Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 86, NWS Milwaukee, WI

September 20, 2021Columbia County, Dodge County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Sep 20, 2021, 9:21 PM CDT for Columbia County, Dodge County, Wisconsin. It was in force for 24 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, 9:21 PM CDT (02:21 UTC)
Expired
Sep 20, 2021, 9:45 PM CDT
In force
24 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Columbia County, WI, Dodge County, WI

The radar

The Milwaukee radar (KMKX), 61 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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 2.4 hours before the alert went out and 141 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-pSkew-T log-p diagram, Green Bay/Straub, WI at 00:00Z on 2021-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 429 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 00:00Z on 2021-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 194 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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.

442 
WUUS53 KMKX 210221
SVRMKX
WIC021-027-210245-
/O.NEW.KMKX.SV.W.0086.210921T0221Z-210921T0245Z/

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

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Southeastern Columbia County in south central Wisconsin...
  Northwestern Dodge County in southeastern Wisconsin...

* Until 945 PM CDT.

* At 920 PM CDT, a severe thunderstorm was located 8 miles northeast
  of Deforest, or 9 miles north of Sun Prairie, moving northeast at
  50 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* This severe thunderstorm will be near...
  Fall River around 930 PM CDT.
  Columbus around 935 PM CDT.
  Beaver Dam around 945 PM CDT.

Other locations impacted by this severe thunderstorm include
Danville, Otsego, South Beaver Dam, Leipsig and Doylestown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4356 8884 4337 8875 4328 8901 4328 8932
      4335 8935
TIME...MOT...LOC 0220Z 240DEG 45KT 4332 8922 

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

$$

GEHRING
1 follow-up statement
888 
WWUS53 KMKX 210232
SVSMKX

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

WIC021-027-210245-
/O.CON.KMKX.SV.W.0086.000000T0000Z-210921T0245Z/
Columbia WI-Dodge WI-
932 PM CDT Mon Sep 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM CDT
FOR SOUTHEASTERN COLUMBIA AND NORTHWESTERN DODGE COUNTIES...

At 932 PM CDT, a severe thunderstorm was located over Fall River, or
near Columbus, moving northeast at 50 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

This severe storm will be near...
  Beaver Dam around 945 PM CDT.

Other locations impacted by this severe thunderstorm include
Danville, Otsego, South Beaver Dam, Leipsig and Doylestown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4356 8884 4337 8875 4328 8901 4328 8920
      4339 8924
TIME...MOT...LOC 0232Z 240DEG 45KT 4340 8904 

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

$$

GEHRING

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 7:22 PM CDTSevere Thunderstorm WarningMKXIowa, Sauk38 min
Sep 20, 7:46 PM CDTSevere Thunderstorm WarningMKXColumbia, Sauk44 min
Sep 20, 7:59 PM CDTSpecial Weather StatementMKXIowa31 min
Sep 20, 8:23 PM CDTSpecial Weather StatementMKXMarquette37 min
Sep 20, 8:37 PM CDTSpecial Weather StatementMKXColumbia, Sauk38 min
Sep 20, 9:14 PM CDTSpecial Weather StatementMKXLafayette46 min
Sep 20, 9:22 PM CDTSevere Thunderstorm WarningMKXDane, Green, Iowa, Lafayette38 min
Sep 20, 9:24 PM CDTTornado WarningMKXDane, Green, Iowa, Lafayette24 min
Sep 20, 9:44 PM CDTSpecial Weather StatementMKXGreen Lake46 min
Sep 20, 10:04 PM CDTSpecial Weather StatementMKXGreen41 min
Sep 20, 10:27 PM CDTSpecial Weather StatementMKXJefferson48 min
Sep 20, 10:41 PM CDTSevere Thunderstorm WarningMKXDane, Jefferson20 min
Sep 21, 3:04 AM CDTGale WatchMKX11 hr
Sep 21, 1:48 PM CDTGale WarningMKX50 hr
Sep 21, 1:48 PM CDTSmall Craft AdvisoryMKX17 hr
Sep 21, 1:51 PM CDTBeach Hazards StatementMKXKenosha, Milwaukee, Ozaukee, Racine, Sheboygan58 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.