central Minnesota...
  Blue Earth County in south central Minnesota...
  Watonwan County in south central Minnesota...

* Until 730 PM CDT.

* At 624 PM CDT, severe thunderstorms were located along a line
  extending from near Comfrey to near Kilen Woods State Park, moving 
  east at 50 mph. At 615 PM CDT a 66 MPH wind gust was observed near 
  Windom, MN.

  HAZARD...70 mph wind gusts.

  SOURCE...Automated Observation.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Severe thunderstorms will be near...
  Butterfield around 630 PM CDT.
  St. James around 640 PM CDT.

Other locations in the path of these severe thunderstorms include
Trimont, Madelia, Lake Crystal, Truman, Good Thunder, Winnebago,
Amboy, St. Clair, Easton and Delavan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4366 9485 4399 9486 4411 9440 4411 9437
      4412 9436 4412 9379 4364 9389
TIME...MOT...LOC 2324Z 267DEG 44KT 4406 9491 4376 9510 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...70 MPH

$$

NDC
4 follow-up statements
854 
WWUS53 KMPX 282338
SVSMPX

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

MNC043-282348-
/O.CAN.KMPX.SV.W.0110.000000T0000Z-210829T0030Z/
Faribault MN-
638 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN FARIBAULT COUNTY
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 Minnesota.

LAT...LON 4396 9486 4401 9480 4411 9442 4411 9437
      4412 9436 4412 9379 4386 9384 4385 9425
      4383 9426 4379 9485
TIME...MOT...LOC 2338Z 250DEG 46KT 4412 9463 4389 9493 

$$

MNC013-091-165-290030-
/O.CON.KMPX.SV.W.0110.000000T0000Z-210829T0030Z/
Martin MN-Blue Earth MN-Watonwan MN-
638 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR NORTHERN MARTIN...BLUE EARTH AND WATONWAN COUNTIES...

At 638 PM CDT, severe thunderstorms were located along a line
extending from 7 miles west of Hanska to near Mountain Lake, moving
east at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
  St. James, Lewisville, Madelia, Vernon Center, Lake Crystal, Good 
  Thunder and St. Clair.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4396 9486 4401 9480 4411 9442 4411 9437
      4412 9436 4412 9379 4386 9384 4385 9425
      4383 9426 4379 9485
TIME...MOT...LOC 2338Z 250DEG 46KT 4412 9463 4389 9493 

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

$$

NDC
145 
WWUS53 KMPX 282353
SVSMPX

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

MNC091-290003-
/O.CAN.KMPX.SV.W.0110.000000T0000Z-210829T0030Z/
Martin MN-
653 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN MARTIN COUNTY 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 Minnesota.

LAT...LON 4385 9472 4385 9485 4396 9486 4401 9480
      4410 9441 4412 9436 4412 9379 4386 9384
      4385 9426 4384 9471
TIME...MOT...LOC 2353Z 265DEG 41KT 4412 9440 4391 9476 

$$

MNC013-165-290030-
/O.CON.KMPX.SV.W.0110.000000T0000Z-210829T0030Z/
Blue Earth MN-Watonwan MN-
653 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR BLUE EARTH AND WATONWAN COUNTIES...

At 653 PM CDT, severe thunderstorms were located along a line
extending from 5 miles north of Madelia to near Butterfield, moving
east at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
St. James, Lake Crystal, Madelia, Mapleton, St. Clair, Butterfield,
Good Thunder, Amboy, Vernon Center, Lewisville, Garden City and South
Branch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4385 9472 4385 9485 4396 9486 4401 9480
      4410 9441 4412 9436 4412 9379 4386 9384
      4385 9426 4384 9471
TIME...MOT...LOC 2353Z 265DEG 41KT 4412 9440 4391 9476 

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

$$

NDC
726 
WWUS53 KMPX 290009
SVSMPX

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

MNC013-165-290030-
/O.CON.KMPX.SV.W.0110.000000T0000Z-210829T0030Z/
Blue Earth MN-Watonwan MN-
709 PM CDT Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM CDT
FOR BLUE EARTH AND EASTERN WATONWAN COUNTIES...

At 709 PM CDT, severe thunderstorms were located along a line
extending from near Lake Crystal to near Lewisville, moving east at
50 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Lake Crystal, Madelia, Mapleton, St. Clair, Good Thunder, Amboy,
Vernon Center, Lewisville, Garden City, Grogan and St James Airport.

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 4410 9441 4411 9430 4412 9379 4386 9384
      4389 9458 4407 9456
TIME...MOT...LOC 0009Z 267DEG 44KT 4413 9416 4392 9452 

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

$$

NDC
734 
WWUS53 KMPX 290030
SVSMPX

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

MNC013-165-290040-
/O.EXP.KMPX.SV.W.0110.000000T0000Z-210829T0030Z/
Blue Earth MN-Watonwan MN-
730 PM CDT Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR BLUE EARTH AND EASTERN
WATONWAN COUNTIES HAS EXPIRED...
            
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 has been allowed to expire.

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

LAT...LON 4410 9441 4411 9430 4412 9379 4386 9384
      4389 9458 4407 9456
TIME...MOT...LOC 0030Z 267DEG 44KT 4414 9384 4393 9420 

$$

NDC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 8:21 PM CDTFlash Flood WarningMPXFreeborn4 hr
Aug 27, 11:48 PM CDTSpecial Weather StatementMPXFreeborn87 min
Aug 28, 8:14 AM CDTSpecial Weather StatementMPXStevens61 min
Aug 28, 9:27 AM CDTSevere Thunderstorm Warning Considerable damage threatMPXLac qui Parle33 min
Aug 28, 9:49 AM CDTSevere Thunderstorm WarningMPXDouglas, Pope, Stevens56 min
Aug 28, 9:54 AM CDTSevere Thunderstorm WarningMPXSwift51 min
Aug 28, 10:31 AM CDTSevere Thunderstorm Warning Destructive damage threatMPXSwift44 min
Aug 28, 10:41 AM CDTSevere Thunderstorm WarningMPXDouglas, Pope, Stearns, Todd49 min
Aug 28, 10:53 AM CDTSevere Thunderstorm WarningMPXKandiyohi52 min
Aug 28, 11:20 AM CDTSevere Thunderstorm Warning Considerable damage threatMPXStearns40 min
Aug 28, 11:24 AM CDTTornado WarningMPXStearns36 min
Aug 28, 11:32 AM CDTSevere Thunderstorm Warning Considerable damage threatMPXMorrison, Todd43 min
Aug 28, 11:45 AM CDTSevere Thunderstorm Warning Considerable damage threatMPXBenton, Mille Lacs, Morrison, Sherburne45 min
Aug 28, 12:04 PM CDTTornado WarningMPXBenton, Mille Lacs41 min
Aug 28, 12:27 PM CDTSevere Thunderstorm Warning Considerable damage threatMPXIsanti, Kanabec, Mille Lacs48 min
Aug 28, 12:43 PM CDTSpecial Weather StatementMPXAnoka47 min
Aug 28, 1:07 PM CDTSpecial Weather StatementMPXChisago23 min
Aug 28, 1:29 PM CDTSevere Thunderstorm WarningMPXChisago, Isanti46 min
Aug 28, 6:06 PM CDTSevere Thunderstorm Warning Considerable damage threatMPXBrown, Redwood, Watonwan54 min
Aug 28, 6:19 PM CDTTornado WarningMPXBrown, Redwood26 min
Aug 28, 6:43 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Brown, Nicollet, Redwood, Renville, Sibley and 1 more62 min
Aug 28, 6:51 PM CDTTornado WarningMPXBrown, Nicollet24 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2021Every 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.