Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 82, NWS La Crosse, WI

August 11, 2021La Crosse County, Monroe County, Vernon County, Wisconsin; Houston County, Minnesota

NWS La Crosse, WI issued this severe thunderstorm warning at Aug 11, 2021, 2:18 PM CDT for La Crosse County, Monroe County, Vernon County, Wisconsin; Houston County, Minnesota. It was in force for 42 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 11, 2021, 2:18 PM CDT (19:18 UTC)
Expired
Aug 11, 2021, 3:00 PM CDT
In force
42 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Houston County, MN, La Crosse County, WI, Monroe County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 18 km from the middle of the area, began a volume at 19:22 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.

IssuedProductOfficeLasted
Aug 11, 12:17 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 7.3 hours before the alert went out and 233 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, Davenport, at 12:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2852 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, Davenport, at 12:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.19395878Sfc1 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
2852 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
1040 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
193 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.7

Open this sounding in Storm Lab

The text

As transmitted.

319 
WUUS53 KARX 111918
SVRARX
MNC055-WIC063-081-123-112000-
/O.NEW.KARX.SV.W.0082.210811T1918Z-210811T2000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service La Crosse WI
218 PM CDT Wed Aug 11 2021

The National Weather Service in La Crosse has issued a

* Severe Thunderstorm Warning for...
  East central Houston County in southeastern Minnesota...
  Southeastern La Crosse County in west central Wisconsin...
  Northwestern Vernon County in southwestern Wisconsin...
  Southwestern Monroe County in west central Wisconsin...

* Until 300 PM CDT.

* At 217 PM CDT, a severe thunderstorm was located over Stoddard, or
  11 miles east of Caledonia, moving east at 35 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...
  Coon Valley around 240 PM CDT.
  Viroqua around 250 PM CDT.
  Westby around 255 PM CDT.
  Cashton around 300 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CDT for southeastern
Minnesota...and southwestern and west central Wisconsin.

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

&&

LAT...LON 4361 9137 4375 9138 4381 9075 4355 9075
TIME...MOT...LOC 1917Z 270DEG 30KT 4366 9127 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JSB
3 follow-up statements
615 
WWUS53 KARX 111933
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
233 PM CDT Wed Aug 11 2021

MNC055-111943-
/O.CAN.KARX.SV.W.0082.000000T0000Z-210811T2000Z/
Houston MN-
233 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL HOUSTON COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 800 PM CDT for southeastern
Minnesota...and southwestern and west central Wisconsin.

LAT...LON 4360 9124 4361 9126 4371 9127 4372 9126
      4374 9125 4381 9075 4355 9075
TIME...MOT...LOC 1933Z 270DEG 30KT 4366 9108 

$$

WIC063-081-123-112000-
/O.CON.KARX.SV.W.0082.000000T0000Z-210811T2000Z/
La Crosse WI-Vernon WI-Monroe WI-
233 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR SOUTHEASTERN LA CROSSE...NORTHWESTERN VERNON AND SOUTHWESTERN
MONROE COUNTIES...

At 233 PM CDT, a severe thunderstorm was located near Coon Valley, or
12 miles northwest of Viroqua, moving east at 35 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.

Locations impacted include...
  Viroqua, Westby and Cashton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CDT for southeastern
Minnesota...and southwestern and west central Wisconsin.

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

&&

LAT...LON 4360 9124 4361 9126 4371 9127 4372 9126
      4374 9125 4381 9075 4355 9075
TIME...MOT...LOC 1933Z 270DEG 30KT 4366 9108 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JSB
686 
WWUS53 KARX 111947
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
247 PM CDT Wed Aug 11 2021

WIC063-081-111957-
/O.CAN.KARX.SV.W.0082.000000T0000Z-210811T2000Z/
La Crosse WI-Monroe WI-
247 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LA CROSSE AND
SOUTHWESTERN MONROE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 800 PM CDT for southwestern
and west central Wisconsin.

LAT...LON 4360 9120 4372 9106 4373 9085 4372 9075
      4355 9075
TIME...MOT...LOC 1947Z 273DEG 35KT 4361 9106 

$$

WIC123-112000-
/O.CON.KARX.SV.W.0082.000000T0000Z-210811T2000Z/
Vernon WI-
247 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 300 PM CDT
FOR NORTHWESTERN VERNON COUNTY...

At 247 PM CDT, a severe thunderstorm was located 7 miles south of
Coon Valley, or 9 miles west of Viroqua, 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.

Locations impacted include...
Viroqua, Westby, Coon Valley, Springville, Chaseburg, Jersey Valley
County Park, Esofea, Spring Ridge, County Roads O And Y, Runge
Hollow, County Roads B And Y, Avalanche, County Roads K And O, Newry
and Bloomingdale.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CDT for southwestern
and west central Wisconsin.

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

&&

LAT...LON 4360 9120 4372 9106 4373 9085 4372 9075
      4355 9075
TIME...MOT...LOC 1947Z 273DEG 35KT 4361 9106 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

JSB
919 
WWUS53 KARX 112000
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
300 PM CDT Wed Aug 11 2021

WIC123-112009-
/O.EXP.KARX.SV.W.0082.000000T0000Z-210811T2000Z/
Vernon WI-
300 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN VERNON COUNTY
WILL EXPIRE AT 300 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small hail
is still possible with this thunderstorm.

A Tornado Watch remains in effect until 800 PM CDT for southwestern
and west central Wisconsin.

LAT...LON 4360 9120 4372 9106 4373 9085 4372 9075
      4355 9075
TIME...MOT...LOC 1959Z 270DEG 30KT 4361 9093 

$$

JSB

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 10, 9:19 PM CDTRiver Flood WarningARXLa Crosse, Trempealeau30 hr
Aug 11, 11:32 AM CDTSpecial Weather StatementARXTaylor28 min
Aug 11, 11:57 AM CDTSpecial Weather StatementARXClark, Taylor33 min
Aug 11, 12:18 PM CDTSevere Thunderstorm WarningARXTaylor42 min
Aug 11, 12:31 PM CDTSpecial Weather StatementARXClark, Jackson, La Crosse, Monroe59 min
Aug 11, 1:01 PM CDTTornado WarningARXClark17 min
Aug 11, 1:07 PM CDTSevere Thunderstorm WarningARXLa Crosse, Monroe38 min
Aug 11, 1:41 PM CDTSevere Thunderstorm WarningARXJuneau, Monroe64 min
Aug 11, 1:48 PM CDTTornado WarningARXJuneau, Monroe42 min
Aug 11, 2:06 PM CDTSevere Thunderstorm WarningARXLa Crosse, Monroe39 min
Aug 11, 2:20 PM CDTTornado Warning Tornado observedConsiderable damage threatARXAdams, Juneau, Monroe55 min
Aug 11, 2:32 PM CDTSevere Thunderstorm WarningARXMonroe28 min
Aug 11, 3:06 PM CDTSevere Thunderstorm WarningARXRichland, Vernon54 min
Aug 11, 4:19 PM CDTSpecial Weather StatementARXGrant26 min
Aug 11, 4:23 PM CDTSevere Thunderstorm WarningARXGrant22 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021Severe 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.