Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 27, NWS La Crosse, WI

May 5, 2012Chickasaw County, Floyd County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at May 5, 2012, 4:29 PM CDT for Chickasaw County, Floyd County, Iowa. It was in force for 43 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
May 5, 2012, 4:29 PM CDT (21:29 UTC)
Expired
May 5, 2012, 5:12 PM CDT
In force
43 min
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Hail
1.75 in
Wind
60.0 mph

Counties Chickasaw County, IA, Floyd County, IA

The radar

The La Crosse radar (KARX), 143 km from the middle of the area, began a volume at 21:28 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
May 5, 4:29 PM CDTHAIL 0.88Charles City, IARELAYED BY KCHA
May 5, 4:30 PM CDTHAIL 0.75Charles City, IA
May 5, 4:50 PM CDTHAIL 0.252 Sw Nashua, IAISU AG FARM-ALSO 0.82 RAIN VERY SHORT PERIOD OF TIME

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
May 5, 11:38 AM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 9.5 hours before the alert went out and 216 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 2012-05-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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 2012-05-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 174 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
480 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
174 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

435 
WUUS53 KARX 052129
SVRARX
IAC037-067-052230-
/O.NEW.KARX.SV.W.0027.120505T2129Z-120505T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
429 PM CDT SAT MAY 5 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN FLOYD COUNTY IN NORTH CENTRAL IOWA...
  WESTERN CHICKASAW COUNTY IN NORTHEAST IOWA...

* UNTIL 530 PM CDT

* AT 424 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM LOCATED NEAR CHARLES CITY...MOVING SOUTHEAST AT
  25 MPH. THIS STORM CAN PRODUCE LARGE DAMAGING HAIL UP TO GOLF BALL 
  SIZE AND DAMAGING WINDS IN EXCESS OF 60 MPH. TRAINED SPOTTERS      
  REPORTED GOLF BALL SIZE HAIL NEAR THE FLOYD COUNTY FAIRGROUNDS IN  
  CHARLES CITY. THIS WARNING EXTENDS THE PREVIOUS SEVERE             
  THUNDERSTORM WARNING FOR FLOYD AND CHICKASAW   COUNTIES.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MIDWAY AND CARRVILLE AROUND 435 PM...
  HOWARDS WOOD RECREATIONAL AREA AND BASSETT AROUND 440 PM...
  NASHUA AND BRADFORD AROUND 445 PM...
  IONIA AND HIGHWAY 18 AND COUNTY V 18 AROUND 450 PM...  
  NEW HAMPTON AND WILLIAMSTOWN AROUND 505 PM...
  BOYD AROUND 510 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.

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

&&

LAT...LON 4319 9270 4317 9223 4290 9224 4290 9282
      4291 9293
TIME...MOT...LOC 2127Z 295DEG 22KT 4303 9267
WIND...HAIL 60MPH 1.75IN

$$

DTJ
3 follow-up statements
901 
WWUS53 KARX 052146
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
446 PM CDT SAT MAY 5 2012

IAC037-067-052230-
/O.CON.KARX.SV.W.0027.000000T0000Z-120505T2230Z/
FLOYD IA-CHICKASAW IA-
446 PM CDT SAT MAY 5 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR WESTERN
CHICKASAW AND SOUTHEASTERN FLOYD COUNTIES UNTIL 530 PM CDT...

BROAD CAST MEDIA REPORTED NICKLE SIZE HAIL IN CHARLES CITY AT 429 PM 
AND BROADCAST MEDIA REPORTED PENNY SIZE HAIL IN CHARLES CITY AT 430 
PM.

AT 442 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR BRADFORD...OR 10 MILES SOUTHEAST OF
CHARLES CITY...MOVING EAST AT 40 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...
  TWIN PONDS PARK AND NEW HAMPTON AIRPORT AROUND 450 PM...
  NEW HAMPTON AND REPUBLIC AROUND 455 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.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT. CONDITIONS REMAIN
FAVORABLE FOR ADDITIONAL SEVERE THUNDERSTORMS TO DEVELOP.

&&

LAT...LON 4317 9255 4312 9232 4290 9224 4291 9272
TIME...MOT...LOC 2145Z 289DEG 34KT 4297 9249
WIND...HAIL 60MPH 1.75IN

$$

DTJ
738 
WWUS53 KARX 052157
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
457 PM CDT SAT MAY 5 2012

IAC037-067-052230-
/O.CON.KARX.SV.W.0027.000000T0000Z-120505T2230Z/
FLOYD IA-CHICKASAW IA-
457 PM CDT SAT MAY 5 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHWESTERN
CHICKASAW AND SOUTHEASTERN FLOYD COUNTIES UNTIL 530 PM CDT...

AT 452 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR NASHUA...OR 13 MILES SOUTHWEST OF
NEW HAMPTON...MOVING SOUTHEAST AT 25 MPH. THIS STORM CAN PRODUCE
QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  WILLIAMSTOWN AROUND 505 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.

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT. CONDITIONS REMAIN
FAVORABLE FOR ADDITIONAL SEVERE THUNDERSTORMS TO DEVELOP.

&&

LAT...LON 4305 9252 4310 9232 4290 9224 4291 9262
TIME...MOT...LOC 2157Z 303DEG 24KT 4291 9246
WIND...HAIL 60MPH 1.00IN

$$

DTJ
193 
WWUS53 KARX 052212
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
512 PM CDT SAT MAY 5 2012

IAC037-067-052222-
/O.CAN.KARX.SV.W.0027.000000T0000Z-120505T2230Z/
FLOYD IA-CHICKASAW IA-
512 PM CDT SAT MAY 5 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CHICKASAW AND
SOUTHEASTERN FLOYD COUNTIES IS CANCELLED...

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

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT. CONDITIONS REMAIN
FAVORABLE FOR ADDITIONAL SEVERE THUNDERSTORMS TO DEVELOP.

LAT...LON 4305 9252 4310 9232 4290 9224 4291 9262
TIME...MOT...LOC 2212Z 303DEG 24KT 4285 9235

$$

DTJ

The office that day

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

IssuedProductOfficeCountiesLasted
May 4, 7:15 PM CDTSevere Thunderstorm WarningARXChickasaw, Floyd, Howard45 min
May 5, 3:31 PM CDTSevere Thunderstorm WarningARXFloyd, Mitchell59 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.