Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 112, NWS La Crosse, WI

September 4, 2012Clayton County, Fayette County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Sep 4, 2012, 10:10 PM CDT for Clayton County, Fayette County, Iowa. It was in force for 65 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, 10:10 PM CDT (03:10 UTC)
Expired
Sep 4, 2012, 11:15 PM CDT
In force
65 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Clayton County, IA, Fayette County, IA

The radar

The La Crosse radar (KARX), 107 km from the middle of the area, began a volume at 03:13 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, 11:00 PM CDTHAIL 16 Ssw Elkader, IA
Sep 4, 11:05 PM CDTHAIL 1.5Osborne, IAOFF-DUTY DISPATCHER REPORTS HAIL ABOUT PING-PONG BALL SIZE

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 00:00Z, 3.2 hours before the alert went out and 160 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 00:00Z on 2012-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1890 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 00:00Z on 2012-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 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
1890 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
1662 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.9

Open this sounding in Storm Lab

The text

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

641 
WUUS53 KARX 050310
SVRARX
IAC043-065-050415-
/O.NEW.KARX.SV.W.0112.120905T0310Z-120905T0415Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
1010 PM CDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLAYTON COUNTY IN NORTHEAST IOWA...
  EAST CENTRAL FAYETTE COUNTY IN NORTHEAST IOWA...

* UNTIL 1115 PM CDT

* AT 1009 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM LOCATED NEAR GUNDER...OR 10 MILES NORTHWEST OF
  ELKADER...MOVING SOUTHEAST AT 15 MPH. THIS STORM CAN PRODUCE
  QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH.  

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WADENA AROUND 1020 PM...
  HIGHWAY 56 AND COUNTY W 70 AROUND 1030 PM...
  ST. OLAF AROUND 1035 PM...
  VOLGA AROUND 1045 PM...
  ELKADER AND THOMASVILLE AROUND 1050 PM...
  CLAYTON CENTER AND SAINT SEBALD AROUND 1055 PM...
  OSBORNE AROUND 1100 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4284 9119 4269 9160 4297 9172 4304 9151
TIME...MOT...LOC 0310Z 321DEG 12KT 4294 9156
WIND...HAIL 60MPH 1.00IN

$$

JW
4 follow-up statements
619 
WWUS53 KARX 050331
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1031 PM CDT TUE SEP 4 2012

IAC043-065-050415-
/O.CON.KARX.SV.W.0112.000000T0000Z-120905T0415Z/
FAYETTE IA-CLAYTON IA-
1031 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CLAYTON AND
EAST CENTRAL FAYETTE COUNTIES UNTIL 1115 PM CDT...

AT 1026 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR HIGHWAY 56 AND COUNTY W 70...OR 6
MILES NORTHWEST OF ELKADER...MOVING SOUTHEAST AT 15 MPH. THIS STORM
CAN PRODUCE QUARTER SIZE HAIL.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ST. OLAF AROUND 1035 PM...
  VOLGA AROUND 1045 PM...
  ELKADER AND THOMASVILLE AROUND 1050 PM...
  CLAYTON CENTER AROUND 1055 PM...
  OSBORNE AND SAINT SEBALD AROUND 1100 PM...
  HIGHWAY 13 AND COUNTY C 24 AROUND 1105 PM...
  COMMUNIA AND MEDERVILLE AROUND 1110 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4294 9167 4300 9149 4284 9119 4269 9160
TIME...MOT...LOC 0331Z 321DEG 12KT 4289 9150
WIND...HAIL <50MPH 1.00IN

$$

JW
237 
WWUS53 KARX 050335
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1035 PM CDT TUE SEP 4 2012

IAC043-065-050415-
/O.CON.KARX.SV.W.0112.000000T0000Z-120905T0415Z/
FAYETTE IA-CLAYTON IA-
1035 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CLAYTON AND
EAST CENTRAL FAYETTE COUNTIES UNTIL 1115 PM CDT...

AT 1030 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR HIGHWAY 56 AND COUNTY W 70...OR NEAR
ELKADER...MOVING SOUTHEAST AT 15 MPH. THIS STORM CAN PRODUCE PING
PONG BALL SIZE HAIL.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  VOLGA AROUND 1045 PM...
  ELKADER AND THOMASVILLE AROUND 1050 PM...
  CLAYTON CENTER AROUND 1055 PM...
  OSBORNE AND SAINT SEBALD AROUND 1100 PM...
  HIGHWAY 13 AND COUNTY C 24 AROUND 1105 PM...
  MEDERVILLE AND MOTOR AROUND 1110 PM...
  COMMUNIA AROUND 1115 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4294 9167 4300 9149 4284 9119 4269 9160
TIME...MOT...LOC 0335Z 321DEG 12KT 4288 9149
WIND...HAIL <50MPH 1.50IN

$$

JW
979 
WWUS53 KARX 050346
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1046 PM CDT TUE SEP 4 2012

IAC043-065-050415-
/O.CON.KARX.SV.W.0112.000000T0000Z-120905T0415Z/
FAYETTE IA-CLAYTON IA-
1046 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CLAYTON AND
EXTREME EAST CENTRAL FAYETTE COUNTIES UNTIL 1115 PM CDT...

AT 1043 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR ELKADER...MOVING SOUTHEAST AT 15 
MPH. THIS STORM CAN PRODUCE PING PONG BALL SIZE HAIL. IN ADDITION 
THIS STORM IS CAPABLE OF PRODUCING LARGE QUANTITIES OF HAIL THAT MAY 
COVER ROADWAYS. 

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  ELKADER AND THOMASVILLE AROUND 1055 PM...
  OSBORNE AND CLAYTON CENTER AROUND 1100 PM...
  HIGHWAY 13 AND COUNTY C 24 AROUND 1105 PM...
  MEDERVILLE AND MOTOR AROUND 1110 PM...
  COMMUNIA AROUND 1115 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

TORRENTIAL RAINFALL FROM THIS STORM MAY ALSO CAUSE THE PONDING OF 
WATER ON ROADWAYS AND LOCALIZED FLOODING.

&&

LAT...LON 4294 9164 4298 9148 4284 9119 4269 9160
TIME...MOT...LOC 0345Z 321DEG 12KT 4285 9146
WIND...HAIL <50MPH 1.50IN

$$

JW
165 
WWUS53 KARX 050400
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1100 PM CDT TUE SEP 4 2012

IAC065-050410-
/O.CAN.KARX.SV.W.0112.000000T0000Z-120905T0415Z/
FAYETTE IA-
1100 PM CDT TUE SEP 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL FAYETTE COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 4293 9161 4293 9144 4284 9119 4269 9160
TIME...MOT...LOC 0400Z 321DEG 12KT 4281 9142

$$

IAC043-050415-
/O.CON.KARX.SV.W.0112.000000T0000Z-120905T0415Z/
CLAYTON IA-
1100 PM CDT TUE SEP 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHERN
CLAYTON COUNTY UNTIL 1115 PM CDT...

AT 1055 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR OSBORNE...OR NEAR ELKADER...MOVING
SOUTHEAST AT 15 MPH. THIS STORM CAN PRODUCE PING PONG BALL SIZE HAIL.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MEDERVILLE AND MOTOR AROUND 1110 PM...
  COMMUNIA AROUND 1115 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

TORRENTIAL RAINFALL FROM THESE STORMS MAY ALSO CAUSE THE PONDING OF
WATER ON ROADWAYS AND LOCALIZED FLOODING.

&&

LAT...LON 4293 9161 4293 9144 4284 9119 4269 9160
TIME...MOT...LOC 0400Z 321DEG 12KT 4281 9142
WIND...HAIL <50MPH 1.50IN

$$

JW

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 7:06 PM CDTSevere Thunderstorm WarningARXAllamakee24 min
Sep 4, 7:35 PM CDTSevere Thunderstorm WarningARXClayton70 min
Sep 4, 8:09 PM CDTFlash Flood WarningARXAllamakee, Clayton6 hr
Sep 4, 10:42 PM CDTSevere Thunderstorm WarningARXAllamakee, Winneshiek33 min
Sep 4, 11:09 PM CDTFlash Flood WarningARXAllamakee, Winneshiek5 hr
Sep 4, 11:14 PM CDTSevere Thunderstorm WarningARXClayton46 min
Sep 4, 11:36 PM CDTSevere Thunderstorm WarningARXAllamakee, Clayton, Fayette, Winneshiek47 min
Sep 4, 11:59 PM CDTSevere Thunderstorm WarningARXClayton61 min
Sep 5, 12:12 AM CDTSevere Thunderstorm WarningARXFloyd, Mitchell63 min
Sep 5, 12:31 AM CDTSevere Thunderstorm WarningARXChickasaw, Howard44 min
Sep 5, 1:06 AM CDTSevere Thunderstorm WarningARXFayette, Winneshiek24 min
Sep 5, 1:28 AM CDTSevere Thunderstorm WarningARXAllamakee32 min
Sep 5, 1:51 AM CDTFlash Flood WarningARXClayton, Fayette3 hr
Sep 5, 1:59 AM CDTFlash Flood WarningARXAllamakee, Clayton3 hr

Nearby

Severe 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.