Alert archive / Wisconsin / Tornado Warnings in 2021

Tornado Warning 12, NWS Milwaukee, WI

August 9, 2021Walworth County, Wisconsin

NWS Milwaukee, WI issued this tornado warning at Aug 9, 2021, 3:27 PM CDT for Walworth County, Wisconsin. It was in force for 29 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 9, 2021, 3:27 PM CDT (20:27 UTC)
Expired: Aug 9, 2021, 3:56 PM CDT
In force: 29 min
Issued by: NWS Milwaukee, WI
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.0 in

County Walworth County, WI

The radar

The Milwaukee radar (KMKX), 33 km from the middle of the area, began a volume at 20:31 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 nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.5 hours before the alert went out and 193 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: 1676 J/kg
Mixed-layer CIN: -63 J/kg
Mixed-layer LCL: 705 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 171 m²/s²
0-3 km storm-relative helicity: 208 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

As transmitted.

304 
WFUS53 KMKX 092027
TORMKX
WIC127-092115-
/O.NEW.KMKX.TO.W.0012.210809T2027Z-210809T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Milwaukee/Sullivan WI
327 PM CDT Mon Aug 9 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Tornado Warning for...
  Northwestern Walworth County in southeastern Wisconsin...

* Until 415 PM CDT.
    
* At 327 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Darien, or near Delavan, moving northeast at 20
  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.

* Locations impacted include...
  Elkhorn, Delavan, Abells Corners, Tibbets and Millard. 

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.

&&

LAT...LON 4261 8870 4269 8874 4280 8859 4268 8848
TIME...MOT...LOC 2027Z 241DEG 16KT 4264 8872 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

HANSEN

3 follow-up statements

537 
WWUS53 KMKX 092038
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
338 PM CDT Mon Aug 9 2021

WIC127-092115-
/O.CON.KMKX.TO.W.0012.000000T0000Z-210809T2115Z/
Walworth WI-
338 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR
NORTHWESTERN WALWORTH COUNTY...
    
At 338 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Delavan, moving northeast at 20 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.

Locations impacted include...
Elkhorn, Delavan, Abells Corners, Tibbets and Millard. 

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.

&&

LAT...LON 4261 8870 4269 8874 4280 8859 4268 8848
TIME...MOT...LOC 2038Z 241DEG 16KT 4266 8866 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

HANSEN

033 
WWUS53 KMKX 092045
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
345 PM CDT Mon Aug 9 2021

WIC127-092115-
/O.CON.KMKX.TO.W.0012.000000T0000Z-210809T2115Z/
Walworth WI-
345 PM CDT Mon Aug 9 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR CENTRAL
WALWORTH COUNTY...
    
At 344 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Delavan, moving northeast at 20 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.

Locations impacted include...
Elkhorn, Abells Corners, Tibbets and Millard. 

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.

&&

LAT...LON 4264 8866 4269 8870 4280 8859 4268 8848
TIME...MOT...LOC 2044Z 238DEG 16KT 4268 8862 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...0.00 IN

$$

HANSEN

797 
WWUS53 KMKX 092056
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
356 PM CDT Mon Aug 9 2021

WIC127-092106-
/O.CAN.KMKX.TO.W.0012.000000T0000Z-210809T2115Z/
Walworth WI-
356 PM CDT Mon Aug 9 2021

...THE TORNADO WARNING FOR CENTRAL WALWORTH COUNTY IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

LAT...LON 4264 8866 4269 8870 4280 8859 4268 8848
TIME...MOT...LOC 2054Z 241DEG 16KT 4271 8856 

$$

HANSEN

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 7:22 AM CDT	Special Weather Statement	MKX	Green	38 min
Aug 9, 1:21 PM CDT	Heat Advisory	MKX	Columbia, Dane, Dodge, Green, Iowa, Jefferson and 9 more	30 hr
Aug 9, 3:08 PM CDT	Tornado Warning Tornado observed	MKX	Rock, Walworth	37 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.