Alert archive / Iowa / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 23, NWS La Crosse, WI
NWS La Crosse, WI issued this severe thunderstorm warning at May 4, 2012, 6:20 PM CDT for Floyd County, Mitchell County, Iowa. It was in force for 55 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
- May 4, 2012, 6:20 PM CDT (23:20 UTC)
- Expired
- May 4, 2012, 7:15 PM CDT
- In force
- 55 min
- Issued by
- NWS La Crosse, WI
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 70.0 mph
Counties Floyd County, IA, Mitchell County, IA
The radar
The La Crosse radar (KARX), 150 km from the middle of the area, began a volume at 23:20 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 4, 6:42 PM CDT | TSTM WND GST 50 | Nora Springs, IA | |
| May 4, 6:48 PM CDT | TSTM WND DMG | St. Ansgar, IA | TREE DOWN COVERING THE ROAD |
| May 4, 7:02 PM CDT | HAIL 0.75 | 5 W Marble Rock, IA | |
| May 4, 7:02 PM CDT | HAIL 1 | 4 N Floyd, IA | |
| May 4, 7:02 PM CDT | HAIL 1 | 4 W Marble Rock, IA | |
| May 4, 7:14 PM CDT | TSTM WND GST 55 | Charles City, IA | RELAYED BY KCHA |
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.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| May 4, 6:01 PM CDT | Severe Thunderstorm Watch | SPC | 3 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 12:00Z, 11.3 hours before the alert went out and 196 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1101 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- -52 m²/s²
- 0-3 km storm-relative helicity
- 15 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
600
WUUS53 KARX 042320
SVRARX
IAC067-131-050015-
/O.NEW.KARX.SV.W.0023.120504T2320Z-120505T0015Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
620 PM CDT FRI MAY 4 2012
THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
FLOYD COUNTY IN NORTH CENTRAL IOWA...
MITCHELL COUNTY IN NORTH CENTRAL IOWA...
* UNTIL 715 PM CDT
* AT 612 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
SEVERE THUNDERSTORMS ROUGHLY ALONG A LINE ALONG INTERSTATE 35 FROM
ALBERT LEA TO NEAR THORTON...MOVING EAST AT 50 MPH. THESE STORMS
HAVE A HISTORY OF PRODUCING QUARTER SIZED HAIL AND DESTRUCTIVE
WINDS OF 55 TO 65 MPH OVER THE PAST HOUR.
* THE SEVERE THUNDERSTORMS WILL BE NEAR...
NORA SPRINGS AROUND 630 PM...
ST. ANSGAR AROUND 635 PM...
RUDD AND ROCKFORD AROUND 640 PM...
OSAGE AND STACYVILLE AROUND 645 PM...
CHARLES CITY AROUND 655 PM...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU ARE IN THE PATH OF THESE STORMS...PREPARE IMMEDIATELY FOR
DESTRUCTIVE WINDS...WHICH CAN UPROOT TREES... AND DOWN POWER LINES.
EVACUATE MOBILE HOMES AS THEY MAY BE OVERTURNED. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.
&&
LAT...LON 4350 9303 4350 9255 4292 9256 4290 9259
4290 9302 4304 9303
TIME...MOT...LOC 2317Z 273DEG 41KT 4343 9323 4314 9325
4283 9353
WIND...HAIL 70MPH 1.00IN
$$
BAUMGARDT3 follow-up statements
839
WWUS53 KARX 042337
SVSARX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
637 PM CDT FRI MAY 4 2012
IAC067-131-050015-
/O.CON.KARX.SV.W.0023.000000T0000Z-120505T0015Z/
MITCHELL IA-FLOYD IA-
637 PM CDT FRI MAY 4 2012
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR FLOYD AND
MITCHELL COUNTIES UNTIL 715 PM CDT...
AT 629 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WERE ROUGHLY ALONG A LINE EXTENDING FROM 10 MILES WEST
OF LYLE TO NORA SPRINGS TO 24 MILES SOUTHWEST OF ROCKFORD...MOVING
EAST AT 45 MPH. THESE STORMS PRODUCED FUNNEL CLOUDS NEAR MANLY
AROUND 630 PM AND HAVE A HISTORY OF 55 TO 65 MPH WINDS.
* THE SEVERE THUNDERSTORMS WILL BE NEAR...
ST. ANSGAR AND RUDD AROUND 645 PM...
OSAGE AROUND 650 PM...
STACYVILLE AND MARBLE ROCK AROUND 655 PM...
CHARLES CITY AROUND 700 PM...
RICEVILLE AROUND 710 PM...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU ARE IN THE PATH OF THESE STORMS...PREPARE IMMEDIATELY FOR
LARGE HAIL AND DAMAGING WINDS. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.
ALTHOUGH NOT IMMINENT...TORNADOES CAN OCCUR RAPIDLY.
&&
LAT...LON 4350 9303 4350 9255 4292 9256 4290 9259
4290 9302 4304 9303
TIME...MOT...LOC 2335Z 282DEG 39KT 4348 9306 4318 9300
4288 9328
WIND...HAIL 60MPH 1.00IN
$$
BAUMGARDT303
WWUS53 KARX 042351
SVSARX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
651 PM CDT FRI MAY 4 2012
IAC067-131-050015-
/O.CON.KARX.SV.W.0023.000000T0000Z-120505T0015Z/
MITCHELL IA-FLOYD IA-
651 PM CDT FRI MAY 4 2012
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR FLOYD AND
MITCHELL COUNTIES UNTIL 715 PM CDT...
TRAINED WEATHER SPOTTERS REPORTED WINDS OF 50 TO 55 MPH IN NORA
SPRINGS AT AROUND 645 PM. SOME FUNNELS ALONG THE LEADING EDGE OF THE
STORMS HAVE ALSO BEEN REPORTED...HOWEVER THESE HAVE NOT TOUCHED DOWN
AND NO DAMAGE HAS BEEN REPORTED.
AT 648 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WERE ROUGHLY ALONG A LINE EXTENDING FROM LYLE TO RUDD
TO 14 MILES SOUTHWEST OF MARBLE ROCK...MOVING EAST AT 40 MPH. THESE
STORMS CAN PRODUCE PENNY SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60
MPH...AND POSSIBLY FUNNELS.
* THE SEVERE THUNDERSTORMS WILL BE NEAR...
STACYVILLE AND FLOYD AROUND 655 PM...
MARBLE ROCK AROUND 700 PM...
CHARLES CITY AROUND 705 PM...
RICEVILLE AROUND 715 PM...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU ARE IN THE PATH OF THESE STORMS...PREPARE IMMEDIATELY FOR
DAMAGING WINDS AND SMALL HAIL. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.
&&
LAT...LON 4350 9303 4350 9255 4292 9256 4290 9259
4290 9302 4304 9303
TIME...MOT...LOC 2350Z 275DEG 33KT 4346 9286 4316 9280
4286 9308
WIND...HAIL 60MPH 0.75IN
$$
BAUMGARDT812
WWUS53 KARX 050007
SVSARX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
707 PM CDT FRI MAY 4 2012
IAC067-131-050015-
/O.CON.KARX.SV.W.0023.000000T0000Z-120505T0015Z/
MITCHELL IA-FLOYD IA-
707 PM CDT FRI MAY 4 2012
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR FLOYD AND
MITCHELL COUNTIES UNTIL 715 PM CDT...
LOCAL LAW ENFORCEMENT OFFICIALS REPORTED A TREE WAS DOWNED IN ST
ANSGAR...AND PEA SIZED HAIL HAS BEEN REPORTED WITH THE STORMS ACROSS
MITCHELL. ALSO...DIME SIZED HAIL WAS REPORTED 5 MILES WEST OF MARBLE
ROCK IN SOUTHWESTERN FLOYD COUNTY AT 702 PM.
AT 702 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
THUNDERSTORMS WERE ROUGHLY ALONG A LINE EXTENDING FROM STACYVILLE TO
FLOYD TO MARBLE ROCK...MOVING EAST AT 40 MPH. THESE STORMS CAN
PRODUCE PENNY SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH.
* THE SEVERE THUNDERSTORMS WILL BE NEAR...
CHARLES CITY AND RICEVILLE AROUND 710 PM...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
IF YOU ARE IN THE PATH OF THESE STORMS...PREPARE IMMEDIATELY FOR
DAMAGING WINDS AND SMALL HAIL. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.
&&
LAT...LON 4304 9302 4323 9283 4350 9301 4350 9255
4292 9256 4290 9259 4290 9303
TIME...MOT...LOC 0004Z 258DEG 34KT 4349 9268 4319 9262
4294 9289
WIND...HAIL 60MPH 0.75IN
$$
BAUMGARDTNearby
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.