Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 104, NWS La Crosse, WI

September 4, 2012Crawford County, Grant County, Wisconsin; Allamakee County, Clayton County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Sep 4, 2012, 6:37 PM CDT for Crawford County, Grant County, Wisconsin; Allamakee County, Clayton County, Iowa. It was in force for 38 min. 2 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
Sep 4, 2012, 6:37 PM CDT (23:37 UTC)
Expired
Sep 4, 2012, 7:15 PM CDT
In force
38 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Hail
1.75 in
Wind
60.0 mph

Counties Allamakee County, IA, Clayton County, IA, Crawford County, WI, Grant County, WI

The radar

The La Crosse radar (KARX), 88 km from the middle of the area, began a volume at 23:37 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

TimeReportWhereRemark
Sep 4, 6:46 PM CDTHAIL 1.25Prairie Du Chien, WI
Sep 4, 6:56 PM CDTHAIL 1Brodtville, WI

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.

IssuedProductOfficeLasted
Sep 4, 3:27 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.6 hours before the alert went out and 165 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 2012-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1827 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 2012-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939587897Sfc1 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
1827 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
971 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

735 
WUUS53 KARX 042337
SVRARX
IAC005-043-WIC023-043-050015-
/O.NEW.KARX.SV.W.0104.120904T2337Z-120905T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
637 PM CDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN ALLAMAKEE COUNTY IN NORTHEAST IOWA...
  NORTH CENTRAL CLAYTON COUNTY IN NORTHEAST IOWA...
  SOUTHWESTERN CRAWFORD COUNTY IN SOUTHWEST WISCONSIN...
  WEST CENTRAL GRANT COUNTY IN SOUTHWEST WISCONSIN...

* UNTIL 715 PM CDT

* AT 632 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM LOCATED NEAR EFFIGY MOUNDS...OR NEAR PRAIRIE DU
  CHIEN...MOVING SOUTHEAST AT 15 MPH. THIS STORM CAN PRODUCE LARGE
  DAMAGING HAIL UP TO GOLF BALL SIZE AND DAMAGING WINDS IN EXCESS OF
  60 MPH. TRAINED WEATHER SPOTTERS HAVE ALREADY REPORTED GOLF BALL   
  SIZE HAIL WITH THIS STORM IN MARQUETTE IOWA.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  PRAIRIE DU CHIEN AND MCGREGOR AROUND 645 PM...
  WYALUSING STATE PARK AND IRISH RIDGE AROUND 700 PM...
  BRIDGEPORT AND CLAYTON AROUND 705 PM...
  JELLYSTONE PARK NEAR BAGLEY AROUND 710 PM...
  BRODTVILLE AND BAGLEY AROUND 715 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. IF YOU ARE IN THE PATH OF THIS
STORM...PREPARE IMMEDIATELY FOR DESTRUCTIVE HAIL...WHICH CAN
SIGNIFICANTLY DAMAGE ROOFS...WINDOWS...SIDING AND VEHICLES. DAMAGING
WINDS ARE ALSO EXPECTED...WHICH WILL UPROOT TREES AND DOWN POWER
LINES. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4305 9089 4287 9113 4307 9132 4315 9121
TIME...MOT...LOC 2337Z 306DEG 14KT 4306 9119
WIND...HAIL 60MPH 1.75IN

$$

AJ
3 follow-up statements
573 
WWUS53 KARX 042350
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
650 PM CDT TUE SEP 4 2012

IAC005-043-WIC023-043-050015-
/O.CON.KARX.SV.W.0104.000000T0000Z-120905T0015Z/
ALLAMAKEE IA-CLAYTON IA-CRAWFORD WI-GRANT WI-
650 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR WEST CENTRAL
GRANT...SOUTHWESTERN CRAWFORD...NORTH CENTRAL CLAYTON AND
SOUTHEASTERN ALLAMAKEE COUNTIES UNTIL 715 PM CDT...

AT 646 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE 
SEVERE THUNDERSTORM WAS LOCATED NEAR PRAIRIE DU CHIEN...MOVING 
SOUTHEAST AT 15 MPH. LOCAL LAW ENFORCEMENT OFFICIALS JUST REPORTED 
HALF DOLLAR SIZE HAIL IN PRAIRIE DU CHIEN. THIS STORM CAN PRODUCE 
LARGE DAMAGING HAIL UP TO GOLF BALL SIZE...THOUGH...AND DAMAGING 
WINDS IN EXCESS OF 60 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WYALUSING STATE PARK AND IRISH RIDGE AROUND 700 PM...
  BRIDGEPORT AND CLAYTON AROUND 705 PM...
  JELLYSTONE PARK NEAR BAGLEY AROUND 710 PM...
  BRODTVILLE AND BAGLEY AROUND 715 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. IF YOU ARE IN THE PATH OF THIS
STORM...PREPARE IMMEDIATELY FOR DESTRUCTIVE HAIL...WHICH CAN
SIGNIFICANTLY DAMAGE ROOFS...WINDOWS...SIDING AND VEHICLES. DAMAGING
WINDS ARE ALSO EXPECTED...WHICH WILL UPROOT TREES AND DOWN POWER
LINES. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4305 9089 4287 9113 4298 9124 4307 9132
      4315 9121
TIME...MOT...LOC 2349Z 306DEG 14KT 4303 9114
WIND...HAIL 60MPH 1.75IN

$$

AJ
696 
WWUS53 KARX 050002 RRA
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
702 PM CDT TUE SEP 4 2012

IAC005-050012-
/O.CAN.KARX.SV.W.0104.000000T0000Z-120905T0015Z/
ALLAMAKEE IA-
702 PM CDT TUE SEP 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ALLAMAKEE COUNTY
IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT THE WARNED AREA. 
HOWEVER...ANOTHER WARNING WILL BE ISSUED SHORTLY FOR SOUTHEASTERN 
ALLAMAKEE COUNTY.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT
TUESDAY EVENING FOR NORTHEASTERN IOWA AND SOUTHEAST MINNESOTA AND
WESTERN WISCONSIN.

LAT...LON 4295 9116 4300 9118 4310 9105 4305 9089
      4287 9113
TIME...MOT...LOC 0002Z 306DEG 14KT 4300 9108

$$

IAC043-WIC023-043-050015-
/O.CON.KARX.SV.W.0104.000000T0000Z-120905T0015Z/
CLAYTON IA-CRAWFORD WI-GRANT WI-
702 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR WEST CENTRAL
GRANT...SOUTHWESTERN CRAWFORD AND EAST CENTRAL CLAYTON COUNTIES UNTIL
715 PM CDT...

AT 700 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR WYALUSING STATE PARK...OR NEAR
PRAIRIE DU CHIEN...MOVING SOUTHEAST AT 15 MPH. THIS STORM CAN PRODUCE
LARGE DAMAGING HAIL UP TO GOLF BALL SIZE AND DAMAGING WINDS IN EXCESS
OF 60 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  JELLYSTONE PARK NEAR BAGLEY AROUND 710 PM...
  BRODTVILLE AND BAGLEY AROUND 715 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. IF YOU ARE IN THE PATH OF THIS
STORM...PREPARE IMMEDIATELY FOR DESTRUCTIVE HAIL...WHICH CAN
SIGNIFICANTLY DAMAGE ROOFS...WINDOWS...SIDING AND VEHICLES. DAMAGING
WINDS ARE ALSO EXPECTED...WHICH WILL UPROOT TREES AND DOWN POWER
LINES. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4295 9116 4300 9118 4310 9105 4305 9089
      4287 9113
TIME...MOT...LOC 0002Z 306DEG 14KT 4300 9108
WIND...HAIL 60MPH 1.75IN

$$

AJ
242 
WWUS53 KARX 050017
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
717 PM CDT TUE SEP 4 2012

IAC043-WIC023-043-050026-
/O.EXP.KARX.SV.W.0104.000000T0000Z-120905T0015Z/
CLAYTON IA-CRAWFORD WI-GRANT WI-
717 PM CDT TUE SEP 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL GRANT...
SOUTHWESTERN CRAWFORD AND EAST CENTRAL CLAYTON COUNTIES HAS
EXPIRED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA. HOWEVER...ANOTHER SEVERE THUNDERSTORM WARNING WILL LIKELY BE 
REQUIRED FOR NORTHERN GRANT COUNTY WITH STORMS DROPPING SOUTH 
THROUGH CRAWFORD AND RICHLAND COUNTIES.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT 
TUESDAY EVENING FOR NORTHEASTERN IOWA AND SOUTHWESTERN WISCONSIN.

LAT...LON 4295 9116 4300 9118 4310 9105 4305 9089
      4287 9113
TIME...MOT...LOC 0002Z 306DEG 14KT 4300 9108

$$

AJ

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 4:39 AM CDTDense Fog AdvisoryARXAdams, Buffalo, Clark, Crawford, Grant, Jackson and 7 more4 hr
Sep 4, 4:29 PM CDTSevere Thunderstorm WarningARXBuffalo46 min
Sep 4, 5:17 PM CDTSevere Thunderstorm WarningARXVernon28 min
Sep 4, 5:41 PM CDTSevere Thunderstorm WarningARXClark64 min
Sep 4, 5:56 PM CDTSevere Thunderstorm WarningARXLa Crosse, Vernon64 min
Sep 4, 6:16 PM CDTSevere Thunderstorm WarningARXClark29 min
Sep 4, 6:48 PM CDTSevere Thunderstorm WarningARXCrawford, Vernon57 min
Sep 4, 6:09 PM CDTSevere Thunderstorm WarningARXAllamakee, Clayton36 min
Sep 4, 6:38 PM CDTSevere Thunderstorm WarningARXAllamakee52 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2012Severe Thunderstorm Warnings in Iowa, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.