Alert archive / Iowa / Tornado Warnings in 2012
Tornado Warning 16, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at May 1, 2012, 9:44 PM CDT for Clay County, Iowa. It was in force for 31 min. 3 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 1, 2012, 9:44 PM CDT (02:44 UTC)
- Expired
- May 1, 2012, 10:15 PM CDT
- In force
- 31 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
County Clay County, IA
The radar
The Sioux Falls radar (KFSD), 131 km from the middle of the area, began a volume at 02:44 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 1, 9:55 PM CDT | TSTM WND GST 65 | Se Spencer, IA | NUMEROUS TREES DOWN AND SOME WINDOWS BLOWN OUT OF BUILDINGS. |
| May 1, 9:56 PM CDT | TSTM WND GST 60 | 3 N Royal, IA | |
| May 1, 10:06 PM CDT | TSTM WND GST 71 | Spencer, IA | MEASURED BY RWIS. |
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 1, 9:18 PM CDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 2.7 hours before the alert went out and 227 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
- 1502 J/kg
- Mixed-layer CIN
- -30 J/kg
- Mixed-layer LCL
- 1477 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 122 m²/s²
- Significant tornado parameter
- 0.4
- Supercell composite
- 5.2
The text
As transmitted, in the capitals the NWS used until 2016.
625 WFUS53 KFSD 020244 TORFSD IAC041-020315- /O.NEW.KFSD.TO.W.0016.120502T0244Z-120502T0315Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE SIOUX FALLS SD 944 PM CDT TUE MAY 1 2012 THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A * TORNADO WARNING FOR... NORTHWESTERN CLAY COUNTY IN NORTHWEST IOWA... * UNTIL 1015 PM CDT * AT 944 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED NEAR EVERLY...OR 11 MILES WEST OF SPENCER...AND MOVING NORTHEAST AT 40 MPH. * THIS TORNADIC STORM WILL BE NEAR... SPENCER AROUND 955 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 4325 9513 4312 9508 4308 9535 4316 9539 TIME...MOT...LOC 0244Z 246DEG 35KT 4314 9530 $$ CJ
2 follow-up statements
346 WWUS53 KFSD 020253 SVSFSD SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 953 PM CDT TUE MAY 1 2012 IAC041-020315- /O.CON.KFSD.TO.W.0016.000000T0000Z-120502T0315Z/ CLAY IA- 953 PM CDT TUE MAY 1 2012 ...A TORNADO WARNING REMAINS IN EFFECT FOR NORTH CENTRAL CLAY COUNTY UNTIL 1015 PM CDT... AT 953 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED NEAR EVERLY...OR 5 MILES WEST OF SPENCER...MOVING NORTHEAST AT 40 MPH. THIS TORNADO WILL AFFECT MAINLY RURAL AREAS OF NORTH CENTRAL CLAY COUNTY. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS. && LAT...LON 4325 9513 4316 9510 4313 9524 4317 9528 TIME...MOT...LOC 0253Z 246DEG 35KT 4316 9519 $$ CJ
901 WWUS53 KFSD 020308 SVSFSD SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SIOUX FALLS SD 1008 PM CDT TUE MAY 1 2012 IAC041-020318- /O.EXP.KFSD.TO.W.0016.000000T0000Z-120502T0315Z/ CLAY IA- 1008 PM CDT TUE MAY 1 2012 ...THE TORNADO WARNING FOR NORTH CENTRAL CLAY COUNTY WILL EXPIRE AT 1015 PM CDT... THE TORNADO THREAT HAS DIMINISHED...THEREFORE THE TORNADO WARNING HAS EXPIRED. HOWEVER...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR THE AREA. LAT...LON 4325 9513 4316 9510 4313 9524 4317 9528 TIME...MOT...LOC 0308Z 246DEG 35KT 4321 9500 $$ CJ
The office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 1, 7:12 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 33 min |
| May 1, 7:27 PM CDT | Tornado Warning | FSD | Lyon, Sioux | 33 min |
| May 1, 7:41 PM CDT | Severe Thunderstorm Warning | FSD | Lyon, Sioux | 34 min |
| May 1, 7:57 PM CDT | Tornado Warning | FSD | Lyon | 33 min |
| May 1, 8:09 PM CDT | Severe Thunderstorm Warning | FSD | Lyon | 36 min |
| May 1, 8:40 PM CDT | Flash Flood Warning | FSD | Lyon | 3 hr |
| May 1, 9:15 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, O'Brien, Plymouth, Sioux | 30 min |
| May 1, 9:22 PM CDT | Severe Thunderstorm Warning | FSD | Dickinson, Osceola | 38 min |
| May 1, 9:29 PM CDT | Tornado Warning | FSD | Clay, O'Brien | 46 min |
| May 1, 9:41 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, Dickinson, O'Brien, Osceola | 34 min |
| May 1, 10:13 PM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Clay, Dickinson | 17 min |
Nearby
Tornado Warnings in Iowa, 2012Every tornado warning in 2012Tornadoes 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.