Alert archive / Iowa / Severe Thunderstorm Warnings in 2012
Severe Thunderstorm Warning 113, NWS La Crosse, WI
NWS La Crosse, WI issued this severe thunderstorm warning at Sep 4, 2012, 10:42 PM CDT for Allamakee County, Winneshiek County, Iowa. It was in force for 33 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, 10:42 PM CDT (03:42 UTC)
- Expired
- Sep 4, 2012, 11:15 PM CDT
- In force
- 33 min
- Issued by
- NWS La Crosse, WI
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 50.0 mph
Counties Allamakee County, IA, Winneshiek County, IA
The radar
The La Crosse radar (KARX), 87 km from the middle of the area, began a volume at 03:43 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, 10:42 PM CDT | HAIL 1 | 3 Ese Calmar, 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 00:00Z, 3.7 hours before the alert went out and 198 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
- 1890 J/kg
- Mixed-layer CIN
- -49 J/kg
- Mixed-layer LCL
- 1662 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- -23 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- -0.0
- Supercell composite
- -0.9
The text
As transmitted, in the capitals the NWS used until 2016.
138 WUUS53 KARX 050342 SVRARX IAC005-191-050415- /O.NEW.KARX.SV.W.0113.120905T0342Z-120905T0415Z/ BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE LA CROSSE WI 1042 PM CDT TUE SEP 4 2012 THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHWESTERN ALLAMAKEE COUNTY IN NORTHEAST IOWA... SOUTHEASTERN WINNESHIEK COUNTY IN NORTHEAST IOWA... * UNTIL 1115 PM CDT * AT 1038 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM LOCATED NEAR OSSIAN...OR 11 MILES SOUTH OF DECORAH...MOVING EAST AT 25 MPH. THIS STORM CAN PRODUCE QUARTER SIZE HAIL. * THE SEVERE THUNDERSTORM WILL BE NEAR... CASTALIA AND FRANKVILLE AROUND 1050 PM... STATE ROAD 51 AND COUNTY W 48 AROUND 1100 PM... POSTVILLE AROUND 1105 PM... COUNTY ROADS X 16 AND B 38 AROUND 1110 PM... PRECAUTIONARY/PREPAREDNESS ACTIONS... IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE HAIL. 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 4309 9193 4326 9189 4322 9145 4308 9149 TIME...MOT...LOC 0341Z 289DEG 21KT 4314 9174 WIND...HAIL <50MPH 1.00IN $$ JW
2 follow-up statements
656 WWUS53 KARX 050351 SVSARX SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1051 PM CDT TUE SEP 4 2012 IAC005-191-050415- /O.CON.KARX.SV.W.0113.000000T0000Z-120905T0415Z/ ALLAMAKEE IA-WINNESHIEK IA- 1051 PM CDT TUE SEP 4 2012 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTHEASTERN WINNESHIEK AND SOUTHWESTERN ALLAMAKEE COUNTIES UNTIL 1115 PM CDT... TRAINED WEATHER SPOTTERS REPORTED PING PONG BALL SIZE HAIL IN CALMAR WITH A SEVERE THUNDERSTORM. AT 1047 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE SEVERE THUNDERSTORM WAS LOCATED NEAR OSSIAN...OR 10 MILES SOUTH OF DECORAH...MOVING EAST AT 10 MPH. THIS STORM CAN PRODUCE PING PONG BALL SIZE HAIL. THIS STORM IS ALSO CAPABLE OF PRODUCING LARGE QUANTITIES OF HAIL THAT MAY COVER ROADWAYS. * THE SEVERE THUNDERSTORM WILL BE NEAR... OSSIAN AROUND 1055 PM... COUNTY ROAD W 46 AND CENTENNIAL ROAD AROUND 1110 PM... POSTVILLE AND FRANKVILLE AROUND 1115 PM... PRECAUTIONARY/PREPAREDNESS ACTIONS... IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR LARGE HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS. TORRENTIAL RAINFALL FROM THESE STORMS MAY ALSO CAUSE THE PONDING OF WATER ON ROADWAYS AND LOCALIZED FLOODING. && LAT...LON 4309 9193 4326 9189 4322 9145 4308 9149 TIME...MOT...LOC 0350Z 270DEG 10KT 4316 9179 WIND...HAIL <50MPH 1.50IN $$ JW
999 WWUS53 KARX 050418 SVSARX SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE LA CROSSE WI 1118 PM CDT TUE SEP 4 2012 IAC005-191-050427- /O.EXP.KARX.SV.W.0113.000000T0000Z-120905T0415Z/ ALLAMAKEE IA-WINNESHIEK IA- 1118 PM CDT TUE SEP 4 2012 ...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WINNESHIEK AND SOUTHWESTERN ALLAMAKEE COUNTIES HAS EXPIRED... THE STORM IS STILL PRODUCING VERY HEAVY RAINFALL IN ADDITION TO SMALL HAIL. ADDITIONAL SEVERE THUNDERSTORMS ARE POSSIBLE LATE TONIGHT INTO EARLY WEDNESDAY MORNING. A FLASH FLOOD WARNING REMAINS IN EFFECT. LAT...LON 4309 9193 4326 9189 4322 9145 4308 9149 TIME...MOT...LOC 0351Z 270DEG 10KT 4316 9179 $$ JW
The office that day
Everything else NWS La Crosse, WI issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 7:06 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 24 min |
| Sep 4, 7:35 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 70 min |
| Sep 4, 8:09 PM CDT | Flash Flood Warning | ARX | Allamakee, Clayton | 6 hr |
| Sep 4, 10:10 PM CDT | Severe Thunderstorm Warning | ARX | Clayton, Fayette | 65 min |
| Sep 4, 11:09 PM CDT | Flash Flood Warning | ARX | Allamakee, Winneshiek | 5 hr |
| Sep 4, 11:14 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 46 min |
| Sep 4, 11:36 PM CDT | Severe Thunderstorm Warning | ARX | Allamakee, Clayton, Fayette, Winneshiek | 47 min |
| Sep 4, 11:59 PM CDT | Severe Thunderstorm Warning | ARX | Clayton | 61 min |
| Sep 5, 12:12 AM CDT | Severe Thunderstorm Warning | ARX | Floyd, Mitchell | 63 min |
| Sep 5, 12:31 AM CDT | Severe Thunderstorm Warning | ARX | Chickasaw, Howard | 44 min |
| Sep 5, 1:06 AM CDT | Severe Thunderstorm Warning | ARX | Fayette, Winneshiek | 24 min |
| Sep 5, 1:28 AM CDT | Severe Thunderstorm Warning | ARX | Allamakee | 32 min |
| Sep 5, 1:51 AM CDT | Flash Flood Warning | ARX | Clayton, Fayette | 3 hr |
| Sep 5, 1:59 AM CDT | Flash Flood Warning | ARX | Allamakee, Clayton | 3 hr |
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.