Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 54, NWS Milwaukee, WI

August 11, 2021Milwaukee County, Waukesha County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 11, 2021, 5:49 PM CDT for Milwaukee County, Waukesha County, Wisconsin. It was in force for 41 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 11, 2021, 5:49 PM CDT (22:49 UTC)
Expired
Aug 11, 2021, 6:30 PM CDT
In force
41 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Milwaukee County, WI, Waukesha County, WI

The radar

The Milwaukee radar (KMKX), 47 km from the middle of the area, began a volume at 22:49 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 10.8 hours before the alert went out and 176 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 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1499 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 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
1499 J/kg
Mixed-layer CIN
-136 J/kg
Mixed-layer LCL
678 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

482 
WUUS53 KMKX 112249
SVRMKX
WIC079-133-112330-
/O.NEW.KMKX.SV.W.0054.210811T2249Z-210811T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
549 PM CDT Wed Aug 11 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Southern Milwaukee County in southeastern Wisconsin...
  Southern Waukesha County in southeastern Wisconsin...

* Until 630 PM CDT.

* At 549 PM CDT, a severe thunderstorm was located over Mukwonago,
  moving east at 55 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Milwaukee, Waukesha, West Allis, New Berlin, Greenfield, Oak Creek,
  Muskego, South Milwaukee, Cudahy, Greendale, St. Francis, Hales
  Corners, Mukwonago, West Milwaukee, Franklin, Vernon, North
  Prairie, Big Bend, Eagle and Genesee Depot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4284 8784 4284 8850 4297 8850 4302 8790
      4299 8788 4296 8785 4288 8785 4285 8783
      4285 8782
TIME...MOT...LOC 2249Z 271DEG 48KT 4290 8836 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CMILLER
2 follow-up statements
449 
WWUS53 KMKX 112318
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
618 PM CDT Wed Aug 11 2021

WIC079-133-112330-
/O.CON.KMKX.SV.W.0054.000000T0000Z-210811T2330Z/
Milwaukee WI-Waukesha WI-
618 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM CDT
FOR SOUTHERN MILWAUKEE AND SOUTHEASTERN WAUKESHA COUNTIES...

At 618 PM CDT, a severe thunderstorm was located over South
Milwaukee, moving east at 55 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Milwaukee, Waukesha, West Allis, New Berlin, Greenfield, Oak Creek,
Muskego, South Milwaukee, Cudahy, Greendale, St. Francis, Hales
Corners, Mukwonago, West Milwaukee, Franklin, Vernon, Big Bend and
Milwaukee South Shore Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4285 8783 4284 8784 4285 8796 4284 8797
      4284 8836 4298 8829 4302 8790 4296 8785
      4288 8785
TIME...MOT...LOC 2318Z 271DEG 48KT 4289 8783 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CMILLER
918 
WWUS53 KMKX 112322
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
622 PM CDT Wed Aug 11 2021

WIC079-133-112332-
/O.EXP.KMKX.SV.W.0054.000000T0000Z-210811T2330Z/
Milwaukee WI-Waukesha WI-
622 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN MILWAUKEE AND
SOUTHEASTERN WAUKESHA COUNTIES WILL EXPIRE AT 630 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

LAT...LON 4285 8783 4284 8784 4285 8796 4284 8797
      4284 8836 4298 8829 4302 8790 4296 8785
      4288 8785
TIME...MOT...LOC 2322Z 271DEG 48KT 4289 8780 

$$

CMILLER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 7:05 PM CDTSpecial Weather StatementMKXJefferson25 min
Aug 10, 7:24 PM CDTSevere Thunderstorm WarningMKXSheboygan51 min
Aug 10, 7:43 PM CDTSevere Thunderstorm WarningMKXKenosha, Milwaukee, Ozaukee, Racine32 min
Aug 10, 8:07 PM CDTSpecial Marine WarningMKX53 min
Aug 10, 8:16 PM CDTSpecial Marine WarningMKX44 min
Aug 11, 6:44 AM CDTSmall Craft AdvisoryMKX15 hr
Aug 11, 9:58 AM CDTSpecial Weather StatementMKXKenosha, Milwaukee, Racine, Rock, Walworth77 min
Aug 11, 10:06 AM CDTSpecial Marine WarningMKX84 min
Aug 11, 2:46 PM CDTSevere Thunderstorm WarningMKXGreen Lake, Marquette59 min
Aug 11, 4:22 PM CDTSevere Thunderstorm WarningMKXIowa53 min
Aug 11, 5:05 PM CDTSpecial Weather StatementMKXIowa25 min
Aug 11, 5:10 PM CDTSevere Thunderstorm WarningMKXIowa50 min
Aug 11, 5:24 PM CDTSpecial Weather StatementMKXMilwaukee36 min
Aug 11, 5:56 PM CDTSpecial Marine WarningMKX94 min
Aug 11, 5:58 PM CDTSpecial Weather StatementMKXIowa47 min
Aug 11, 6:04 PM CDTTornado WarningMKXIowa41 min
Aug 11, 6:24 PM CDTSevere Thunderstorm WarningMKXKenosha, Racine, Walworth53 min
Aug 11, 6:34 PM CDTTornado WarningMKXDane15 min
Aug 11, 6:48 PM CDTSpecial Marine WarningMKX57 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.