Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 78, NWS La Crosse, WI

July 25, 2012Clayton County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at Jul 25, 2012, 10:25 PM CDT for Clayton County, Iowa. It was in force for 65 min. 3 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
Jul 25, 2012, 10:25 PM CDT (03:25 UTC)
Expired
Jul 25, 2012, 11:30 PM CDT
In force
65 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Clayton County, IA

The radar

The La Crosse radar (KARX), 107 km from the middle of the area, began a volume at 03:28 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
Jul 25, 10:25 PM CDTTSTM WND DMGElkader, IASUMMARY FROM CLAYTON COUNTY LAW ENFORCEMENT. 17 REPORTS OF POWER LINES DOWN ACROSS COUNTY. AT LEAST 30 REPORTS OF TREES DOWN. 1 ONE INCH HAIL REPORT IN GUTTENBERG
Jul 25, 10:48 PM CDTTSTM WND DMGEdgewood, IAPOWER OUT ACROSS TOWN. A FEW TREE BRANCHES DOWN
Jul 25, 10:50 PM CDTTSTM WND GST 43Edgewood, IAMEASURED AT THE FIRE DEPT

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
Jul 25, 5:16 PM CDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.4 hours before the alert went out and 150 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 2012-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 700 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 2012-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 84 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
700 J/kg
Mixed-layer CIN
-149 J/kg
Mixed-layer LCL
2702 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
84 m²/s²
0-3 km storm-relative helicity
158 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

628 
WUUS53 KARX 260325
SVRARX
IAC043-260430-
/O.NEW.KARX.SV.W.0078.120726T0325Z-120726T0430Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
1025 PM CDT WED JUL 25 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CLAYTON COUNTY IN NORTHEAST IOWA...

* UNTIL 1130 PM CDT

* AT 1023 PM...DOPPLER RADAR INDICATED SEVERE THUNDERSTORMS ROUGHLY
  ALONG A LINE EXTENDING FROM WEST UNION TO ARLINGTON TO 
  STANLEY...MOVING EAST AT 40 MPH. THESE STORMS CAN PRODUCE
  QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH.  

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  VOLGA AROUND 1035 PM...
  STRAWBERRY POINT AROUND 1040 PM...
  ELKADER AND EDGEWOOD AROUND 1050 PM...
  FARMERSBURG AND MONONA AROUND 1055 PM...
  GARNAVILLO AROUND 1100 PM...
  GUTTENBERG AND MCGREGOR AROUND 1110 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4308 9160 4308 9118 4297 9116 4297 9115
      4291 9115 4288 9110 4275 9107 4268 9095
      4268 9090 4265 9090 4264 9160
TIME...MOT...LOC 0325Z 270DEG 33KT 4296 9177 4282 9167
          4268 9172
WIND...HAIL 60MPH 1.00IN

$$

SHEA
3 follow-up statements
418 
WWUS53 KARX 260344
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1044 PM CDT WED JUL 25 2012

IAC043-260430-
/O.CON.KARX.SV.W.0078.000000T0000Z-120726T0430Z/
CLAYTON IA-
1044 PM CDT WED JUL 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CLAYTON COUNTY
UNTIL 1130 PM CDT...

AT 1042 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WERE ROUGHLY ALONG A LINE EXTENDING FROM FARMERSBURG TO
ELKADER TO EDGEWOOD...MOVING EAST AT 45 MPH. THESE STORMS CAN PRODUCE
QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH...
ESPECIALLY IN THE ELKADER AREA WHERE THE WIND LOOKS STRONGEST 
ON RADAR.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  GARNAVILLO AND FARMERSBURG AROUND 1050 PM...
  GUTTENBERG AROUND 1100 PM...
  MCGREGOR AND MARQUETTE AROUND 1105 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXPECT STRONG WIND GUSTS...HAIL AND HEAVY RAIN WITH THESE STORMS.
STAY INDOORS.

&&

LAT...LON 4308 9160 4308 9118 4297 9116 4297 9115
      4291 9115 4288 9110 4275 9107 4268 9095
      4268 9090 4265 9090 4264 9160
TIME...MOT...LOC 0343Z 269DEG 39KT 4297 9147 4284 9136
          4269 9143
WIND...HAIL 60MPH 1.00IN

$$

SHEA
150 
WWUS53 KARX 260359
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1059 PM CDT WED JUL 25 2012

IAC043-260430-
/O.CON.KARX.SV.W.0078.000000T0000Z-120726T0430Z/
CLAYTON IA-
1059 PM CDT WED JUL 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CLAYTON COUNTY
UNTIL 1130 PM CDT...

AT 1055 PM...RADAR INDICATED A LARGE AREA OF THUNDERSTORMS OVER 
MAINLY CENTRAL CLAYTON COUNTY...AROUND ELKADER OVER TO GARNAVILLO.
THESE STORMS CAN PRODUCE DAMAGING WINDS IN EXCESS OF 60 MPH AND 
CONTINUE TO MOVE EAST TOWARDS THE MISSISSIPPI RIVER.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  RURAL EASTERN CLAYTON COUNTY THROUGH 1110 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BESIDES DOWNED TREES AND STRONG WINDS...BE ALERT FOR LOCALIZED 
FLOODING AND RAPID RISES IN WATER DRAINAGE AREAS.

&&

LAT...LON 4303 9151 4308 9118 4300 9117 4297 9115
      4291 9115 4288 9110 4275 9107 4268 9095
      4268 9090 4265 9090 4264 9159
TIME...MOT...LOC 0358Z 269DEG 39KT 4297 9125 4284 9114
          4269 9121
WIND...HAIL 60MPH <.50IN

$$

SHEA
475 
WWUS53 KARX 260423
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
1123 PM CDT WED JUL 25 2012

IAC043-260432-
/O.EXP.KARX.SV.W.0078.000000T0000Z-120726T0430Z/
CLAYTON IA-
1123 PM CDT WED JUL 25 2012

...THE SEVERE THUNDERSTORM WARNING FOR CLAYTON COUNTY WILL EXPIRE AT
1130 PM CDT...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED AND MOVED
OUT OF THE WARNED AREA. THUNDERSTORMS WITH HEAVY RAIN AND FREQUENT 
LIGHTNING REMAIN IN THE AREA THOUGH SO REMAIN INDOORS. BE ALERT FOR 
LOCALIZED FLOODING PROBLEMS THROUGH 2 AM SINCE 1 TO 2 INCHES OF RAIN 
MAY FALL.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM.

LAT...LON 4303 9151 4308 9118 4300 9117 4297 9115
      4291 9115 4288 9110 4275 9107 4268 9095
      4268 9090 4265 9090 4264 9159
TIME...MOT...LOC 0422Z 269DEG 39KT 4297 9089 4284 9078
          4269 9086

$$

SHEA

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 8:38 PM CDTSevere Thunderstorm WarningARXClayton22 min
Jul 25, 9:40 PM CDTSevere Thunderstorm WarningARXChickasaw35 min
Jul 25, 10:03 PM CDTSevere Thunderstorm WarningARXFayette, Winneshiek43 min
Jul 25, 10:55 PM CDTAreal Flood AdvisoryARXFayette84 min

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.