Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 45, NWS Milwaukee, WI
NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 10, 2021, 5:42 PM CDT for 4 counties in Wisconsin. It was in force for 78 min. 5 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
- Aug 10, 2021, 5:42 PM CDT (22:42 UTC)
- Expired
- Aug 10, 2021, 7:00 PM CDT
- In force
- 78 min
- Issued by
- NWS Milwaukee, WI
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Dane County, WI, Dodge County, WI, Jefferson County, WI, Rock County, WI
The radar
The Milwaukee radar (KMKX), 39 km from the middle of the area, began a volume at 22:46 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 10, 6:15 PM CDT | TSTM WND DMG | 2 Sw Janesville, WI | TREE SPLIT...LARGE LIMB. |
| Aug 10, 6:20 PM CDT | TSTM WND DMG | 5 Nne Waterloo, WI | POWER LINES DOWN IN TOWN OF PORTLAND. |
| Aug 10, 6:30 PM CDT | TSTM WND DMG | 1 S Beaver Dam, WI | POWER LINES DOWN. |
| Aug 10, 6:35 PM CDT | TSTM WND DMG | 1 Ene Watertown, WI | MEDIUM SIZE TREE UPROOTED. |
| Aug 10, 6:35 PM CDT | TSTM WND GST 44 | 1 S Watertown, WI | RYV - WATERTOWN. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 10, 3:47 PM CDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Green Bay/Straub, WI (KGRB), launched 12:00Z, 10.7 hours before the alert went out and 187 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
- 32 J/kg
- Mixed-layer CIN
- -550 J/kg
- Mixed-layer LCL
- 828 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 42 m²/s²
- 0-3 km storm-relative helicity
- 117 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
001
WUUS53 KMKX 102242
SVRMKX
WIC025-027-055-105-110000-
/O.NEW.KMKX.SV.W.0045.210810T2242Z-210811T0000Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
542 PM CDT Tue Aug 10 2021
The National Weather Service in Milwaukee/Sullivan has issued a
* Severe Thunderstorm Warning for...
Rock County in south central Wisconsin...
Southeastern Dane County in south central Wisconsin...
Jefferson County in southeastern Wisconsin...
Dodge County in southeastern Wisconsin...
* Until 700 PM CDT.
* At 542 PM CDT, severe thunderstorms were located along a line
extending from near Portage to near Fitchburg to 6 miles southwest
of Brodhead, moving northeast at 35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Janesville, Beloit, Watertown, Beaver Dam, Whitewater, Stoughton,
Fort Atkinson, Waupun, Jefferson, South Beloit, Lake Mills, Milton,
Edgerton, Evansville, Marshall, Horicon, Waterloo, Juneau, Johnson
Creek and Deerfield.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4250 8936 4285 8937 4285 8929 4324 8901
4363 8901 4363 8861 4284 8870 4283 8878
4249 8878
TIME...MOT...LOC 2242Z 245DEG 31KT 4357 8940 4301 8945 4255 8947
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
KAVINSKY4 follow-up statements
095
WWUS53 KMKX 102314
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
614 PM CDT Tue Aug 10 2021
WIC025-027-055-105-110000-
/O.CON.KMKX.SV.W.0045.000000T0000Z-210811T0000Z/
Rock WI-Dane WI-Jefferson WI-Dodge WI-
614 PM CDT Tue Aug 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR ROCK...SOUTHEASTERN DANE...JEFFERSON AND DODGE COUNTIES...
At 614 PM CDT, severe thunderstorms were located along a line
extending from 6 miles southwest of Markesan to near Cottage Grove to
near Clinton, moving east at 35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Janesville, Beloit, Watertown, Beaver Dam, Whitewater, Stoughton,
Fort Atkinson, Waupun, Jefferson, South Beloit, Lake Mills, Milton,
Edgerton, Evansville, Marshall, Horicon, Waterloo, Juneau, Johnson
Creek and Deerfield.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4250 8936 4285 8937 4285 8929 4324 8901
4363 8901 4363 8861 4284 8870 4283 8878
4249 8878
TIME...MOT...LOC 2314Z 269DEG 31KT 4367 8910 4311 8915 4251 8894
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
KAVINSKY446
WWUS53 KMKX 102328
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
628 PM CDT Tue Aug 10 2021
WIC025-027-055-105-110000-
/O.CON.KMKX.SV.W.0045.000000T0000Z-210811T0000Z/
Rock WI-Dane WI-Jefferson WI-Dodge WI-
628 PM CDT Tue Aug 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR ROCK...SOUTHEASTERN DANE...JEFFERSON AND DODGE COUNTIES...
At 627 PM CDT, severe thunderstorms were located along a line
extending from near Waupun to near Jefferson to near Clinton, moving
east at 45 mph.
HAZARD...60 mph wind gusts.
SOURCE...Tree damage was reported in Rock County around Janesville.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Janesville, Beloit, Watertown, Beaver Dam, Whitewater, Stoughton,
Fort Atkinson, Waupun, Jefferson, South Beloit, Lake Mills, Milton,
Edgerton, Evansville, Marshall, Horicon, Waterloo, Juneau, Johnson
Creek and Deerfield.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4250 8936 4285 8937 4285 8929 4324 8901
4363 8901 4363 8861 4284 8870 4283 8878
4249 8878
TIME...MOT...LOC 2327Z 270DEG 40KT 4360 8884 4300 8885 4254 8884
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
KAVINSKY139
WWUS53 KMKX 102354
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
654 PM CDT Tue Aug 10 2021
WIC025-027-055-105-110000-
/O.CON.KMKX.SV.W.0045.000000T0000Z-210811T0000Z/
Rock WI-Dane WI-Jefferson WI-Dodge WI-
654 PM CDT Tue Aug 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM CDT
FOR ROCK...SOUTHEASTERN DANE...JEFFERSON AND DODGE COUNTIES...
At 653 PM CDT, Strong thunderstorms located along a line extending
from near Oakfield to near Oconomowoc to Delavan, moving east at 35
mph.
HAZARD...60 mph wind gusts.
SOURCE...A 68 mph wind gust was reported in Eagle in Waukesha
County.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Janesville, Beloit, Watertown, Beaver Dam, Whitewater, Stoughton,
Fort Atkinson, Waupun, Jefferson, South Beloit, Lake Mills, Milton,
Edgerton, Evansville, Marshall, Horicon, Waterloo, Juneau, Johnson
Creek and Deerfield.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4250 8936 4285 8937 4285 8929 4324 8901
4363 8901 4363 8861 4284 8870 4283 8878
4249 8878
TIME...MOT...LOC 2353Z 270DEG 31KT 4368 8859 4308 8861 4262 8860
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...OBSERVED
MAX WIND GUST...60 MPH
$$
KAVINSKY122
WWUS53 KMKX 110000
SVSMKX
Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
700 PM CDT Tue Aug 10 2021
WIC025-027-055-105-110009-
/O.EXP.KMKX.SV.W.0045.000000T0000Z-210811T0000Z/
Rock WI-Dane WI-Jefferson WI-Dodge WI-
700 PM CDT Tue Aug 10 2021
...THE SEVERE THUNDERSTORM WARNING FOR ROCK...SOUTHEASTERN DANE...
JEFFERSON AND DODGE COUNTIES WILL EXPIRE AT 700 PM CDT...
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.
A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
south central and southeastern Wisconsin.
LAT...LON 4250 8936 4285 8937 4285 8929 4324 8901
4363 8901 4363 8861 4284 8870 4283 8878
4249 8878
TIME...MOT...LOC 2359Z 270DEG 31KT 4369 8857 4309 8859 4263 8858
$$
KAVINSKYThe office that day
Everything else NWS Milwaukee, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 7:13 PM CDT | Marine Dense Fog Advisory | MKX | 14 hr | |
| Aug 10, 2:16 PM CDT | Heat Advisory | MKX | Dane, Dodge, Green, Iowa, Jefferson, Kenosha and 8 more | 29 hr |
| Aug 10, 4:02 PM CDT | Severe Thunderstorm Warning | MKX | Dane, Iowa, Lafayette, Sauk | 73 min |
| Aug 10, 4:25 PM CDT | Severe Thunderstorm Warning | MKX | Iowa, Lafayette | 80 min |
| Aug 10, 5:08 PM CDT | Severe Thunderstorm Warning | MKX | Columbia, Dane, Green, Iowa, Sauk | 67 min |
| Aug 10, 5:36 PM CDT | Special Weather Statement | MKX | Rock | 39 min |
| Aug 10, 6:08 PM CDT | Severe Thunderstorm Warning | MKX | Dodge, Jefferson, Kenosha, Racine, Walworth, Washington and 1 more | 97 min |
| Aug 10, 6:12 PM CDT | Severe Thunderstorm Warning | MKX | Columbia, Dane | 20 min |
| Aug 10, 6:24 PM CDT | Special Marine Warning | MKX | 111 min | |
| Aug 10, 6:44 PM CDT | Special Weather Statement | MKX | Fond du Lac, Sheboygan | 76 min |
| Aug 10, 6:51 PM CDT | Severe Thunderstorm Warning | MKX | Kenosha, Milwaukee, Ozaukee, Racine | 54 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.