Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 46, NWS Milwaukee, WI

August 10, 20217 counties in Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 10, 2021, 6:08 PM CDT for 7 counties in Wisconsin. It was in force for 97 min. 18 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: Aug 10, 2021, 6:08 PM CDT (23:08 UTC)
Expired: Aug 10, 2021, 7:45 PM CDT
In force: 97 min
Issued by: NWS Milwaukee, WI
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Dodge County, WI, Jefferson County, WI, Kenosha County, WI, Racine County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 13 km from the middle of the area, began a volume at 23:10 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 10, 6:35 PM CDT	TSTM WND GST 52	2 Ene East Troy, WI	57C.
Aug 10, 6:40 PM CDT	TSTM WND DMG	1 E Whitewater, WI	LARGE BRANCHES DOWN ACROSS EASTERN PORTION OF TOWN.
Aug 10, 6:50 PM CDT	TSTM WND GST 68	3 Sw Eagle, WI
Aug 10, 6:55 PM CDT	TSTM WND DMG	2 Se Eagle, WI	LARGE TREE FELL ON HOUSE AND CASUED SIGNIFICANT DAMAGE.
Aug 10, 6:55 PM CDT	TSTM WND DMG	Eagle, WI	LARGE LIMBS DOWN...POWER OUT AND 0.75 INCH HAIL.
Aug 10, 6:58 PM CDT	TSTM WND GST 77	3 Se Eagle, WI	LARGE TREES SNAPPED AND UPROOTED.
Aug 10, 7:00 PM CDT	TSTM WND GST 60	Pell Lake, WI	BLOOMFIELD...NO POWER.
Aug 10, 7:03 PM CDT	TSTM WND GST 54	4 Sse Sullivan, WI	AT WFO MKX.
Aug 10, 7:05 PM CDT	TSTM WND DMG	2 Wsw Dousman, WI	LARGE BRANCHES DOWN ACROSS THE ROAD.
Aug 10, 7:05 PM CDT	TSTM WND DMG	4 E Allenton, WI	SMALL GARDEN SHED DESTROYED.
Aug 10, 7:07 PM CDT	TSTM WND DMG	1 Sse Waukesha, WI	DAMAGE TO A BUSINESS MARQUEE SIGN...KNOCKED OVER.
Aug 10, 7:10 PM CDT	TSTM WND DMG	1 Sse West Bend, WI	ORNAMENTAL TREE UPROOTED...PIC SHARED VIA SOCIAL MEDIA.
Aug 10, 7:10 PM CDT	TSTM WND GST 60	1 S Oconomowoc, WI	EST 50-60 MPH GUSTS.
Aug 10, 7:15 PM CDT	TSTM WND DMG	Brookfield, WI	LARGE TREE SNAPPED.
Aug 10, 7:15 PM CDT	TSTM WND GST 44	3 E West Bend, WI
Aug 10, 7:15 PM CDT	TSTM WND GST 47	2 N Waukesha, WI	UES.
Aug 10, 7:15 PM CDT	TSTM WND GST 52	2 Nw Burlington, WI	BUU.
Aug 10, 7:19 PM CDT	TSTM WND GST 55	1 Se Germantown, 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 10, 3:47 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 11.1 hours before the alert went out and 162 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: 32 J/kg
Mixed-layer CIN: -550 J/kg
Mixed-layer LCL: 828 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 42 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

373 
WUUS53 KMKX 102308
SVRMKX
WIC027-055-059-101-127-131-133-110045-
/O.NEW.KMKX.SV.W.0046.210810T2308Z-210811T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
608 PM CDT Tue Aug 10 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Walworth County in southeastern Wisconsin...
  Western Racine County in southeastern Wisconsin...
  Waukesha County in southeastern Wisconsin...
  Washington County in southeastern Wisconsin...
  Eastern Jefferson County in southeastern Wisconsin...
  Eastern Dodge County in southeastern Wisconsin...
  Western Kenosha County in southeastern Wisconsin...

* Until 745 PM CDT.

* At 608 PM CDT, severe thunderstorms were located along a line
  extending from Randolph to near Beloit, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Waukesha, West Allis, Wauwatosa, New Berlin, Brookfield, Menomonee
  Falls, West Bend, Muskego, Whitewater, Hartford, Pewaukee, Sussex,
  Elkhorn, Hartland, Delavan, Hales Corners, Lake Geneva, Mukwonago,
  Delafield and Jackson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4283 8878 4284 8870 4363 8861 4363 8841
      4354 8840 4354 8804 4284 8807 4284 8811
      4250 8811 4249 8877
TIME...MOT...LOC 2308Z 267DEG 35KT 4356 8908 4252 8910 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KAVINSKY

4 follow-up statements

816 
WWUS53 KMKX 110003
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
703 PM CDT Tue Aug 10 2021

WIC027-055-059-101-127-131-133-110045-
/O.CON.KMKX.SV.W.0046.000000T0000Z-210811T0045Z/
Walworth WI-Racine WI-Waukesha WI-Washington WI-Jefferson WI-
Dodge WI-Kenosha WI-
703 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR WALWORTH...WESTERN RACINE...WAUKESHA...WASHINGTON...EASTERN
JEFFERSON...EASTERN DODGE AND WESTERN KENOSHA COUNTIES...

At 702 PM CDT, severe thunderstorms were located along a line
extending from near Campbellsport to Twin Lakes, moving east at 50
mph.

HAZARD...60 mph wind gusts.

SOURCE...Trained weather spotters reported a localized wind gust to 
         77 mph near Eagle. 

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Waukesha, West Allis, Wauwatosa, New Berlin, Brookfield, Menomonee
Falls, West Bend, Muskego, Whitewater, Hartford, Pewaukee, Sussex,
Elkhorn, Hartland, Delavan, Hales Corners, Lake Geneva, Mukwonago,
Delafield and Jackson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4283 8878 4284 8870 4363 8861 4363 8841
      4354 8840 4354 8804 4284 8807 4284 8811
      4250 8811 4249 8877
TIME...MOT...LOC 0002Z 270DEG 44KT 4355 8829 4252 8824 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KAVINSKY

805 
WWUS53 KMKX 110014
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
714 PM CDT Tue Aug 10 2021

WIC027-055-059-101-127-131-133-110045-
/O.CON.KMKX.SV.W.0046.000000T0000Z-210811T0045Z/
Walworth WI-Racine WI-Waukesha WI-Washington WI-Jefferson WI-
Dodge WI-Kenosha WI-
714 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR WALWORTH...WESTERN RACINE...WAUKESHA...WASHINGTON...EASTERN
JEFFERSON...EASTERN DODGE AND WESTERN KENOSHA COUNTIES...

At 713 PM CDT, severe thunderstorms were located along a line
extending from near Kewaskum to Camp Lake, moving east at 40 mph.

HAZARD...70 mph wind gusts.

SOURCE...Trained weather spotters. Several reports of wind gusts 
         between 60 and 75mph. Trees and limbs downed.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Waukesha, West Allis, Wauwatosa, New Berlin, Brookfield, Menomonee
Falls, West Bend, Muskego, Whitewater, Hartford, Pewaukee, Sussex,
Elkhorn, Hartland, Delavan, Hales Corners, Lake Geneva, Mukwonago,
Delafield and Jackson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is an EXTREMELY DANGEROUS SITUATION. These storms are producing 
widespread wind damage across Waukesha county. SEEK SHELTER NOW 
inside a sturdy structure and stay away from windows.

&&

LAT...LON 4283 8878 4284 8870 4363 8861 4363 8841
      4354 8840 4354 8804 4284 8807 4284 8811
      4250 8811 4249 8877
TIME...MOT...LOC 0013Z 267DEG 35KT 4355 8818 4252 8814 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

GAGAN

670 
WWUS53 KMKX 110029
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
729 PM CDT Tue Aug 10 2021

WIC027-055-110037-
/O.CAN.KMKX.SV.W.0046.000000T0000Z-210811T0045Z/
Jefferson WI-Dodge WI-
729 PM CDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN JEFFERSON AND EASTERN
DODGE COUNTIES 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 1000 PM CDT for
southeastern Wisconsin.

LAT...LON 4284 8852 4295 8854 4319 8852 4319 8841
      4354 8839 4354 8804 4284 8807 4284 8811
      4250 8811 4250 8854
TIME...MOT...LOC 0027Z 267DEG 35KT 4356 8802 4253 8798 

$$

WIC059-101-127-131-133-110045-
/O.CON.KMKX.SV.W.0046.000000T0000Z-210811T0045Z/
Walworth WI-Racine WI-Waukesha WI-Washington WI-Kenosha WI-
729 PM CDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM CDT
FOR EASTERN WALWORTH...WESTERN RACINE...WAUKESHA...WASHINGTON AND
WESTERN KENOSHA COUNTIES...

At 727 PM CDT, severe thunderstorms were located along a line
extending from near Random Lake to near Pleasant Prairie, moving east
at 40 mph.

HAZARD...70 mph wind gusts.

SOURCE...Trained weather spotters reported trees down in Waukesha 
         County. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Waukesha, West Allis, Wauwatosa, New Berlin, Brookfield, Menomonee
Falls, West Bend, Muskego, Hartford, Pewaukee, Sussex, Elkhorn,
Hartland, Hales Corners, Lake Geneva, Mukwonago, Delafield, Jackson,
Elm Grove and Slinger.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This is an EXTREMELY DANGEROUS SITUATION. These storms are producing 
widespread wind damage across the warned area. SEEK SHELTER NOW 
inside a sturdy structure and stay away from windows.

&&

LAT...LON 4284 8852 4295 8854 4319 8852 4319 8841
      4354 8839 4354 8804 4284 8807 4284 8811
      4250 8811 4250 8854
TIME...MOT...LOC 0027Z 267DEG 35KT 4356 8802 4253 8798 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

KAVINSKY

500 
WWUS53 KMKX 110038
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
738 PM CDT Tue Aug 10 2021

WIC059-101-127-131-133-110048-
/O.EXP.KMKX.SV.W.0046.000000T0000Z-210811T0045Z/
Walworth WI-Racine WI-Waukesha WI-Washington WI-Kenosha WI-
738 PM CDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN WALWORTH...WESTERN
RACINE...WAUKESHA...WASHINGTON AND WESTERN KENOSHA COUNTIES WILL
EXPIRE AT 745 PM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

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

LAT...LON 4284 8852 4295 8854 4319 8852 4319 8841
      4354 8839 4354 8804 4284 8807 4284 8811
      4250 8811 4250 8854
TIME...MOT...LOC 0038Z 270DEG 35KT 4356 8791 4253 8787 

$$

KAVINSKY

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 7:13 PM CDT	Marine Dense Fog Advisory	MKX		14 hr
Aug 10, 2:16 PM CDT	Heat Advisory	MKX	Dane, Dodge, Green, Iowa, Jefferson, Kenosha and 8 more	29 hr
Aug 10, 4:02 PM CDT	Severe Thunderstorm Warning	MKX	Dane, Iowa, Lafayette, Sauk	73 min
Aug 10, 4:25 PM CDT	Severe Thunderstorm Warning	MKX	Iowa, Lafayette	80 min
Aug 10, 5:08 PM CDT	Severe Thunderstorm Warning	MKX	Columbia, Dane, Green, Iowa, Sauk	67 min
Aug 10, 5:36 PM CDT	Special Weather Statement	MKX	Rock	39 min
Aug 10, 5:42 PM CDT	Severe Thunderstorm Warning	MKX	Dane, Dodge, Jefferson, Rock	78 min
Aug 10, 6:12 PM CDT	Severe Thunderstorm Warning	MKX	Columbia, Dane	20 min
Aug 10, 6:24 PM CDT	Special Marine Warning	MKX		111 min
Aug 10, 6:44 PM CDT	Special Weather Statement	MKX	Fond du Lac, Sheboygan	76 min
Aug 10, 6:51 PM CDT	Severe Thunderstorm Warning	MKX	Kenosha, Milwaukee, Ozaukee, Racine	54 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.