Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 75, NWS Milwaukee, WI

September 7, 20214 counties in Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Sep 7, 2021, 12:30 PM CDT for 4 counties in Wisconsin. It was in force for 60 min. 10 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 7, 2021, 12:30 PM CDT (17:30 UTC)
Expired: Sep 7, 2021, 1:30 PM CDT
In force: 60 min
Issued by: NWS Milwaukee, WI
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Kenosha County, WI, Racine County, WI, Rock County, WI, Walworth County, WI

The radar

The Milwaukee radar (KMKX), 51 km from the middle of the area, began a volume at 17:34 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 7, 12:32 PM CDT	HAIL 1	Delavan, WI
Sep 7, 12:32 PM CDT	HAIL 1.25	Delavan, WI	CORRECTS PREVIOUS HAIL REPORT FROM DELAVAN. 1.0 TO 1.25 INCH HAIL REPORTED BY TRAINED SPOTTER.
Sep 7, 12:33 PM CDT	HAIL 1.5	1 N Delavan, WI	MULTIPLE REPORTS OF 1.0 TO 1.5 INCH HAIL REPORTED AROUND DELAVAN WI.
Sep 7, 12:35 PM CDT	HAIL 1	4 Wsw Clinton, WI
Sep 7, 12:42 PM CDT	HAIL 1	Elkhorn, WI
Sep 7, 12:44 PM CDT	HAIL 1	1 Nne Como, WI
Sep 7, 12:44 PM CDT	HAIL 1.5	Williams Bay, WI	PENNY SIZE TO PING PONG BALL SIZE. TIME ESTIMATED FROM RADAR.
Sep 7, 12:46 PM CDT	HAIL 1	1 S Como, WI
Sep 7, 12:48 PM CDT	HAIL 0.75	Lake Geneva, WI
Sep 7, 12:48 PM CDT	HAIL 1	1 Nnw Walworth, 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
Sep 7, 11:21 AM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 5.5 hours before the alert went out and 210 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: 14 J/kg
Mixed-layer CIN: -216 J/kg
Mixed-layer LCL: 1012 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: -120 m²/s²
0-3 km storm-relative helicity: 35 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

799 
WUUS53 KMKX 071730
SVRMKX
WIC059-101-105-127-071830-
/O.NEW.KMKX.SV.W.0075.210907T1730Z-210907T1830Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
1230 PM CDT Tue Sep 7 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Southern Walworth County in southeastern Wisconsin...
  Southeastern Rock County in south central Wisconsin...
  Southern Racine County in southeastern Wisconsin...
  Kenosha County in southeastern Wisconsin...

* Until 130 PM CDT.

* At 1229 PM CDT, severe thunderstorms were located along a line
  extending from near Elkhorn to near South Beloit, moving east at 60
  mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Kenosha, Racine, Beloit, Mount Pleasant, Pleasant Prairie, Elkhorn,
  Delavan, Lake Geneva, Sturtevant, Union Grove, Paddock Lake,
  Williams Bay, Camp Lake, Winthrop Harbor, Wheatland, Genoa City,
  Walworth, Silver Lake, Clinton and Fontana-On-Geneva Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4250 8934 4270 8871 4270 8778 4267 8779
      4266 8781 4261 8782 4255 8781 4252 8781
      4249 8780
TIME...MOT...LOC 1729Z 271DEG 51KT 4269 8847 4249 8908 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

GEHRING

4 follow-up statements

484 
WWUS53 KMKX 071739
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
1239 PM CDT Tue Sep 7 2021

WIC059-101-105-127-071830-
/O.CON.KMKX.SV.W.0075.000000T0000Z-210907T1830Z/
Walworth WI-Rock WI-Racine WI-Kenosha WI-
1239 PM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM CDT
FOR SOUTHERN WALWORTH...SOUTHEASTERN ROCK...SOUTHERN RACINE AND
KENOSHA COUNTIES...

At 1238 PM CDT, severe thunderstorms were located along a line
extending from near Bohners Lake to near South Beloit, moving east at
60 mph. Quarter size hail was reported in Delavan with this storm. 

HAZARD...Quarter size hail.

SOURCE...Trained weather spotters.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Kenosha, Racine, Beloit, Mount Pleasant, Pleasant Prairie, Elkhorn,
Delavan, Lake Geneva, Sturtevant, Union Grove, Paddock Lake, Williams
Bay, Camp Lake, Winthrop Harbor, Wheatland, Genoa City, Walworth,
Silver Lake, Clinton and Fontana-On-Geneva Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4250 8934 4270 8871 4270 8778 4267 8779
      4266 8781 4261 8782 4255 8781 4252 8781
      4249 8780
TIME...MOT...LOC 1738Z 271DEG 51KT 4269 8836 4249 8897 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

GEHRING

191 
WWUS53 KMKX 071754
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
1254 PM CDT Tue Sep 7 2021

WIC105-071803-
/O.CAN.KMKX.SV.W.0075.000000T0000Z-210907T1830Z/
Rock WI-
1254 PM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ROCK 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 600 PM CDT for
southeastern Wisconsin.

LAT...LON 4250 8876 4270 8839 4270 8778 4267 8779
      4266 8781 4261 8782 4255 8781 4252 8781
      4249 8780
TIME...MOT...LOC 1753Z 270DEG 46KT 4269 8815 4248 8860 

$$

WIC059-101-127-071830-
/O.CON.KMKX.SV.W.0075.000000T0000Z-210907T1830Z/
Walworth WI-Racine WI-Kenosha WI-
1254 PM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM CDT
FOR SOUTHEASTERN WALWORTH...SOUTHERN RACINE AND KENOSHA COUNTIES...

At 1253 PM CDT, severe thunderstorms were located along a line 
extending from Eagle Lake to near Walworth, moving east at 55 mph. 
Quarter size was reported in Lake Geneva. 

HAZARD...Quarter size hail.

SOURCE...Trained weather spotters.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Kenosha, Racine, Mount Pleasant, Pleasant Prairie, Lake Geneva,
Sturtevant, Union Grove, Paddock Lake, Williams Bay, Camp Lake,
Wheatland, Genoa City, Walworth, Silver Lake, Fontana-On-Geneva Lake,
Channel Lake, Sharon, Lake Catherine, Powers Lake and Browns Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4250 8876 4270 8839 4270 8778 4267 8779
      4266 8781 4261 8782 4255 8781 4252 8781
      4249 8780
TIME...MOT...LOC 1753Z 270DEG 46KT 4269 8815 4248 8860 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

GEHRING

686 
WWUS53 KMKX 071816
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
116 PM CDT Tue Sep 7 2021

WIC101-127-071825-
/O.CAN.KMKX.SV.W.0075.000000T0000Z-210907T1830Z/
Walworth WI-Racine WI-
116 PM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WALWORTH AND
SOUTHERN RACINE COUNTIES IS CANCELLED...

The storms which prompted the warning have weakened or moved out of 
the warned area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 600 PM CDT for
southeastern Wisconsin.

LAT...LON 4261 8830 4261 8819 4267 8818 4267 8787
      4266 8781 4261 8782 4255 8781 4252 8781
      4249 8780 4250 8831
TIME...MOT...LOC 1815Z 271DEG 51KT 4268 8779 4248 8824 

$$

WIC059-071830-
/O.CON.KMKX.SV.W.0075.000000T0000Z-210907T1830Z/
Kenosha WI-
116 PM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 130 PM CDT
FOR KENOSHA COUNTY...

At 115 PM CDT, severe thunderstorms were located along a line 
extending from north of Kenosha to near Spring Grove, moving east at 
55 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Kenosha, Pleasant Prairie, Paddock Lake, Camp Lake, Wheatland, Silver
Lake, Powers Lake, Twin Lakes, Genoa City, Salem, Bristol, Paris,
Brighton, Somers, Bassett, New Munster and Slades Corners.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4261 8830 4261 8819 4267 8818 4267 8787
      4266 8781 4261 8782 4255 8781 4252 8781
      4249 8780 4250 8831
TIME...MOT...LOC 1815Z 271DEG 51KT 4268 8779 4248 8824 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

GEHRING

715 
WWUS53 KMKX 071826
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
126 PM CDT Tue Sep 7 2021

WIC059-071835-
/O.EXP.KMKX.SV.W.0075.000000T0000Z-210907T1830Z/
Kenosha WI-
126 PM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR KENOSHA COUNTY WILL EXPIRE AT
130 PM CDT...
            
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 will be allowed to expire.  However small hail
is still possible with these thunderstorms.



LAT...LON 4261 8830 4261 8819 4267 8818 4267 8787
      4266 8781 4261 8782 4255 8781 4252 8781
      4249 8780 4250 8831
TIME...MOT...LOC 1825Z 271DEG 51KT 4268 8761 4248 8806 

$$

GEHRING

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 6, 9:06 PM CDT	Small Craft Advisory	MKX		45 hr
Sep 7, 2:21 AM CDT	Gale Warning	MKX		13 hr
Sep 7, 8:41 AM CDT	Special Weather Statement	MKX	Marquette	49 min
Sep 7, 8:57 AM CDT	Severe Thunderstorm Warning	MKX	Green Lake, Marquette	48 min
Sep 7, 9:34 AM CDT	Severe Thunderstorm Warning	MKX	Fond du Lac	56 min
Sep 7, 10:10 AM CDT	Severe Thunderstorm Warning	MKX	Fond du Lac	50 min
Sep 7, 10:27 AM CDT	Severe Thunderstorm Warning	MKX	Fond du Lac, Sheboygan	78 min
Sep 7, 10:40 AM CDT	Special Weather Statement	MKX	Columbia, Dane, Dodge, Iowa	65 min
Sep 7, 10:57 AM CDT	Special Marine Warning	MKX		63 min
Sep 7, 11:01 AM CDT	Severe Thunderstorm Warning	MKX	Columbia, Dane, Dodge, Jefferson	59 min
Sep 7, 11:04 AM CDT	Severe Thunderstorm Warning	MKX	Dodge, Fond du Lac, Ozaukee, Sheboygan, Washington	56 min
Sep 7, 11:11 AM CDT	Severe Thunderstorm Warning	MKX	Green, Rock	34 min
Sep 7, 11:22 AM CDT	Special Marine Warning	MKX		53 min
Sep 7, 11:27 AM CDT	Severe Thunderstorm Warning	MKX	Milwaukee, Ozaukee, Washington, Waukesha	48 min
Sep 7, 11:31 AM CDT	Special Marine Warning	MKX		89 min
Sep 7, 11:42 AM CDT	Severe Thunderstorm Warning	MKX	Rock, Walworth	48 min
Sep 7, 11:45 AM CDT	Severe Thunderstorm Warning	MKX	Jefferson, Milwaukee, Waukesha	60 min
Sep 7, 12:18 PM CDT	Special Marine Warning	MKX		87 min
Sep 7, 12:19 PM CDT	Severe Thunderstorm Warning	MKX	Racine, Walworth	40 min
Sep 7, 12:47 PM CDT	Special Weather Statement	MKX	Milwaukee	28 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.