Alert archive / Wisconsin / Tornado Warnings in 2021

Tornado Warning 18, NWS La Crosse, WI

September 20, 2021Buffalo County, Trempealeau County, Wisconsin

NWS La Crosse, WI issued this tornado warning at Sep 20, 2021, 5:46 PM CDT for Buffalo County, Trempealeau County, Wisconsin. It was in force for 29 min. 7 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: Sep 20, 2021, 5:46 PM CDT (22:46 UTC)
Expired: Sep 20, 2021, 6:15 PM CDT
In force: 29 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Buffalo County, WI, Trempealeau County, WI

The radar

The La Crosse radar (KARX), 77 km from the middle of the area, began a volume at 22:50 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
Sep 20, 5:47 PM CDT	TSTM WND GST 70	Independence, WI
Sep 20, 6:00 PM CDT	TSTM WND DMG	1 Sse Chimney Rock, WI	SEMI BLOWN OVER AT THE INTERSECTION OF STATE HIGHWAY 93 AND COUNTY ROAD VV.
Sep 20, 6:00 PM CDT	TORNADO	1 Sse Chimney Rock, WI	SEMI BLOWN OVER AT THE INTERSECTION OF STATE HIGHWAY 93 AND COUNTY ROAD VV.
Sep 20, 6:03 PM CDT	TSTM WND DMG	3 Ne Chimney Rock, WI	DAMAGE TO A PORCH AND 4 SEASON ROOM AT A RESIDENCE. POLE BARN ALSO DESTROYED.
Sep 20, 6:03 PM CDT	TSTM WND DMG	3 Ne Chimney Rock, WI	LOTS OF DEBRIS ON COUNTY ROAD D SOUTH OF STRUM WITH A HOUSE POSSIBLE SUSTAINING DAMAGE.
Sep 20, 6:03 PM CDT	TORNADO	3 Ne Chimney Rock, WI	DAMAGE TO A PORCH AND 4 SEASON ROOM AT A RESIDENCE. POLE BARN ALSO DESTROYED.
Sep 20, 6:03 PM CDT	TORNADO	3 Ne Chimney Rock, WI	LOTS OF DEBRIS ON COUNTY ROAD D SOUTH OF STRUM WITH A HOUSE POSSIBLE SUSTAINING DAMAGE.

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
Sep 20, 2:07 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.8 hours before the alert went out and 181 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: 148 J/kg
Mixed-layer CIN: -141 J/kg
Mixed-layer LCL: 1002 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 210 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted.

362 
WFUS53 KARX 202246
TORARX
WIC011-121-202315-
/O.NEW.KARX.TO.W.0018.210920T2246Z-210920T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service La Crosse WI
546 PM CDT Mon Sep 20 2021

The National Weather Service in La Crosse has issued a

* Tornado Warning for...
  East central Buffalo County in west central Wisconsin...
  Northern Trempealeau County in west central Wisconsin...

* Until 615 PM CDT.

* At 546 PM CDT, severe thunderstorms capable of producing both
  tornadoes and extensive straight line wind damage were located near
  Independence, or 7 miles north of Arcadia, moving northeast at 50
  mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* These dangerous storms will be near...
  Independence around 550 PM CDT.
  Strum around 605 PM CDT.
  Osseo around 610 PM CDT.

Other locations impacted by this tornadic thunderstorm include The
Borst Valley Area, Eleva, Pleasantville, Chimney Rock, Highway 53 And
County E, Wickham Valley and Walek Knob.

This includes Interstate 94 between mile markers 88 and 90.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4458 9116 4423 9151 4441 9165 4460 9152
      4460 9117
TIME...MOT...LOC 2246Z 220DEG 46KT 4435 9153 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Skow

3 follow-up statements

197 
WWUS53 KARX 202254
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
554 PM CDT Mon Sep 20 2021

WIC011-202303-
/O.CAN.KARX.TO.W.0018.000000T0000Z-210920T2315Z/
Buffalo WI-
554 PM CDT Mon Sep 20 2021

...THE TORNADO WARNING FOR EAST CENTRAL BUFFALO COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
west central Wisconsin.

LAT...LON 4428 9146 4444 9153 4459 9146 4460 9117
      4458 9116
TIME...MOT...LOC 2253Z 220DEG 46KT 4443 9144 

$$

WIC121-202315-
/O.CON.KARX.TO.W.0018.000000T0000Z-210920T2315Z/
Trempealeau WI-
554 PM CDT Mon Sep 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR NORTHERN
TREMPEALEAU COUNTY...

At 553 PM CDT, a severe squall line capable of producing both
tornadoes and extensive straight line wind damage was located near
Independence, or 7 miles northwest of Whitehall, moving northeast at
55 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

These dangerous storms will be near...
  Strum around 605 PM CDT.
  Osseo around 610 PM CDT.

Other locations impacted by this tornadic thunderstorm include The
Borst Valley Area, Pleasantville, Chimney Rock, Highway 53 And County
E, Walek Knob, Elk Creek and Eleva.

This includes Interstate 94 between mile markers 88 and 90.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4428 9146 4444 9153 4459 9146 4460 9117
      4458 9116
TIME...MOT...LOC 2253Z 220DEG 46KT 4443 9144 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Skow

130 
WWUS53 KARX 202259
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
559 PM CDT Mon Sep 20 2021

WIC121-202315-
/O.CON.KARX.TO.W.0018.000000T0000Z-210920T2315Z/
Trempealeau WI-
559 PM CDT Mon Sep 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR NORTHERN
TREMPEALEAU COUNTY...
        
At 559 PM CDT, a confirmed tornado was located near Independence, or
8 miles northwest of Whitehall, moving northeast at 50 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornado will be near...
  Strum around 610 PM CDT.
  Osseo around 615 PM CDT.

Other locations impacted by this tornadic thunderstorm include The
Borst Valley Area, Pleasantville, Chimney Rock, Highway 53 And County
E, Walek Knob, Elk Creek and Eleva.

This includes Interstate 94 between mile markers 88 and 90.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4434 9141 4444 9153 4459 9146 4460 9117
      4458 9116
TIME...MOT...LOC 2259Z 218DEG 41KT 4445 9143 

TORNADO...OBSERVED
MAX HAIL SIZE...<.75 IN

$$

Skow

543 
WWUS53 KARX 202303
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
603 PM CDT Mon Sep 20 2021

WIC121-202315-
/O.CON.KARX.TO.W.0018.000000T0000Z-210920T2315Z/
Trempealeau WI-
603 PM CDT Mon Sep 20 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 615 PM CDT FOR
NORTHEASTERN TREMPEALEAU COUNTY...
        
At 603 PM CDT, a confirmed tornado was located near Strum, or 9 miles
northwest of Whitehall, moving northeast at 40 mph.

HAZARD...Damaging tornado.

SOURCE...Radar confirmed tornado.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornado will be near...
  Strum around 610 PM CDT.
  Osseo around 620 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Chimney Rock and Elk Creek.

This includes Interstate 94 between mile markers 88 and 90.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

This cluster of thunderstorms is capable of producing tornadoes and
widespread significant wind damage. Do not wait to see or hear the
tornado. For your protection move to an interior room on the lowest
floor of a building.

&&

LAT...LON 4441 9137 4446 9149 4458 9146 4459 9146
      4460 9117 4458 9116
TIME...MOT...LOC 2303Z 216DEG 33KT 4448 9141 

TORNADO...OBSERVED
MAX HAIL SIZE...<.75 IN

$$

Skow

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 20, 5:12 PM CDT	Special Weather Statement	ARX	Buffalo	33 min
Sep 20, 5:38 PM CDT	Special Weather Statement	ARX	La Crosse, Trempealeau	37 min
Sep 20, 6:11 PM CDT	Tornado Warning Tornado observed	ARX	Clark, Trempealeau	19 min
Sep 20, 6:18 PM CDT	Special Weather Statement	ARX	Jackson, La Crosse, Monroe, Vernon	42 min

Nearby

Tornado Warnings in Wisconsin, 2021 Every tornado warning in 2021 Tornadoes 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.