Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 76, NWS Milwaukee, WI

September 12, 2021Dodge County, Washington County, Waukesha County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Sep 12, 2021, 3:42 PM CDT for Dodge County, Washington County, Waukesha County, Wisconsin. It was in force for 33 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 12, 2021, 3:42 PM CDT (20:42 UTC)
Expired
Sep 12, 2021, 4:15 PM CDT
In force
33 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Dodge County, WI, Washington County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 43 km from the middle of the area, began a volume at 20:42 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 12, 4:09 PM CDTHAIL 0.751 S Germantown, WIREPORT FROM MPING: DIME (0.75 IN.).
Sep 12, 4:10 PM CDTHAIL 0.75Menomonee Falls, WITIME ESTIMATED FROM RADAR.
Sep 12, 4:10 PM CDTHAIL 0.75Menomonee Falls, WI
Sep 12, 4:10 PM CDTHAIL 13 Nne Lannon, WITIME ESTIMATED FROM RADAR.
Sep 12, 4:10 PM CDTHAIL 13 Nne Lannon, WI
Sep 12, 4:10 PM CDTHAIL 1Germantown, WITIME ESTIMATED FROM RADAR.
Sep 12, 4:11 PM CDTHAIL 0.752 Se Germantown, WIREPORT FROM MPING: DIME (0.75 IN.).

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, 8.7 hours before the alert went out and 132 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 2021-09-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-09-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1526 m above ground
0-6 km bulk shear
59 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
173 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

664 
WUUS53 KMKX 122042
SVRMKX
WIC027-131-133-122115-
/O.NEW.KMKX.SV.W.0076.210912T2042Z-210912T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
342 PM CDT Sun Sep 12 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Northeastern Waukesha County in southeastern Wisconsin...
  Southern Washington County in southeastern Wisconsin...
  Southeastern Dodge County in southeastern Wisconsin...

* Until 415 PM CDT.

* At 341 PM CDT, a severe thunderstorm was located near Lac La Belle,
  or 8 miles east of Watertown, moving east at 45 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Menomonee Falls, Hartford, Sussex, Jackson, Slinger, Germantown,
  Lannon, Richfield, Ashippun, Rubicon, Lebanon, Neosho, Colgate,
  Holy Hill, Kirchhayn, Monches, Keowns and Hubertus.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4337 8804 4337 8806 4313 8807 4320 8854
      4320 8869 4331 8869 4341 8804
TIME...MOT...LOC 2041Z 264DEG 39KT 4324 8856 

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

$$

DDV
1 follow-up statement
786 
WWUS53 KMKX 122055
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
355 PM CDT Sun Sep 12 2021

WIC027-122104-
/O.CAN.KMKX.SV.W.0076.000000T0000Z-210912T2115Z/
Dodge WI-
355 PM CDT Sun Sep 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN DODGE COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4337 8804 4337 8806 4313 8807 4318 8842
      4335 8842 4341 8804
TIME...MOT...LOC 2054Z 264DEG 39KT 4326 8836 

$$

WIC131-133-122115-
/O.CON.KMKX.SV.W.0076.000000T0000Z-210912T2115Z/
Waukesha WI-Washington WI-
355 PM CDT Sun Sep 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM CDT
FOR NORTHEASTERN WAUKESHA AND SOUTHERN WASHINGTON COUNTIES...

At 354 PM CDT, a severe thunderstorm was located near Hartford,
moving east at 45 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Menomonee Falls, Hartford, Sussex, Jackson, Slinger, Germantown,
Lannon, Richfield, Colgate, Holy Hill, Kirchhayn, Monches, Keowns and
Hubertus.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4337 8804 4337 8806 4313 8807 4318 8842
      4335 8842 4341 8804
TIME...MOT...LOC 2054Z 264DEG 39KT 4326 8836 

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

$$

DDV

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 12, 3:32 PM CDTSpecial Weather StatementMKXWashington, Waukesha43 min
Sep 12, 3:59 PM CDTSevere Thunderstorm WarningMKXMilwaukee, Ozaukee33 min
Sep 12, 4:00 PM CDTSpecial Marine WarningMKX60 min
Sep 12, 4:15 PM CDTSpecial Weather StatementMKXOzaukee30 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.