Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 68, NWS Milwaukee, WI

September 7, 20214 counties in Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Sep 7, 2021, 11:01 AM CDT for 4 counties in Wisconsin. It was in force for 59 min. 4 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, 11:01 AM CDT (16:01 UTC)
Expired
Sep 7, 2021, 12:00 PM CDT
In force
59 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Columbia County, WI, Dane County, WI, Dodge County, WI, Jefferson County, WI

The radar

The Milwaukee radar (KMKX), 34 km from the middle of the area, began a volume at 16:00 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

TimeReportWhereRemark
Sep 7, 11:08 AM CDTHAIL 1Mcfarland, WITIME ESTIMATED FROM RADAR.
Sep 7, 11:10 AM CDTHAIL 1Fitchburg, WI
Sep 7, 11:22 AM CDTHAIL 1Stoughton, WISPOTTER REPORTED QUARTER SIZE HAIL IN STOUGHTON.
Sep 7, 11:24 AM CDTHAIL 12 Wsw Watertown, WI

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 4.0 hours before the alert went out and 169 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-pSkew-T log-p diagram, Green Bay/Straub, WI at 12:00Z on 2021-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 14 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 12:00Z on 2021-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -120 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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.

894 
WUUS53 KMKX 071601
SVRMKX
WIC021-025-027-055-071700-
/O.NEW.KMKX.SV.W.0068.210907T1601Z-210907T1700Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
1101 AM CDT Tue Sep 7 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Southeastern Columbia County in south central Wisconsin...
  Eastern Dane County in south central Wisconsin...
  Jefferson County in southeastern Wisconsin...
  Southern Dodge County in southeastern Wisconsin...

* Until noon CDT.

* At 1100 AM CDT, severe thunderstorms were located along a line
  extending from 6 miles north of Sun Prairie to near New Glarus,
  moving east at 60 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Severe thunderstorms will be near...
  Sun Prairie around 1105 AM CDT.
  Columbus, Marshall and Waterloo around 1110 AM CDT.
  Oregon and Brooklyn around 1115 AM CDT.
  Watertown and Stoughton around 1125 AM CDT.
  Edgerton around 1135 AM CDT.
  Lake Koshkonong around 1140 AM CDT.
  Whitewater around 1150 AM CDT.
  Palmyra around 1155 AM CDT.

Other locations impacted by these severe thunderstorms include
Busseyville, Richwood, Hubbleton, Utica, Rockdale, Rome, Token Creek,
Henry Vilas Zoo, Hebron and Helenville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4286 8974 4334 8916 4332 8842 4320 8842
      4320 8854 4284 8855
TIME...MOT...LOC 1600Z 272DEG 54KT 4327 8920 4285 8970 

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

$$

GEHRING
2 follow-up statements
260 
WWUS53 KMKX 071616 RRA
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
1116 AM CDT Tue Sep 7 2021

WIC021-071626-
/O.CAN.KMKX.SV.W.0068.000000T0000Z-210907T1700Z/
Columbia WI-
1116 AM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN COLUMBIA COUNTY
IS CANCELLED...

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

LAT...LON 4286 8953 4332 8886 4332 8842 4320 8842
      4320 8854 4284 8855
TIME...MOT...LOC 1616Z 272DEG 54KT 4326 8891 4284 8941 

$$

WIC025-027-055-071700-
/O.CON.KMKX.SV.W.0068.000000T0000Z-210907T1700Z/
Dane WI-Jefferson WI-Dodge WI-
1116 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL NOON CDT FOR
SOUTHEASTERN DANE...JEFFERSON AND SOUTHERN DODGE COUNTIES...

At 1116 AM CDT, severe thunderstorms were located along a line
extending from 6 miles northeast of Waterloo to Brooklyn, moving east
at 60 mph.

HAZARD...Quarter size hail.

SOURCE...Trained weather spotters.

IMPACT...Damage to vehicles is expected.

These severe storms will be near...
  Watertown and Stoughton around 1125 AM CDT.
  Edgerton around 1135 AM CDT.
  Lake Koshkonong around 1140 AM CDT.
  Whitewater around 1150 AM CDT.
  Palmyra around 1155 AM CDT.

Other locations impacted by these severe thunderstorms include
Busseyville, Ashippun, Milford, Richwood, Ixonia, Hubbleton, Utica,
Rockdale, Lebanon and Pipersville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4286 8953 4332 8886 4332 8842 4320 8842
      4320 8854 4284 8855
TIME...MOT...LOC 1616Z 272DEG 54KT 4326 8891 4284 8941 

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

$$

GEHRING
432 
WWUS53 KMKX 071658
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
1158 AM CDT Tue Sep 7 2021

WIC025-027-055-071706-
/O.EXP.KMKX.SV.W.0068.000000T0000Z-210907T1700Z/
Dane WI-Jefferson WI-Dodge WI-
1158 AM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DANE...JEFFERSON
AND SOUTHERN DODGE COUNTIES WILL EXPIRE AT NOON CDT...
    
The storms which prompted the warning have moved out of much of the 
area. Therefore, the warning will be allowed to expire. A seperate 
Severe Thunderstorm Warning continues for far southeast Jefferson 
County for large hail. 

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

LAT...LON 4286 8953 4332 8886 4332 8842 4320 8842
      4320 8854 4284 8855
TIME...MOT...LOC 1656Z 272DEG 54KT 4324 8812 4282 8862 

$$

GEHRING

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 9:06 PM CDTSmall Craft AdvisoryMKX45 hr
Sep 7, 2:21 AM CDTGale WarningMKX13 hr
Sep 7, 8:41 AM CDTSpecial Weather StatementMKXMarquette49 min
Sep 7, 8:57 AM CDTSevere Thunderstorm WarningMKXGreen Lake, Marquette48 min
Sep 7, 9:34 AM CDTSevere Thunderstorm WarningMKXFond du Lac56 min
Sep 7, 10:10 AM CDTSevere Thunderstorm WarningMKXFond du Lac50 min
Sep 7, 10:27 AM CDTSevere Thunderstorm WarningMKXFond du Lac, Sheboygan78 min
Sep 7, 10:40 AM CDTSpecial Weather StatementMKXColumbia, Dane, Dodge, Iowa65 min
Sep 7, 10:57 AM CDTSpecial Marine WarningMKX63 min
Sep 7, 11:04 AM CDTSevere Thunderstorm WarningMKXDodge, Fond du Lac, Ozaukee, Sheboygan, Washington56 min
Sep 7, 11:11 AM CDTSevere Thunderstorm WarningMKXGreen, Rock34 min
Sep 7, 11:22 AM CDTSpecial Marine WarningMKX53 min
Sep 7, 11:27 AM CDTSevere Thunderstorm WarningMKXMilwaukee, Ozaukee, Washington, Waukesha48 min
Sep 7, 11:31 AM CDTSpecial Marine WarningMKX89 min
Sep 7, 11:42 AM CDTSevere Thunderstorm WarningMKXRock, Walworth48 min
Sep 7, 11:45 AM CDTSevere Thunderstorm WarningMKXJefferson, Milwaukee, Waukesha60 min
Sep 7, 12:18 PM CDTSpecial Marine WarningMKX87 min
Sep 7, 12:19 PM CDTSevere Thunderstorm WarningMKXRacine, Walworth40 min
Sep 7, 12:30 PM CDTSevere Thunderstorm WarningMKXKenosha, Racine, Rock, Walworth60 min
Sep 7, 12:47 PM CDTSpecial Weather StatementMKXMilwaukee28 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021Every 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.