Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 87, NWS Milwaukee, WI
NWS Milwaukee, WI issued this severe thunderstorm warning at Sep 20, 2021, 9:22 PM CDT for 4 counties in Wisconsin. It was in force for 38 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
- Sep 20, 2021, 9:22 PM CDT (02:22 UTC)
- Expired
- Sep 20, 2021, 10:00 PM CDT
- In force
- 38 min
- Issued by
- NWS Milwaukee, WI
- Area
- Storm-based polygon
- Tornado
- Possible
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Dane County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI
The radar
The Milwaukee radar (KMKX), 118 km from the middle of the area, began a volume at 02:25 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, 2.4 hours before the alert went out and 133 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
- 1090 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 1240 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 139 m²/s²
- 0-3 km storm-relative helicity
- 217 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 3.7
The text
As transmitted.
678 WUUS53 KMKX 210222 SVRMKX WIC025-045-049-065-210300- /O.NEW.KMKX.SV.W.0087.210921T0222Z-210921T0300Z/ BULLETIN - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Warning National Weather Service Milwaukee/Sullivan WI 922 PM CDT Mon Sep 20 2021 The National Weather Service in Milwaukee/Sullivan has issued a * Severe Thunderstorm Warning for... Northeastern Lafayette County in south central Wisconsin... Northwestern Green County in south central Wisconsin... Southeastern Iowa County in south central Wisconsin... Southwestern Dane County in south central Wisconsin... * Until 1000 PM CDT. * At 921 PM CDT, a severe thunderstorm was located over Darlington, moving northeast at 40 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. * Locations impacted include... Mount Horeb, Darlington, New Glarus, Argyle, Blanchardville, Waldwick, Fayette, Lamont, Hollandale, Yellowstone Lake St Park and Calamine. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. && LAT...LON 4260 9014 4275 9027 4302 8974 4277 8954 TIME...MOT...LOC 0221Z 240DEG 36KT 4272 9012 TORNADO...POSSIBLE HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ STUMPF
3 follow-up statements
572 WWUS53 KMKX 210235 SVSMKX Severe Weather Statement National Weather Service Milwaukee/Sullivan WI 935 PM CDT Mon Sep 20 2021 WIC025-045-049-065-210300- /O.CON.KMKX.SV.W.0087.000000T0000Z-210921T0300Z/ Lafayette WI-Green WI-Iowa WI-Dane WI- 935 PM CDT Mon Sep 20 2021 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT FOR NORTHEASTERN LAFAYETTE...NORTHWESTERN GREEN...SOUTHEASTERN IOWA AND SOUTHWESTERN DANE COUNTIES... At 935 PM CDT, a severe thunderstorm was located near Blanchardville, or 11 miles northeast of Darlington, moving northeast at 40 mph. HAZARD...60 mph wind gusts. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... Mount Horeb, New Glarus, Argyle, Blanchardville, Waldwick, Fayette, Lamont, Hollandale and Yellowstone Lake St Park. PRECAUTIONARY/PREPAREDNESS ACTIONS... For your protection move to an interior room on the lowest floor of a building. && LAT...LON 4265 8996 4282 9012 4302 8974 4277 8954 TIME...MOT...LOC 0235Z 240DEG 36KT 4279 8995 TORNADO...POSSIBLE HAIL THREAT...RADAR INDICATED MAX HAIL SIZE...<.75 IN WIND THREAT...RADAR INDICATED MAX WIND GUST...60 MPH $$ STUMPF
959
WWUS53 KMKX 210250
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
950 PM CDT Mon Sep 20 2021
WIC065-210259-
/O.CAN.KMKX.SV.W.0087.000000T0000Z-210921T0300Z/
Lafayette WI-
950 PM CDT Mon Sep 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LAFAYETTE COUNTY
IS CANCELLED...
The severe thunderstorm which prompted the warning has moved out of
the warned area. Therefore, the warning has been cancelled.
LAT...LON 4271 8974 4292 8993 4302 8974 4277 8954
TIME...MOT...LOC 0249Z 240DEG 36KT 4286 8978
$$
WIC025-045-049-210300-
/O.CON.KMKX.SV.W.0087.000000T0000Z-210921T0300Z/
Green WI-Iowa WI-Dane WI-
950 PM CDT Mon Sep 20 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT
FOR NORTHWESTERN GREEN...EASTERN IOWA AND SOUTHWESTERN DANE
COUNTIES...
At 949 PM CDT, a severe thunderstorm was located near Blanchardville,
or 10 miles south of Mount Horeb, moving northeast at 40 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Mount Horeb, New Glarus and Monticello.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4271 8974 4292 8993 4302 8974 4277 8954
TIME...MOT...LOC 0249Z 240DEG 36KT 4286 8978
TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
STUMPF284
WWUS53 KMKX 210256
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
956 PM CDT Mon Sep 20 2021
WIC025-045-049-210306-
/O.EXP.KMKX.SV.W.0087.000000T0000Z-210921T0300Z/
Green WI-Iowa WI-Dane WI-
956 PM CDT Mon Sep 20 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN GREEN...EASTERN
IOWA AND SOUTHWESTERN DANE COUNTIES WILL EXPIRE AT 1000 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 gusty
winds are still possible with this thunderstorm.
LAT...LON 4271 8974 4292 8993 4302 8974 4277 8954
TIME...MOT...LOC 0256Z 240DEG 36KT 4289 8972
$$
STUMPFThe office that day
Everything else NWS Milwaukee, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 7:22 PM CDT | Severe Thunderstorm Warning | MKX | Iowa, Sauk | 38 min |
| Sep 20, 7:46 PM CDT | Severe Thunderstorm Warning | MKX | Columbia, Sauk | 44 min |
| Sep 20, 7:59 PM CDT | Special Weather Statement | MKX | Iowa | 31 min |
| Sep 20, 8:23 PM CDT | Special Weather Statement | MKX | Marquette | 37 min |
| Sep 20, 8:37 PM CDT | Special Weather Statement | MKX | Columbia, Sauk | 38 min |
| Sep 20, 9:14 PM CDT | Special Weather Statement | MKX | Lafayette | 46 min |
| Sep 20, 9:21 PM CDT | Severe Thunderstorm Warning | MKX | Columbia, Dodge | 24 min |
| Sep 20, 9:24 PM CDT | Tornado Warning | MKX | Dane, Green, Iowa, Lafayette | 24 min |
| Sep 20, 9:44 PM CDT | Special Weather Statement | MKX | Green Lake | 46 min |
| Sep 20, 10:04 PM CDT | Special Weather Statement | MKX | Green | 41 min |
| Sep 20, 10:27 PM CDT | Special Weather Statement | MKX | Jefferson | 48 min |
| Sep 20, 10:41 PM CDT | Severe Thunderstorm Warning | MKX | Dane, Jefferson | 20 min |
| Sep 21, 3:04 AM CDT | Gale Watch | MKX | 11 hr | |
| Sep 21, 1:48 PM CDT | Gale Warning | MKX | 50 hr | |
| Sep 21, 1:48 PM CDT | Small Craft Advisory | MKX | 17 hr | |
| Sep 21, 1:51 PM CDT | Beach Hazards Statement | MKX | Kenosha, Milwaukee, Ozaukee, Racine, Sheboygan | 58 hr |
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.