Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 85, NWS Milwaukee, WI

September 20, 2021Columbia County, Sauk County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Sep 20, 2021, 7:46 PM CDT for Columbia County, Sauk County, Wisconsin. It was in force for 44 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, 7:46 PM CDT (00:46 UTC)
Expired: Sep 20, 2021, 8:30 PM CDT
In force: 44 min
Issued by: NWS Milwaukee, WI
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Columbia County, WI, Sauk County, WI

The radar

The La Crosse radar (KARX), 103 km from the middle of the area, began a volume at 00:48 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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 0.8 hours before the alert went out and 181 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: 429 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 735 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 194 m²/s²
0-3 km storm-relative helicity: 212 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.0

Open this sounding in Storm Lab

The text

As transmitted.

550 
WUUS53 KMKX 210046
SVRMKX
WIC021-111-210130-
/O.NEW.KMKX.SV.W.0085.210921T0046Z-210921T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
746 PM CDT Mon Sep 20 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Northwestern Columbia County in south central Wisconsin...
  Northern Sauk County in south central Wisconsin...

* Until 830 PM CDT.

* At 745 PM CDT, severe thunderstorms were located along a line
  extending from Wonewoc to 6 miles east of Richland Center, moving
  east at 45 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Baraboo and West Baraboo around 820 PM CDT.

Other locations impacted by these severe thunderstorms include
Ironton, Lime Ridge, North Freedom, Loganville, La Valle, Rock
Springs and Hill Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4364 8960 4348 8955 4338 9019 4355 9019
      4356 9031 4364 9031
TIME...MOT...LOC 0045Z 255DEG 39KT 4366 9022 4336 9026 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

GEHRING

3 follow-up statements

559 
WWUS53 KMKX 210056
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
756 PM CDT Mon Sep 20 2021

WIC021-111-210130-
/O.CON.KMKX.SV.W.0085.000000T0000Z-210921T0130Z/
Columbia WI-Sauk WI-
756 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM CDT
FOR NORTHWESTERN COLUMBIA AND NORTHERN SAUK COUNTIES...

At 756 PM CDT, severe thunderstorms were located along a line
extending from 6 miles east of Wonewoc to 12 miles east of Richland
Center, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Baraboo and West Baraboo around 825 PM CDT.

Other locations impacted by these severe thunderstorms include
Ironton, Lime Ridge, North Freedom, Loganville, La Valle, Rock
Springs and Hill Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4364 8960 4348 8955 4338 9019 4355 9019
      4356 9031 4364 9031
TIME...MOT...LOC 0056Z 253DEG 35KT 4368 9010 4338 9014 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

WOOD

084 
WWUS53 KMKX 210107
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
807 PM CDT Mon Sep 20 2021

WIC021-111-210130-
/O.CON.KMKX.SV.W.0085.000000T0000Z-210921T0130Z/
Columbia WI-Sauk WI-
807 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM CDT
FOR NORTHWESTERN COLUMBIA AND NORTHERN SAUK COUNTIES...

At 806 PM CDT, severe thunderstorms were located along a line
extending from 7 miles west of Wisconsin Dells to 9 miles south of
Reedsburg, moving east at 50 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Wisconsin Dells around 815 PM CDT.
  Baraboo, Lake Delton and West Baraboo around 820 PM CDT.

Other locations impacted by these severe thunderstorms include
Ironton, Lime Ridge, North Freedom, Loganville, La Valle, Rock
Springs and Hill Point.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4364 8960 4348 8955 4338 9019 4355 9019
      4356 9031 4364 9031
TIME...MOT...LOC 0106Z 266DEG 42KT 4365 8992 4340 9001 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

GEHRING

561 
WWUS53 KMKX 210126
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
826 PM CDT Mon Sep 20 2021

WIC021-111-210136-
/O.EXP.KMKX.SV.W.0085.000000T0000Z-210921T0130Z/
Columbia WI-Sauk WI-
826 PM CDT Mon Sep 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN COLUMBIA AND
NORTHERN SAUK COUNTIES WILL EXPIRE AT 830 PM CDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

LAT...LON 4364 8960 4348 8955 4338 9019 4355 9019
      4356 9031 4364 9031
TIME...MOT...LOC 0126Z 255DEG 39KT 4370 8965 4345 8974 

$$

GEHRING

The 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, 7:59 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, 9:22 PM CDT	Severe Thunderstorm Warning	MKX	Dane, Green, Iowa, Lafayette	38 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, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.