Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 79, NWS La Crosse, WI

August 11, 2021La Crosse County, Monroe County, Wisconsin

NWS La Crosse, WI issued this severe thunderstorm warning at Aug 11, 2021, 1:07 PM CDT for La Crosse County, Monroe County, Wisconsin. It was in force for 38 min. 1 report 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 11, 2021, 1:07 PM CDT (18:07 UTC)
Expired: Aug 11, 2021, 1:45 PM CDT
In force: 38 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Tornado: Possible
Hail: 1.25 in
Wind: 60.0 mph

Counties La Crosse County, WI, Monroe County, WI

The radar

The La Crosse radar (KARX), 34 km from the middle of the area, began a volume at 18:10 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 11, 1:22 PM CDT	HAIL 1	1 S Sparta, WI

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 11, 12:17 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 6.1 hours before the alert went out and 224 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: 1499 J/kg
Mixed-layer CIN: -136 J/kg
Mixed-layer LCL: 678 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 156 m²/s²
0-3 km storm-relative helicity: 206 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

904 
WUUS53 KARX 111807
SVRARX
WIC063-081-111845-
/O.NEW.KARX.SV.W.0079.210811T1807Z-210811T1845Z/

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

The National Weather Service in La Crosse has issued a

* Severe Thunderstorm Warning for...
  Southeastern La Crosse County in west central Wisconsin...
  Central Monroe County in west central Wisconsin...

* Until 145 PM CDT.

* At 106 PM CDT, a severe thunderstorm was located over Bangor, or 8
  miles southwest of Sparta, moving east at 30 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Sparta, Tomah, West Salem, Bangor, Fort Mc Coy, Norwalk, Rockland, 
  Wilton, Ridgeville, Kendall, Oakdale, Wyeville, Melvina,  Lake 
  Neshonoc, St Marys and Jackson Pass.

This includes the following highways...
 Interstate 94 between mile markers 142 and 147.
 Interstate 90/94 between mile markers 46 and 49.
 Interstate 90 in Wisconsin between mile markers 13 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

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

&&

LAT...LON 4379 9105 4397 9107 4406 9038 4379 9034
TIME...MOT...LOC 1806Z 264DEG 27KT 4389 9095 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DTJ

2 follow-up statements

458 
WWUS53 KARX 111820
SVSARX

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

WIC063-081-111845-
/O.CON.KARX.SV.W.0079.000000T0000Z-210811T1845Z/
La Crosse WI-Monroe WI-
120 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR EAST CENTRAL LA CROSSE AND CENTRAL MONROE COUNTIES...

At 119 PM CDT, a severe thunderstorm was located over Sparta, moving
east at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Sparta, Tomah, Bangor, Fort Mc Coy, Leon, Norwalk, Rockland, Wilton, 
Kendall, Oakdale, Wyeville, Melvina, Jackson Pass,  Tunnel City, and 
County A.

This includes the following highways...
 Interstate 94 between mile markers 142 and 147.
 Interstate 90/94 between mile markers 46 and 49.
 Interstate 90 in Wisconsin between mile markers 16 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4380 9100 4397 9101 4406 9038 4379 9034
TIME...MOT...LOC 1819Z 264DEG 27KT 4390 9081 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DTJ

595 
WWUS53 KARX 111831
SVSARX

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

WIC063-111839-
/O.CAN.KARX.SV.W.0079.000000T0000Z-210811T1845Z/
La Crosse WI-
131 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL LA CROSSE 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 west central
Wisconsin.

LAT...LON 4381 9091 4397 9091 4406 9038 4379 9034
TIME...MOT...LOC 1829Z 264DEG 27KT 4391 9070 

$$

WIC081-111845-
/O.CON.KARX.SV.W.0079.000000T0000Z-210811T1845Z/
Monroe WI-
131 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 145 PM CDT
FOR CENTRAL MONROE COUNTY...

At 129 PM CDT, a severe thunderstorm was located near Sparta, moving
east at 40 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Law enforcement reported 1 inch size hail 1 mile south of 
         Sparta.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Sparta, Tomah, Leon, Norwalk, Rockland, Wilton, Ridgeville, Kendall, 
Oakdale, Wyeville, Melvina, Jackson Pass, Tunnel City, and Tunnel 
Trail Campground.

This includes the following highways...
 Interstate 94 between mile markers 143 and 147.
 Interstate 90/94 between mile markers 46 and 49.
 Interstate 90 in Wisconsin between mile markers 21 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4381 9091 4397 9091 4406 9038 4379 9034
TIME...MOT...LOC 1829Z 264DEG 27KT 4391 9070 

TORNADO...POSSIBLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DTJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 9:19 PM CDT	River Flood Warning	ARX	La Crosse, Trempealeau	30 hr
Aug 11, 11:32 AM CDT	Special Weather Statement	ARX	Taylor	28 min
Aug 11, 11:57 AM CDT	Special Weather Statement	ARX	Clark, Taylor	33 min
Aug 11, 12:18 PM CDT	Severe Thunderstorm Warning	ARX	Taylor	42 min
Aug 11, 12:31 PM CDT	Special Weather Statement	ARX	Clark, Jackson, La Crosse, Monroe	59 min
Aug 11, 1:01 PM CDT	Tornado Warning	ARX	Clark	17 min
Aug 11, 1:41 PM CDT	Severe Thunderstorm Warning	ARX	Juneau, Monroe	64 min
Aug 11, 1:48 PM CDT	Tornado Warning	ARX	Juneau, Monroe	42 min
Aug 11, 2:06 PM CDT	Severe Thunderstorm Warning	ARX	La Crosse, Monroe	39 min
Aug 11, 2:18 PM CDT	Severe Thunderstorm Warning	ARX	La Crosse, Monroe, Vernon	42 min
Aug 11, 2:20 PM CDT	Tornado Warning Tornado observedConsiderable damage threat	ARX	Adams, Juneau, Monroe	55 min
Aug 11, 2:32 PM CDT	Severe Thunderstorm Warning	ARX	Monroe	28 min
Aug 11, 3:06 PM CDT	Severe Thunderstorm Warning	ARX	Richland, Vernon	54 min
Aug 11, 4:19 PM CDT	Special Weather Statement	ARX	Grant	26 min
Aug 11, 4:23 PM CDT	Severe Thunderstorm Warning	ARX	Grant	22 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 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.