Alert archive / Iowa / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 15, NWS La Crosse, WI

May 3, 2012Chickasaw County, Howard County, Winneshiek County, Iowa

NWS La Crosse, WI issued this severe thunderstorm warning at May 3, 2012, 6:11 AM CDT for Chickasaw County, Howard County, Winneshiek County, Iowa. It was in force for 34 min. 1 report 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 3, 2012, 6:11 AM CDT (11:11 UTC)
Expired: May 3, 2012, 6:45 AM CDT
In force: 34 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Hail: 0.5 in
Wind: 60.0 mph

Counties Chickasaw County, IA, Howard County, IA, Winneshiek County, IA

The radar

The La Crosse radar (KARX), 102 km from the middle of the area, began a volume at 11:10 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

Time	Report	Where	Remark
May 3, 6:44 AM CDT	TSTM WND GST 60	Decorah, IA

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 11.2 hours before the alert went out and 212 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 84 J/kg
Mixed-layer CIN: -59 J/kg
Mixed-layer LCL: 1937 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

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

095 
WUUS53 KARX 031111
SVRARX
IAC037-089-191-031145-
/O.NEW.KARX.SV.W.0015.120503T1111Z-120503T1145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
611 AM CDT THU MAY 3 2012

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN CHICKASAW COUNTY IN NORTHEAST IOWA...
  HOWARD COUNTY IN NORTHEAST IOWA...
  WINNESHIEK COUNTY IN NORTHEAST IOWA...

* UNTIL 645 AM CDT

* AT 606 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SEVERE THUNDERSTORMS ROUGHLY ALONG A LINE EXTENDING FROM RICEVILLE
  TO LAWLER...MOVING NORTHEAST AT 50 MPH. THESE STORMS CAN PRODUCE   
  DAMAGING WINDS IN EXCESS OF 60 MPH. THIS WARNING                   
  EXTENDS THE PREVIOUS SEVERE THUNDERSTORM WARNING FOR               
  HOWARD...CHICKASAW AND WINNESHIEK COUNTIES.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  PROTIVIN AROUND 615 AM...
  FORT ATKINSON AND SPILLVILLE AROUND 620 AM...
  CRESCO AND CALMAR AROUND 625 AM...
  DECORAH AROUND 635 AM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4335 9255 4350 9235 4350 9162 4331 9161
      4308 9204 4308 9208 4305 9208 4294 9229
      4322 9256
TIME...MOT...LOC 1109Z 229DEG 45KT 4334 9250 4310 9212
WIND...HAIL 60MPH <.50IN

$$

JW

2 follow-up statements

340 
WWUS53 KARX 031130
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
630 AM CDT THU MAY 3 2012

IAC037-031140-
/O.CAN.KARX.SV.W.0015.000000T0000Z-120503T1145Z/
CHICKASAW IA-
630 AM CDT THU MAY 3 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CHICKASAW COUNTY
IS CANCELLED...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE 
WARNED AREA.

LAT...LON 4350 9235 4350 9162 4331 9161 4312 9196
      4319 9208 4321 9208 4321 9212 4334 9240
      4339 9248 4340 9247
TIME...MOT...LOC 1130Z 229DEG 45KT 4351 9223 4327 9185

$$

IAC089-191-031145-
/O.CON.KARX.SV.W.0015.000000T0000Z-120503T1145Z/
HOWARD IA-WINNESHIEK IA-
630 AM CDT THU MAY 3 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR WINNESHIEK AND
NORTHEASTERN HOWARD COUNTIES UNTIL 645 AM CDT...

AT 629 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WERE ROUGHLY ALONG A LINE EXTENDING FROM LIME SPRINGS
TO DECORAH...MOVING NORTHEAST AT 50 MPH. THESE STORMS CAN PRODUCE
DAMAGING WINDS IN EXCESS OF 60 MPH.

* THE SEVERE THUNDERSTORMS WILL BE NEAR...
  DECORAH AROUND 635 AM...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4350 9235 4350 9162 4331 9161 4312 9196
      4319 9208 4321 9208 4321 9212 4334 9240
      4339 9248 4340 9247
TIME...MOT...LOC 1130Z 229DEG 45KT 4351 9223 4327 9185
WIND...HAIL 60MPH <.50IN

$$

JW

018 
WWUS53 KARX 031133
SVSARX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
633 AM CDT THU MAY 3 2012

IAC089-191-031145-
/O.CON.KARX.SV.W.0015.000000T0000Z-120503T1145Z/
HOWARD IA-WINNESHIEK IA-
633 AM CDT THU MAY 3 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR WINNESHIEK AND
NORTHEASTERN HOWARD COUNTIES UNTIL 645 AM CDT...

AT 629 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WERE ROUGHLY ALONG A LINE EXTENDING FROM LIME SPRINGS
TO DECORAH...MOVING NORTHEAST AT 50 MPH. THESE STORMS CAN PRODUCE
QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH.

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 4350 9235 4350 9162 4331 9161 4312 9196
      4319 9208 4321 9208 4321 9212 4334 9240
      4339 9248 4340 9247
TIME...MOT...LOC 1134Z 229DEG 45KT 4354 9218 4330 9180
WIND...HAIL 60MPH 1.00IN

$$

JW

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 5:44 AM CDT	Severe Thunderstorm Warning	ARX	Chickasaw, Floyd, Howard, Mitchell	31 min
May 3, 6:43 AM CDT	Severe Thunderstorm Warning	ARX	Allamakee, Howard, Winneshiek	47 min
May 3, 5:24 PM CDT	Severe Thunderstorm Warning	ARX	Floyd, Mitchell	20 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2012 Every 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.