Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 28, NWS Milwaukee, WI

August 6, 2021Rock County, Walworth County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 6, 2021, 8:14 PM CDT for Rock County, Walworth County, Wisconsin. It was in force for 31 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, 8:14 PM CDT (01:14 UTC)
Expired: Aug 6, 2021, 8:45 PM CDT
In force: 31 min
Issued by: NWS Milwaukee, WI
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Rock County, WI, Walworth County, WI

The radar

The Milwaukee radar (KMKX), 30 km from the middle of the area, began a volume at 01:14 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, 8:28 PM CDT	FUNNEL CLOUD	5 W Whitewater, WI	SPOTTER REPORTS FUNNEL CLOUD EXTENDING ABOUT HALF WAY DOWN.

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

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 1.2 hours before the alert went out and 190 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: 2016 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 1080 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 27 m²/s²
0-3 km storm-relative helicity: 113 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

380 
WUUS53 KMKX 070114
SVRMKX
WIC105-127-070145-
/O.NEW.KMKX.SV.W.0028.210807T0114Z-210807T0145Z/

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

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Northwestern Walworth County in southeastern Wisconsin...
  Northeastern Rock County in south central Wisconsin...

* Until 845 PM CDT.

* At 813 PM CDT, a severe thunderstorm was located near Whitewater,
  moving east at 10 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Whitewater, Richmond and Lima Center. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4274 8888 4284 8886 4284 8866 4268 8870
TIME...MOT...LOC 0113Z 278DEG 7KT 4282 8880 

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

$$

CMILLER

2 follow-up statements

726 
WWUS53 KMKX 070119
SVSMKX

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

WIC105-127-070145-
/O.CON.KMKX.SV.W.0028.000000T0000Z-210807T0145Z/
Walworth WI-Rock WI-
819 PM CDT Fri Aug 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR NORTHWESTERN WALWORTH AND NORTHEASTERN ROCK COUNTIES...

At 818 PM CDT, a severe thunderstorm was located over Whitewater,
moving east at 10 mph.

HAZARD...Quarter size hail.

SOURCE...Trained weather spotters. At 810 PM, quarter size hail was 
         reported west of Whitewater on County Road N.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Whitewater, Richmond and Lima Center. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4274 8888 4284 8886 4284 8866 4268 8870
TIME...MOT...LOC 0118Z 278DEG 7KT 4282 8879 

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

$$

CMILLER

744 
WWUS53 KMKX 070144
SVSMKX

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

WIC105-127-070153-
/O.EXP.KMKX.SV.W.0028.000000T0000Z-210807T0145Z/
Walworth WI-Rock WI-
844 PM CDT Fri Aug 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WALWORTH AND
NORTHEASTERN ROCK COUNTIES WILL EXPIRE AT 845 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.  However heavy 
rain is still possible with this thunderstorm. An areal flood 
advisory remains in effect for northeastern Rock and northwestern 
Walworth county.

LAT...LON 4274 8888 4284 8886 4284 8866 4268 8870
TIME...MOT...LOC 0143Z 278DEG 7KT 4281 8873 

$$

CMILLER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 7:34 PM CDT	Areal Flood Advisory	MKX	Milwaukee, Waukesha	119 min
Aug 6, 7:38 PM CDT	Severe Thunderstorm Warning	MKX	Jefferson	37 min
Aug 6, 7:55 PM CDT	Special Marine Warning	MKX		50 min
Aug 6, 7:57 PM CDT	Special Weather Statement	MKX	Kenosha, Racine, Walworth	63 min
Aug 6, 8:00 PM CDT	Areal Flood Advisory	MKX	Jefferson, Rock, Walworth	2 hr
Aug 6, 8:51 PM CDT	Special Weather Statement	MKX	Rock, Walworth	54 min
Aug 6, 9:45 PM CDT	Severe Thunderstorm Warning	MKX	Dane	30 min
Aug 6, 10:15 PM CDT	Special Weather Statement	MKX	Dane	30 min
Aug 7, 10:06 AM CDT	Special Weather Statement	MKX	Columbia, Marquette	54 min
Aug 7, 11:01 AM CDT	Special Weather Statement	MKX	Columbia, Green Lake	59 min
Aug 7, 11:47 AM CDT	Special Weather Statement	MKX	Dodge, Jefferson	58 min
Aug 7, 12:32 PM CDT	Severe Thunderstorm Warning	MKX	Jefferson	43 min
Aug 7, 12:54 PM CDT	Severe Thunderstorm Warning	MKX	Jefferson, Waukesha	45 min
Aug 7, 1:48 PM CDT	Severe Thunderstorm Warning	MKX	Sauk	42 min
Aug 7, 3:53 PM CDT	Severe Thunderstorm Warning Considerable damage threat	MKX	Sauk	52 min
Aug 7, 4:33 PM CDT	Severe Thunderstorm Warning Considerable damage threat	MKX	Columbia, Dane, Iowa, Sauk	57 min
Aug 7, 4:38 PM CDT	Tornado Warning Tornado observed	MKX	Iowa	67 min
Aug 7, 5:17 PM CDT	Severe Thunderstorm Warning	MKX	Columbia, Green Lake, Marquette, Sauk	58 min
Aug 7, 5:26 PM CDT	Tornado Warning	MKX	Columbia	39 min
Aug 7, 5:31 PM CDT	Severe Thunderstorm Warning	MKX	Columbia, Dane	59 min
Aug 7, 5:33 PM CDT	Tornado Warning	MKX	Iowa	57 min
Aug 7, 6:03 PM CDT	Special Weather Statement	MKX	Dodge, Fond du Lac, Green Lake	42 min
Aug 7, 6:09 PM CDT	Severe Thunderstorm Warning	MKX	Dane	66 min
Aug 7, 6:25 PM CDT	Severe Thunderstorm Warning	MKX	Dane	50 min
Aug 7, 6:40 PM CDT	Special Weather Statement	MKX	Jefferson	50 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.