Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 78, NWS Milwaukee, WI

August 4, 2012Rock County, Walworth County, Wisconsin

NWS Milwaukee, WI issued this severe thunderstorm warning at Aug 4, 2012, 3:22 PM CDT for Rock County, Walworth County, 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
Aug 4, 2012, 3:22 PM CDT (20:22 UTC)
Expired
Aug 4, 2012, 4:00 PM CDT
In force
38 min
Issued by
NWS Milwaukee, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Rock County, WI, Walworth County, WI

The radar

The Milwaukee radar (KMKX), 53 km from the middle of the area, began a volume at 20:23 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 4, 1:46 PM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.4 hours before the alert went out and 169 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 2012-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1247 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 2012-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
1247 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1158 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

701 
WUUS53 KMKX 042022
SVRMKX
WIC105-127-042100-
/O.NEW.KMKX.SV.W.0078.120804T2022Z-120804T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
322 PM CDT SAT AUG 4 2012

THE NATIONAL WEATHER SERVICE IN SULLIVAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN ROCK COUNTY IN SOUTH CENTRAL WISCONSIN...
  SOUTHERN WALWORTH COUNTY IN SOUTHEAST WISCONSIN...

* UNTIL 400 PM CDT

* AT 319 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
  HAIL...AND DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THESE STORMS
  WERE LOCATED ALONG A LINE EXTENDING FROM ROCKTON TO 9 MILES SOUTH
  OF POPLAR GROVE...AND MOVING NORTHEAST AT 55 MPH.

  AUTOMATED MEASURING EQUIPMENT AT THE ROCKFORD AIRPORT REPORTED     
  WIND GUSTS OF 55 MPH AT 317 PM WAS REPORTED WITH THESE STORMS.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  BELOIT AROUND 325 PM CDT.
  JANESVILLE AIRPORT AROUND 330 PM CDT.
  CLINTON AROUND 335 PM CDT.
  SHARON AROUND 340 PM CDT.
  WALWORTH AND DARIEN AROUND 345 PM CDT.
  WILLIAMS BAY...FONTANA-ON-GENEVA LAKE AND DELAVAN LAKE AROUND 350
  PM CDT.
  PELL LAKE...LAKE GENEVA...GENOA CITY AND COMO AROUND 355 PM CDT.

OTHER LOCATIONS IMPACTED BY THESE SEVERE THUNDERSTORMS INCLUDE
SHOPIERE...TIFFANY...AVALON...ALLENS GROVE...FONTANA...DELAVAN...
SPRING PRAIRIE AND SPRINGFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4250 8929 4263 8921 4267 8833 4249 8832
TIME...MOT...LOC 2020Z 244DEG 47KT 4248 8913 4224 8881
WIND...HAIL 70MPH 1.00IN

$$
MBK
3 follow-up statements
675 
WWUS53 KMKX 042031
SVSMKX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
331 PM CDT SAT AUG 4 2012

WIC105-127-042100-
/O.CON.KMKX.SV.W.0078.000000T0000Z-120804T2100Z/
WALWORTH WI-ROCK WI-
331 PM CDT SAT AUG 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHERN ROCK
AND SOUTHERN WALWORTH COUNTIES UNTIL 400 PM CDT...

AT 328 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DESTRUCTIVE WINDS IN EXCESS OF 70 MPH.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM BELOIT TO 9 MILES SOUTH OF
CAPRON...MOVING NORTHEAST AT 55 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  SHARON AROUND 340 PM CDT.
  WALWORTH AND DARIEN AROUND 345 PM CDT.
  WILLIAMS BAY...FONTANA-ON-GENEVA LAKE AND DELAVAN LAKE AROUND 350
  PM CDT.
  PELL LAKE...LAKE GENEVA...GENOA CITY AND COMO AROUND 355 PM CDT.

OTHER LOCATIONS IMPACTED BY SEVERE THUNDERSTORMS INCLUDE AVALON...
ALLENS GROVE...FONTANA...DELAVAN...SPRING PRAIRIE AND SPRINGFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4250 8929 4263 8921 4267 8833 4249 8832
TIME...MOT...LOC 2031Z 244DEG 47KT 4254 8895 4230 8863
WIND...HAIL 70MPH 1.00IN

$$

BROOKS
750 
WWUS53 KMKX 042045
SVSMKX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
345 PM CDT SAT AUG 4 2012

WIC105-127-042100-
/O.CON.KMKX.SV.W.0078.000000T0000Z-120804T2100Z/
WALWORTH WI-ROCK WI-
345 PM CDT SAT AUG 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHERN ROCK
AND SOUTHERN WALWORTH COUNTIES UNTIL 400 PM CDT...

AT 342 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM DARIEN TO 5 MILES WEST OF WONDER LAKE...MOVING NORTHEAST AT 55
MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  WILLIAMS BAY...FONTANA-ON-GENEVA LAKE AND DELAVAN LAKE AROUND 350
  PM CDT.
  PELL LAKE...LAKE GENEVA...GENOA CITY AND COMO AROUND 355 PM CDT.

OTHER LOCATIONS IMPACTED BY SEVERE THUNDERSTORMS INCLUDE FONTANA...
DELAVAN...SPRING PRAIRIE AND SPRINGFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 4250 8929 4263 8921 4267 8833 4249 8832
TIME...MOT...LOC 2045Z 244DEG 47KT 4262 8872 4238 8841
WIND...HAIL 60MPH <.75IN

$$

BROOKS
711 
WWUS53 KMKX 042056
SVSMKX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
356 PM CDT SAT AUG 4 2012

WIC105-127-042106-
/O.EXP.KMKX.SV.W.0078.000000T0000Z-120804T2100Z/
WALWORTH WI-ROCK WI-
356 PM CDT SAT AUG 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN ROCK AND SOUTHERN
WALWORTH COUNTIES WILL EXPIRE AT 400 PM CDT...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED AND MOVED
OUT OF THE WARNED AREA.

LAT...LON 4250 8929 4263 8921 4267 8833 4249 8832
TIME...MOT...LOC 2056Z 244DEG 47KT 4268 8854 4244 8823

$$

BROOKS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 3:21 PM CDTSpecial Marine WarningMKX77 min
Aug 4, 3:36 PM CDTSevere Thunderstorm WarningMKXGreen Lake9 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2012Every severe thunderstorm warning in 2012

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.