Alert archive / Iowa / Tornado Warnings in 2011
Tornado Warning 31, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at Jun 20, 2011, 10:22 PM CDT for 4 counties in Iowa. It was in force for 23 min. 4 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
- Jun 20, 2011, 10:22 PM CDT (03:22 UTC)
- Expired
- Jun 20, 2011, 10:45 PM CDT
- In force
- 23 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
Counties Clay County, IA, Dickinson County, IA, O'Brien County, IA, Osceola County, IA
The radar
The Sioux Falls radar (KFSD), 112 km from the middle of the area, began a volume at 03:25 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 |
|---|---|---|---|
| Jun 20, 10:25 PM CDT | TSTM WND DMG | 4 S Hartley, IA | TWO HOG CONFINEMENTS HAD PARTIAL ROOF DAMAGE. |
| Jun 20, 10:30 PM CDT | TSTM WND DMG | 1 N Hartley, IA | PART OF A MACHINE SHED ROOF TORN OFF |
| Jun 20, 10:35 PM CDT | TSTM WND DMG | 4 S Hartley, IA | TWO HOG CONFINEMENTS HAD PARTIAL ROOF DAMAGE. |
| Jun 20, 10:45 PM CDT | TSTM WND DMG | 8 E Melvin, IA | MACHINE SHED ROOF DAMAGE ON WHITE AVE AS WELL AS TREES DOWN ON HOUSES AND ACROSS ROADS |
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 |
|---|---|---|---|
| Jun 20, 6:53 PM CDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 3.4 hours before the alert went out and 219 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
- 4194 J/kg
- Mixed-layer CIN
- -12 J/kg
- Mixed-layer LCL
- 898 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 166 m²/s²
- 0-3 km storm-relative helicity
- 182 m²/s²
- Significant tornado parameter
- 4.6
- Supercell composite
- 17.5
The text
As transmitted, in the capitals the NWS used until 2016.
605
WFUS53 KFSD 210322
TORFSD
IAC041-059-141-143-210345-
/O.NEW.KFSD.TO.W.0031.110621T0322Z-110621T0345Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1022 PM CDT MON JUN 20 2011
THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A
* TORNADO WARNING FOR...
NORTHWESTERN CLAY COUNTY IN NORTHWEST IOWA...
SOUTHWESTERN DICKINSON COUNTY IN NORTHWEST IOWA...
NORTHEASTERN O'BRIEN COUNTY IN NORTHWEST IOWA...
SOUTHEASTERN OSCEOLA COUNTY IN NORTHWEST IOWA...
* UNTIL 1045 PM CDT
* AT 1022 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS
DANGEROUS STORM WAS LOCATED 7 MILES SOUTH OF HARTLEY...OR 15 MILES
WEST OF SPENCER...AND MOVING NORTH AT 45 MPH.
* THIS TORNADIC STORM WILL BE NEAR...
HARTLEY AND EVERLY AROUND 1030 PM CDT...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.
&&
LAT...LON 4332 9557 4329 9518 4301 9535 4302 9549
4309 9566
TIME...MOT...LOC 0322Z 199DEG 38KT 4311 9543
$$
LIEBL2 follow-up statements
641 WWUS53 KFSD 210333 SVSFSD SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1033 PM CDT MON JUN 20 2011 IAC041-059-141-143-210345- /O.CON.KFSD.TO.W.0031.000000T0000Z-110621T0345Z/ OSCEOLA IA-O'BRIEN IA-DICKINSON IA-CLAY IA- 1033 PM CDT MON JUN 20 2011 ...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHWESTERN CLAY... SOUTHWESTERN DICKINSON...NORTHEASTERN O'BRIEN AND SOUTHEASTERN OSCEOLA COUNTIES UNTIL 1045 PM CDT... AT 1033 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED NEAR HARTLEY...OR 15 MILES WEST OF SPENCER...MOVING NORTH AT 50 MPH. THIS TORNADO WILL AFFECT MAINLY RURAL AREAS OF NORTHEASTERN O'BRIEN...NORTHWESTERN CLAY...SOUTHEASTERN OSCEOLA AND SOUTHWESTERN DICKINSON COUNTIES. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS. && LAT...LON 4332 9557 4329 9518 4313 9529 4321 9561 TIME...MOT...LOC 0333Z 185DEG 43KT 4325 9543 $$ LIEBL
052 WWUS53 KFSD 210348 SVSFSD SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1048 PM CDT MON JUN 20 2011 IAC041-059-141-143-210358- /O.EXP.KFSD.TO.W.0031.000000T0000Z-110621T0345Z/ OSCEOLA IA-O'BRIEN IA-DICKINSON IA-CLAY IA- 1048 PM CDT MON JUN 20 2011 ...THE TORNADO WARNING FOR NORTHWESTERN CLAY...SOUTHWESTERN DICKINSON...NORTHEASTERN O'BRIEN AND SOUTHEASTERN OSCEOLA COUNTIES HAS EXPIRED... THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED AREA. ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO WATCH REMAINS IN EFFECT UNTIL 2 AM CDT. LAT...LON 4332 9557 4329 9518 4313 9529 4321 9561 TIME...MOT...LOC 0333Z 185DEG 43KT 4325 9543 $$ LIEBL
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 9:12 PM CDT | Severe Thunderstorm Warning | FSD | Cherokee, Ida, Plymouth, Woodbury | 33 min |
| Jun 20, 9:18 PM CDT | Flash Flood Warning | FSD | Plymouth, Sioux, Woodbury | 2 hr |
| Jun 20, 9:34 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, Ida, O'Brien, Plymouth and 1 more | 41 min |
| Jun 20, 9:37 PM CDT | Tornado Warning | FSD | Plymouth | 23 min |
| Jun 20, 9:39 PM CDT | Flash Flood Warning | FSD | Lyon, Sioux | 3 hr |
| Jun 20, 10:14 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Dickinson, Lyon, O'Brien, Osceola, Sioux | 46 min |
| Jun 20, 10:20 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista | 40 min |
| Jun 20, 10:38 PM CDT | Tornado Warning | FSD | Dickinson, Osceola | 37 min |
| Jun 20, 10:46 PM CDT | Severe Thunderstorm Warning | FSD | Clay, Dickinson, Lyon, Osceola | 29 min |
| Jun 21, 12:55 AM CDT | River Flood Warning | FSD | Clay, Dickinson | 9 days |
| Jun 21, 12:55 AM CDT | River Flood Warning | FSD | Cherokee | 11 days |
| Jun 21, 12:55 AM CDT | River Flood Warning | FSD | Lyon | 5 days |
| Jun 21, 12:55 AM CDT | River Flood Warning | FSD | Clay | 6 days |
| Jun 21, 6:34 AM CDT | River Flood Warning | FSD | Lyon | 14 hr |
| Jun 21, 6:34 AM CDT | River Flood Warning | FSD | O'Brien | 30 hr |
| Jun 21, 6:34 AM CDT | River Flood Warning | FSD | Sioux | 30 hr |
Nearby
Tornado Warnings in Iowa, 2011Every tornado warning in 2011Tornadoes in 2011
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.