Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 277, NWS Twin Cities, MN

September 4, 2012Eau Claire County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 4, 2012, 5:06 PM CDT for Eau Claire County, Wisconsin. It was in force for 39 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, 5:06 PM CDT (22:06 UTC)
Expired
Sep 4, 2012, 5:45 PM CDT
In force
39 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Eau Claire County, WI

The radar

The La Crosse radar (KARX), 90 km from the middle of the area, began a volume at 22:06 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, 5:46 PM CDTHAIL 1.753 S Fall Creek, WI
Sep 4, 5:46 PM CDTHAIL 23 S Fall Creek, 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

Minneapolis, MN (KMPX), launched 12:00Z, 10.1 hours before the alert went out and 185 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, Minneapolis, MN at 12:00Z on 2012-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1446 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, Minneapolis, MN at 12:00Z on 2012-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 172 square meters per square second.19395878Sfc1 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
1446 J/kg
Mixed-layer CIN
-171 J/kg
Mixed-layer LCL
1471 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
172 m²/s²
0-3 km storm-relative helicity
221 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.8

Open this sounding in Storm Lab

The text

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

191 
WUUS53 KMPX 042206
SVRMPX
WIC035-042245-
/O.NEW.KMPX.SV.W.0277.120904T2206Z-120904T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
506 PM CDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN EAU CLAIRE COUNTY IN WEST CENTRAL WISCONSIN...

* UNTIL 545 PM CDT

* AT 504 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM...CAPABLE OF
  PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS OF 60 MPH. THIS
  STORM WAS LOCATED 5 MILES NORTHWEST OF STRUM...OR ABOUT 11 MILES
  EAST OF MONDOVI...AND MOVING EAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  ALLEN...
  BRACKETT...
  FOSTER...
  AUGUSTA...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR
DAMAGING WINDS IN EXCESS OF 60 MPH AND LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

&&

LAT...LON 4459 9128 4459 9129 4459 9149 4469 9153
      4477 9107 4459 9101
TIME...MOT...LOC 2206Z 258DEG 21KT 4462 9143
WIND...HAIL 60MPH 1.00IN

$$
2 follow-up statements
928 
WWUS53 KMPX 042221
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
521 PM CDT TUE SEP 4 2012

WIC035-042245-
/O.CON.KMPX.SV.W.0277.000000T0000Z-120904T2245Z/
EAU CLAIRE WI-
521 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHERN EAU
CLAIRE COUNTY IN WEST CENTRAL WISCONSIN UNTIL 545 PM CDT...

AT 518 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS OF 60 MPH.  THIS
STORM WAS LOCATED 7 MILES NORTH OF STRUM...OR 14 MILES SOUTHEAST OF
EAU CLAIRE...MOVING EAST AT 25 MPH. NICKEL SIZE HAIL MAY ALSO
ACCOMPANY THESE DAMAGING WINDS.

LOCATIONS IMPACTED INCLUDE...
  AUGUSTA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...HAIL...AND DEADLY LIGHTNING. FOR YOUR PROTECTION MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS.

&&

LAT...LON 4459 9139 4470 9148 4477 9107 4459 9101
TIME...MOT...LOC 2221Z 253DEG 21KT 4465 9131
WIND...HAIL 60MPH 0.88IN

$$
367 
WWUS53 KMPX 042238
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
538 PM CDT TUE SEP 4 2012

WIC035-042253-
/O.EXP.KMPX.SV.W.0277.000000T0000Z-120904T2245Z/
EAU CLAIRE WI-
538 PM CDT TUE SEP 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN EAU CLAIRE COUNTY IN
WEST CENTRAL WISCONSIN WILL EXPIRE AT 545 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

THIS STORM HAS MERGED WITH A STORM OVER CENTRAL EAU CLAIRE COUNTY THAT
IS COVER IS SEVERE THUNDERSTORM WARNING NUMBER 278.

LAT...LON 4459 9139 4470 9148 4477 9107 4459 9101
TIME...MOT...LOC 2238Z 253DEG 21KT 4468 9118

$$

LS

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 4, 3:55 PM CDTSpecial Weather StatementMPXChippewa50 min
Sep 4, 4:17 PM CDTSevere Thunderstorm WarningMPXBarron, Chippewa, Rusk43 min
Sep 4, 4:55 PM CDTSevere Thunderstorm WarningMPXChippewa50 min
Sep 4, 5:19 PM CDTSevere Thunderstorm WarningMPXEau Claire26 min
Sep 4, 5:39 PM CDTSevere Thunderstorm WarningMPXChippewa, Eau Claire36 min
Sep 4, 6:11 PM CDTSevere Thunderstorm WarningMPXEau Claire30 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.