Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 77, NWS Milwaukee, WI

September 12, 2021Milwaukee County, Ozaukee County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Sep 12, 2021, 3:59 PM CDT for Milwaukee County, Ozaukee County, Wisconsin. It was in force for 33 min. 2 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, 3:59 PM CDT (20:59 UTC)
Expired
Sep 12, 2021, 4:32 PM CDT
In force
33 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Milwaukee County, WI, Ozaukee County, WI

The radar

The Milwaukee radar (KMKX), 58 km from the middle of the area, began a volume at 21:01 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, 4:19 PM CDTHAIL 0.7Mequon, WICORRECTS PREVIOUS HAIL REPORT FROM MEQUON. TIME ESTIMATED FROM RADAR.
Sep 12, 4:28 PM CDTHAIL 0.751 W Bayside, 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, 9.0 hours before the alert went out and 140 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.

294 
WUUS53 KMKX 122059
SVRMKX
WIC079-089-122145-
/O.NEW.KMKX.SV.W.0077.210912T2059Z-210912T2145Z/

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

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Southwestern Ozaukee County in southeastern Wisconsin...
  Northern Milwaukee County in southeastern Wisconsin...

* Until 445 PM CDT.

* At 358 PM CDT, a severe thunderstorm was located near Germantown,
  moving east at 55 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Northern Milwaukee, Mequon, Whitefish Bay, Brown Deer, Grafton,
  Cedarburg, Port Washington, Fox Point, Saukville, Bayside,
  Thiensville, Glendale, River Hills and Shorewood.

People attending The Packer Viewing Party in Shorewood should seek
safe shelter immediately!

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 4312 8807 4337 8806 4339 8786 4337 8788
      4330 8789 4328 8790 4324 8791 4318 8788
      4312 8790 4310 8787 4308 8787
TIME...MOT...LOC 2058Z 266DEG 46KT 4324 8823 

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

$$

DDV
2 follow-up statements
405 
WWUS53 KMKX 122125
SVSMKX

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

WIC079-089-122145-
/O.CON.KMKX.SV.W.0077.000000T0000Z-210912T2145Z/
Ozaukee WI-Milwaukee WI-
425 PM CDT Sun Sep 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM CDT
FOR SOUTHWESTERN OZAUKEE AND NORTHERN MILWAUKEE COUNTIES...

At 425 PM CDT, a severe thunderstorm was located 9 miles northeast of
Bayside, moving east at 55 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Northern Milwaukee, Mequon, Whitefish Bay, Brown Deer, Grafton,
Cedarburg, Fox Point, Bayside, Thiensville, Glendale, River Hills and
Shorewood.

People attending The Packer Viewing Party in Shorewood should seek
safe shelter immediately!

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 4312 8807 4317 8801 4332 8801 4333 8789
      4330 8789 4328 8790 4324 8791 4318 8788
      4312 8790 4310 8787 4308 8787
TIME...MOT...LOC 2125Z 266DEG 46KT 4326 8775 

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

$$

DDV
533 
WWUS53 KMKX 122132
SVSMKX

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

WIC079-089-122141-
/O.CAN.KMKX.SV.W.0077.000000T0000Z-210912T2145Z/
Ozaukee WI-Milwaukee WI-
432 PM CDT Sun Sep 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN OZAUKEE AND
NORTHERN MILWAUKEE COUNTIES IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

LAT...LON 4312 8807 4317 8801 4332 8801 4333 8789
      4330 8789 4328 8790 4324 8791 4318 8788
      4312 8790 4310 8787 4308 8787
TIME...MOT...LOC 2129Z 266DEG 46KT 4327 8764 

$$

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, 3:42 PM CDTSevere Thunderstorm WarningMKXDodge, Washington, Waukesha33 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.