Alert archive / Iowa / Tornado Warnings in 2012

Tornado Warning 5, NWS La Crosse, WI

August 9, 2012Fayette County, Winneshiek County, Iowa

NWS La Crosse, WI issued this tornado warning at Aug 9, 2012, 4:55 PM CDT for Fayette County, Winneshiek County, Iowa. It was in force for 20 min. 6 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
Aug 9, 2012, 4:55 PM CDT (21:55 UTC)
Expired
Aug 9, 2012, 5:15 PM CDT
In force
20 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon

Counties Fayette County, IA, Winneshiek County, IA

The radar

The La Crosse radar (KARX), 96 km from the middle of the area, began a volume at 21:55 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
Aug 9, 4:55 PM CDTHAIL 14 E Ridgeway, IADIME TO QUARTER SIZED. ALSO SOME SMALL BRANCHES DOWNED FROM WIND.
Aug 9, 4:56 PM CDTHAIL 1.754 E Ridgeway, IAQUARTER TO GOLFBALL. DENTED CAMPER. WIND ESTIMATED AT 50 MPH WITH LEAVES SPRAYED ONTO SIDE OF HOUSE. NO DAMAGE TO HOME SIDING.
Aug 9, 4:56 PM CDTHAIL 22 W Decorah, IACOURTESY KWWL MEDIA. VERIFIED WITH PICTURE.
Aug 9, 5:05 PM CDTTSTM WND GST 70Conover, IA
Aug 9, 5:10 PM CDTTSTM WND GST 70Calmar, IACALMAR FIRE DEPARTMENT ESTIMATED A WIND GUST OF 70 MILES PER HOUR.
Aug 9, 5:10 PM CDTHAIL 12 Ne Calmar, IACOOPERATIVE OBSERVER MEASURED UP TO QUARTER SIZE HAIL. DRIFTS OF HAIL IN ROAD DITCH AND THE CORN WAS STRIPPED OF THE LEAVES WITH STALKS AND EARS LEFT.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.9 hours before the alert went out and 194 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 2012-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 351 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 2012-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
351 J/kg
Mixed-layer CIN
-94 J/kg
Mixed-layer LCL
646 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

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

864 
WFUS53 KARX 092155
TORARX
IAC065-191-092300-
/O.NEW.KARX.TO.W.0005.120809T2155Z-120809T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
455 PM CDT THU AUG 9 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHEASTERN FAYETTE COUNTY IN NORTHEAST IOWA...
  CENTRAL WINNESHIEK COUNTY IN NORTHEAST IOWA...

* UNTIL 600 PM CDT

* AT 450 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO NEAR STATE ROAD 9 AND 245TH STREET...OR 6 MILES WEST OF
  DECORAH...MOVING SOUTH AT 30 MPH. THIS TORNADO WARNING UPGRADES THE
  PREVIOUS SEVERE THUNDERSTORM WARNING FOR FAYETTE AND WINNESHIEK
  COUNTIES.

* THE TORNADO WILL BE NEAR...
  CONOVER AROUND 500 PM...
  CALMAR AND FORT ATKINSON AROUND 505 PM...
  OSSIAN AROUND 510 PM...
  FESTINA AROUND 515 PM...
  ST. LUCAS AROUND 520 PM...
  ELDORADO AND COUNTY ROADS W 42 AND B 40 AROUND 525 PM...
  DOUGLAS AROUND 530 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER IN A BASEMENT OR IN AN INTERIOR ROOM ON THE LOWEST FLOOR
AND STAY AWAY FROM WINDOWS! CARS AND MOBILE HOMES SHOULD BE ABANDONED
FOR A STURDY BUILDING. AS A LAST RESORT...LAY FLAT IN A DITCH AND
COVER YOUR HEAD.

&&

LAT...LON 4292 9161 4291 9193 4330 9200 4333 9182
TIME...MOT...LOC 2155Z 345DEG 25KT 4324 9190

$$

JW
2 follow-up statements
308 
WWUS53 KARX 092206
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
506 PM CDT THU AUG 9 2012

IAC065-191-092300-
/O.CON.KARX.TO.W.0005.000000T0000Z-120809T2300Z/
FAYETTE IA-WINNESHIEK IA-
506 PM CDT THU AUG 9 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL WINNESHIEK
AND NORTHEASTERN FAYETTE COUNTIES UNTIL 600 PM CDT...

AT 503 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
POSSIBLE TORNADO LOCATED NEAR CALMAR...OR 9 MILES SOUTHWEST OF 
DECORAH...MOVING SOUTH AT 30 MPH. IN ADDITION TO A TORNADO...THIS 
STORM CAN PRODUCE QUARTER SIZE HAIL.

* THE TORNADO WILL BE NEAR...
  OSSIAN AROUND 510 PM...
  FESTINA AROUND 515 PM...
  ST. LUCAS AROUND 520 PM...
  ELDORADO AROUND 525 PM...
  COUNTY ROADS W 42 AND B 40 AND DOUGLAS AROUND 530 PM...
  WEST UNION AROUND 535 PM...
  ELGIN AND BRAINARD AROUND 545 PM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER IN A BASEMENT OR IN AN INTERIOR ROOM ON THE LOWEST FLOOR
AND STAY AWAY FROM WINDOWS! CARS AND MOBILE HOMES SHOULD BE ABANDONED
FOR A STURDY BUILDING. AS A LAST RESORT...LAY FLAT IN A DITCH AND
COVER YOUR HEAD.

&&

LAT...LON 4292 9161 4291 9193 4321 9196 4323 9180
TIME...MOT...LOC 2206Z 345DEG 25KT 4317 9186

$$

JW
066 
WWUS53 KARX 092215
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
515 PM CDT THU AUG 9 2012

IAC065-191-092224-
/O.CAN.KARX.TO.W.0005.000000T0000Z-120809T2300Z/
FAYETTE IA-WINNESHIEK IA-
515 PM CDT THU AUG 9 2012

...THE TORNADO WARNING FOR SOUTH CENTRAL WINNESHIEK AND NORTHEASTERN
FAYETTE COUNTIES IS CANCELLED...

THE TORNADO THREAT HAS DIMINISHED...THEREFORE THE TORNADO WARNING HAS
BEEN CANCELLED. HOWEVER...A SEVERE THUNDERSTORM WARNING REMAINS IN 
EFFECT FOR SOUTHERN WINNESHIEK AND NORTHERN FAYETTE COUNTIES.

LAT...LON 4292 9161 4291 9193 4321 9196 4323 9180
TIME...MOT...LOC 2214Z 345DEG 25KT 4312 9184

$$

JW

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 7:08 PM CDTSevere Thunderstorm WarningARXChickasaw, Howard52 min
Aug 9, 4:49 PM CDTSevere Thunderstorm WarningARXFayette, Winneshiek56 min

Nearby

Tornado Warnings in Iowa, 2012Every tornado warning in 2012Tornadoes 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.