Alert archive / Iowa / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 101, NWS La Crosse, WI
NWS La Crosse, WI issued this severe thunderstorm warning at Sep 4, 2012, 6:09 PM CDT for Allamakee County, Clayton County, Iowa. It was in force for 36 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
- Sep 4, 2012, 6:09 PM CDT (23:09 UTC)
- Expired
- Sep 4, 2012, 6:45 PM CDT
- In force
- 36 min
- Issued by
- NWS La Crosse, WI
- Area
- Storm-based polygon
- Hail
- 1.5 in
- Wind
- 60.0 mph
Counties Allamakee County, IA, Clayton County, IA
The radar
The La Crosse radar (KARX), 78 km from the middle of the area, began a volume at 23:09 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 |
|---|---|---|---|
| Sep 4, 6:31 PM CDT | HAIL 1.75 | Marquette, IA |
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 |
|---|---|---|---|
| Sep 4, 3:27 PM CDT | Severe Thunderstorm Watch | SPC | 8 hr |
The nearest sounding before it
Davenport, (KDVN), launched 12:00Z, 11.2 hours before the alert went out and 179 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
- 1827 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 971 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 23 m²/s²
- 0-3 km storm-relative helicity
- 57 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
997
WUUS53 KARX 042309
SVRARX
IAC005-043-042345-
/O.NEW.KARX.SV.W.0101.120904T2309Z-120904T2345Z/
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
609 PM CDT TUE SEP 4 2012
THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHEASTERN ALLAMAKEE COUNTY IN NORTHEAST IOWA...
NORTH CENTRAL CLAYTON COUNTY IN NORTHEAST IOWA...
* UNTIL 645 PM CDT
* AT 604 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED NEAR SIXTEEN...OR 11 MILES NORTHWEST OF
PRAIRIE DU CHIEN...MOVING EAST AT 15 MPH. THIS STORM CAN PRODUCE
PING PONG BALL SIZE HAIL AND DAMAGING WINDS IN EXCESS OF 60 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
YELLOW RIVER STATE FOREST AROUND 620 PM...
WAUKON JCT AROUND 630 PM...
MARQUETTE AND MCGREGOR AROUND 635 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.
&&
LAT...LON 4308 9144 4321 9138 4320 9112 4316 9114
4313 9118 4302 9117
TIME...MOT...LOC 2309Z 278DEG 14KT 4312 9131
WIND...HAIL 60MPH 1.50IN
$$
AJ2 follow-up statements
591
WWUS53 KARX 042320
SVSARX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
620 PM CDT TUE SEP 4 2012
IAC005-043-042345-
/O.CON.KARX.SV.W.0101.000000T0000Z-120904T2345Z/
ALLAMAKEE IA-CLAYTON IA-
620 PM CDT TUE SEP 4 2012
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTH CENTRAL
CLAYTON AND SOUTHEASTERN ALLAMAKEE COUNTIES UNTIL 645 PM CDT...
AT 618 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM LOCATED 2 MILES SOUTHEAST OF SIXTEEN...OR 8
MILES NORTHWEST OF PRAIRIE DU CHIEN...MOVING SOUTHEAST AT 15 MPH.
THIS STORM CAN PRODUCE LARGE DAMAGING HAIL UP TO GOLF BALL SIZE AND
DAMAGING WINDS IN EXCESS OF 60 MPH.
* THE SEVERE THUNDERSTORM WILL BE NEAR...
WAUKON JCT AND ANDY MOUNTAIN CAMPGROUND AROUND 635 PM...
EFFIGY MOUNDS AROUND 640 PM...
MARQUETTE AND MCGREGOR AROUND 645 PM...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
THIS IS A DANGEROUS SITUATION. IF YOU ARE IN THE PATH OF THIS
STORM...PREPARE IMMEDIATELY FOR DESTRUCTIVE HAIL...WHICH CAN
SIGNIFICANTLY DAMAGE ROOFS...WINDOWS...SIDING AND VEHICLES. DAMAGING
WINDS ARE ALSO EXPECTED...WHICH WILL UPROOT TREES AND DOWN POWER
LINES. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM
WINDOWS.
&&
LAT...LON 4308 9140 4319 9130 4320 9112 4316 9114
4313 9118 4302 9117
TIME...MOT...LOC 2320Z 292DEG 11KT 4310 9127
WIND...HAIL 60MPH 1.75IN
$$
AJ114
WWUS53 KARX 042336
SVSARX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
636 PM CDT TUE SEP 4 2012
IAC005-043-042346-
/O.EXP.KARX.SV.W.0101.000000T0000Z-120904T2345Z/
ALLAMAKEE IA-CLAYTON IA-
636 PM CDT TUE SEP 4 2012
...THE SEVERE THUNDERSTORM WARNING FOR NORTHEAST CLAYTON AND
SOUTHEASTERN ALLAMAKEE COUNTIES IS BEING REISSUED...
PLEASE REFER TO THAT BULLETIN FOR THE LATEST SEVERE WEATHER
INFORMATION.
LAT...LON 4308 9140 4319 9130 4320 9112 4316 9114
4313 9118 4302 9117
TIME...MOT...LOC 2336Z 292DEG 11KT 4308 9121
$$
AJThe office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 4:39 AM CDT | Dense Fog Advisory | ARX | Allamakee, Chickasaw, Clayton, Fayette, Floyd, Howard and 2 more | 4 hr |
| Sep 4, 5:17 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 28 min |
| Sep 4, 6:37 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton | 38 min |
| Sep 4, 6:38 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 52 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.