Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 60, NWS Milwaukee, WI

August 27, 2021Dane County, Iowa County, Sauk County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 27, 2021, 8:57 AM CDT for Dane County, Iowa County, Sauk County, Wisconsin. It was in force for 48 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
Aug 27, 2021, 8:57 AM CDT (13:57 UTC)
Expired
Aug 27, 2021, 9:45 AM CDT
In force
48 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Dane County, WI, Iowa County, WI, Sauk County, WI

The radar

The Milwaukee radar (KMKX), 118 km from the middle of the area, began a volume at 13:59 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 12:00Z, 2.0 hours before the alert went out and 183 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, Davenport, at 12:00Z on 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 358 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, Davenport, at 12:00Z on 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 square meters per square second.1939Sfc1 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
358 J/kg
Mixed-layer CIN
-231 J/kg
Mixed-layer LCL
1213 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

606 
WUUS53 KMKX 271357
SVRMKX
WIC025-049-111-271445-
/O.NEW.KMKX.SV.W.0060.210827T1357Z-210827T1445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Milwaukee/Sullivan WI
857 AM CDT Fri Aug 27 2021

The National Weather Service in Milwaukee/Sullivan has issued a

* Severe Thunderstorm Warning for...
  Northeastern Iowa County in south central Wisconsin...
  Northwestern Dane County in south central Wisconsin...
  Southern Sauk County in south central Wisconsin...

* Until 945 AM CDT.

* At 856 AM CDT, severe thunderstorms were located along a line
  extending from 6 miles northwest of Spring Green to near
  Dodgeville, moving northeast at 35 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Baraboo, Dodgeville, Prairie Du Sac, Sauk City, Mazomanie, Spring
  Green, Black Earth, Barneveld, Blue Mounds, Arena, Plain,
  Bluffview, Ridgeway, Clyde, Governor Dodge St Park, Blue Mound St
  Park and Devils Lake St Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4317 9020 4325 9019 4349 8972 4333 8971
      4330 8973 4329 8971 4305 8969 4295 9021
      4320 9027
TIME...MOT...LOC 1356Z 246DEG 30KT 4325 9014 4304 9012 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HANSEN
2 follow-up statements
068 
WWUS53 KMKX 271415
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
915 AM CDT Fri Aug 27 2021

WIC025-049-111-271445-
/O.CON.KMKX.SV.W.0060.000000T0000Z-210827T1445Z/
Iowa WI-Dane WI-Sauk WI-
915 AM CDT Fri Aug 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 AM CDT
FOR NORTHEASTERN IOWA...NORTHWESTERN DANE AND SOUTHEASTERN SAUK
COUNTIES...

At 915 AM CDT, severe thunderstorms were located along a line
extending from 10 miles west of Prairie Du Sac to 8 miles southwest
of Mazomanie, moving east at 35 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Prairie Du Sac, Sauk City, Mazomanie, Spring Green, Black Earth,
Barneveld, Blue Mounds, Arena, Plain, Bluffview, Ridgeway, Blue Mound
St Park and Devils Lake St Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4324 9011 4344 8972 4333 8971 4330 8973
      4329 8971 4305 8969 4298 9005
TIME...MOT...LOC 1415Z 250DEG 32KT 4330 8994 4309 8992 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

HANSEN
737 
WWUS53 KMKX 271437
SVSMKX

Severe Weather Statement
National Weather Service Milwaukee/Sullivan WI
937 AM CDT Fri Aug 27 2021

WIC025-049-111-271446-
/O.EXP.KMKX.SV.W.0060.000000T0000Z-210827T1445Z/
Iowa WI-Dane WI-Sauk WI-
937 AM CDT Fri Aug 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN IOWA...
NORTHWESTERN DANE AND SOUTHEASTERN SAUK COUNTIES WILL EXPIRE AT 945
AM CDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 4324 9011 4344 8972 4333 8971 4330 8973
      4329 8971 4305 8969 4298 9005
TIME...MOT...LOC 1436Z 246DEG 30KT 4337 8973 4316 8971 

$$

HANSEN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 9:02 AM CDTSpecial Weather StatementMKXDodge43 min
Aug 27, 9:27 AM CDTSevere Thunderstorm WarningMKXColumbia, Dane, Sauk48 min
Aug 27, 10:05 AM CDTAreal Flood AdvisoryMKXColumbia, Sauk75 min
Aug 27, 10:08 AM CDTSpecial Weather StatementMKXColumbia52 min
Aug 27, 10:47 AM CDTSpecial Weather StatementMKXDodge, Fond du Lac43 min
Aug 27, 11:19 AM CDTSpecial Weather StatementMKXFond du Lac41 min
Aug 27, 11:59 AM CDTSpecial Weather StatementMKXSheboygan31 min
Aug 27, 2:46 PM CDTSpecial Weather StatementMKXFond du Lac44 min
Aug 27, 3:24 PM CDTSpecial Weather StatementMKXSheboygan51 min
Aug 27, 4:01 PM CDTSpecial Weather StatementMKXDodge59 min
Aug 27, 4:07 PM CDTSevere Thunderstorm WarningMKXSheboygan26 min
Aug 27, 4:09 PM CDTSpecial Marine WarningMKX66 min
Aug 27, 4:35 PM CDTSpecial Weather StatementMKXWashington25 min
Aug 27, 4:44 PM CDTSevere Thunderstorm WarningMKXDodge, Washington46 min
Aug 27, 5:28 PM CDTSpecial Weather StatementMKXWashington47 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.