Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 26, NWS Milwaukee, WI

August 6, 2021Jefferson County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 6, 2021, 6:22 PM CDT for Jefferson County, Wisconsin. It was in force for 38 min. 1 report 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 6, 2021, 6:22 PM CDT (23:22 UTC)
Expired: Aug 6, 2021, 7:00 PM CDT
In force: 38 min
Issued by: NWS Milwaukee, WI
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Jefferson County, WI

The radar

The Milwaukee radar (KMKX), 27 km from the middle of the area, began a volume at 23:22 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 6, 6:32 PM CDT	HAIL 1.5	1 Ese Johnson Creek, WI	1 TO 1.5 HAIL. PICTURE VIA SOCIAL MEDIA.

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, 11.4 hours before the alert went out and 170 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: 132 J/kg
Mixed-layer CIN: -114 J/kg
Mixed-layer LCL: 962 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 84 m²/s²
0-3 km storm-relative helicity: 98 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

473 
WUUS53 KMKX 062322
SVRMKX
WIC055-070000-
/O.NEW.KMKX.SV.W.0026.210806T2322Z-210807T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
622 PM CDT Fri Aug 6 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Central Jefferson County in southeastern Wisconsin...

* Until 700 PM CDT.

* At 622 PM CDT, a severe thunderstorm was located over Lake Mills,
  moving east at 15 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...
  Jefferson, Lake Mills, Johnson Creek and Milford. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4299 8892 4311 8894 4317 8878 4300 8872
TIME...MOT...LOC 2322Z 260DEG 13KT 4306 8886 

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

$$

HANSEN

1 follow-up statement

235 
WWUS53 KMKX 062353
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
653 PM CDT Fri Aug 6 2021

WIC055-070003-
/O.EXP.KMKX.SV.W.0026.000000T0000Z-210807T0000Z/
Jefferson WI-
653 PM CDT Fri Aug 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL JEFFERSON COUNTY WILL
EXPIRE AT 700 PM CDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 4299 8892 4311 8894 4317 8878 4300 8872
TIME...MOT...LOC 2353Z 270DEG 13KT 4308 8872 

$$

HANSEN

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 3:06 PM CDT	Special Weather Statement	MKX	Calumet	24 min
Aug 6, 3:44 PM CDT	Special Weather Statement	MKX	Sheboygan	31 min
Aug 6, 3:48 PM CDT	Special Marine Warning	MKX		42 min
Aug 6, 4:04 PM CDT	Severe Thunderstorm Warning	MKX	Fond du Lac, Sheboygan	41 min
Aug 6, 4:09 PM CDT	Severe Thunderstorm Warning	MKX	Dodge, Fond du Lac	39 min
Aug 6, 4:21 PM CDT	Severe Thunderstorm Warning	MKX	Sheboygan	24 min
Aug 6, 4:23 PM CDT	Special Marine Warning	MKX		52 min
Aug 6, 4:38 PM CDT	Severe Thunderstorm Warning	MKX	Sheboygan	52 min
Aug 6, 4:41 PM CDT	Special Marine Warning	MKX		64 min
Aug 6, 4:58 PM CDT	Severe Thunderstorm Warning	MKX	Dodge, Jefferson	32 min
Aug 6, 5:06 PM CDT	Severe Thunderstorm Warning	MKX	Ozaukee, Sheboygan	24 min
Aug 6, 5:08 PM CDT	Special Marine Warning	MKX		52 min
Aug 6, 5:23 PM CDT	Special Marine Warning	MKX		111 min
Aug 6, 5:26 PM CDT	Special Weather Statement	MKX	Dodge, Ozaukee, Washington, Waukesha	94 min
Aug 6, 6:53 PM CDT	Special Weather Statement	MKX	Jefferson, Milwaukee, Waukesha	82 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.