Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 4, NWS Milwaukee, WI
NWS Milwaukee, WI issued this severe thunderstorm warning at Jun 20, 2021, 8:40 PM CDT for Rock County, Wisconsin. It was in force for 22 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
- Jun 20, 2021, 8:40 PM CDT (01:40 UTC)
- Expired
- Jun 20, 2021, 9:02 PM CDT
- In force
- 22 min
- Issued by
- NWS Milwaukee, WI
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 50.0 mph
County Rock County, WI
The radar
The Milwaukee radar (KMKX), 65 km from the middle of the area, began a volume at 01:39 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
Davenport, (KDVN), launched 00:00Z, 1.7 hours before the alert went out and 154 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.
- Mixed-layer CAPE
- 1058 J/kg
- Mixed-layer CIN
- -19 J/kg
- Mixed-layer LCL
- 1009 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 174 m²/s²
- 0-3 km storm-relative helicity
- 230 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 7.8
The text
As transmitted.
392
WUUS53 KMKX 210140
SVRMKX
WIC105-210245-
/O.NEW.KMKX.SV.W.0004.210621T0140Z-210621T0245Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
840 PM CDT Sun Jun 20 2021
The National Weather Service in Milwaukee/Sullivan has issued a
* Severe Thunderstorm Warning for...
Southeastern Rock County in south central Wisconsin...
* Until 945 PM CDT.
* At 839 PM CDT, a severe thunderstorm was located over Durand, or 13
miles south of Brodhead, moving northeast at 45 mph.
HAZARD...Quarter size hail.
SOURCE...Radar indicated.
IMPACT...Damage to vehicles is expected.
* Locations impacted include...
Janesville, Beloit, South Beloit, Clinton, Newark, Tiffany,
Hanover, Avalon, Afton, Shopiere, Avon, Emerald Grove, Johnstown
Center, Foxhollow and Lima Center.
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.
Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.
&&
LAT...LON 4250 8936 4250 8937 4255 8936 4263 8924
4283 8878 4250 8878 4249 8881
TIME...MOT...LOC 0139Z 236DEG 39KT 4242 8936
HAIL...1.00IN
WIND...<50MPH
$$
COLLAR2 follow-up statements
448
WWUS53 KMKX 210155
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
855 PM CDT Sun Jun 20 2021
WIC105-210245-
/O.CON.KMKX.SV.W.0004.000000T0000Z-210621T0245Z/
Rock WI-
855 PM CDT Sun Jun 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT
FOR SOUTHERN ROCK COUNTY...
At 855 PM CDT, a severe thunderstorm was located near Rockton, moving
northeast at 50 mph.
HAZARD...Quarter size hail.
SOURCE...Radar indicated.
IMPACT...Damage to vehicles is expected.
Locations impacted include...
Janesville, Beloit, Clinton, Newark, Tiffany, Johnstown Center,
Foxhollow, Avalon, Afton, Shopiere, Lima Center and Emerald Grove.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.
&&
LAT...LON 4250 8928 4251 8928 4256 8927 4266 8909
4283 8878 4250 8878 4249 8881
TIME...MOT...LOC 0155Z 229DEG 45KT 4251 8914
HAIL...1.00IN
WIND...<50MPH
$$
COLLAR668
WWUS53 KMKX 210202
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
902 PM CDT Sun Jun 20 2021
WIC105-210211-
/O.CAN.KMKX.SV.W.0004.000000T0000Z-210621T0245Z/
Rock WI-
902 PM CDT Sun Jun 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN ROCK COUNTY IS
CANCELLED...
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 has been cancelled.
LAT...LON 4250 8928 4251 8928 4256 8927 4266 8909
4283 8878 4250 8878 4249 8881
TIME...MOT...LOC 0200Z 236DEG 39KT 4255 8906
$$
COLLARNearby
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.