Alert archive / Iowa / Tornado Warnings in 2011
Tornado Warning 42, NWS Sioux Falls, SD
NWS Sioux Falls, SD issued this tornado warning at Sep 2, 2011, 3:09 AM CDT for Cherokee County, Plymouth County, Iowa. It was in force for 24 min. 2 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
- Sep 2, 2011, 3:09 AM CDT (08:09 UTC)
- Expired
- Sep 2, 2011, 3:33 AM CDT
- In force
- 24 min
- Issued by
- NWS Sioux Falls, SD
- Area
- Storm-based polygon
Counties Cherokee County, IA, Plymouth County, IA
The radar
The Sioux Falls radar (KFSD), 122 km from the middle of the area, began a volume at 08:12 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 2, 3:18 AM CDT | TSTM WND GST 60 | Wnw Marcus, IA | SEVERAL SMALL BRANCHES DOWN. WINDS WERE ACCOMPANIED BY QUARTER SIZE HAIL. |
| Sep 2, 3:18 AM CDT | HAIL 1 | Wnw Marcus, IA | VERY FEW HAILSTONES BUT THEY WERE AT LEAST QUARTER SIZE. HAIL WAS ACCOMPANIED BY DAMAGING WINDS. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Omaha, NE (KOAX), launched 00:00Z, 8.2 hours before the alert went out and 174 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
- 3493 J/kg
- Mixed-layer CIN
- -228 J/kg
- Mixed-layer LCL
- 1967 m above ground
- 0-6 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 118 m²/s²
- 0-3 km storm-relative helicity
- 157 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.7
The text
As transmitted, in the capitals the NWS used until 2016.
334
WFUS53 KFSD 020809
TORFSD
IAC035-149-020845-
/O.NEW.KFSD.TO.W.0042.110902T0809Z-110902T0845Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
309 AM CDT FRI SEP 2 2011
THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A
* TORNADO WARNING FOR...
NORTHERN CHEROKEE COUNTY IN NORTHWEST IOWA...
EAST CENTRAL PLYMOUTH COUNTY IN NORTHWEST IOWA...
* UNTIL 345 AM CDT
* AT 309 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS
DANGEROUS STORM WAS LOCATED 5 MILES SOUTHEAST OF REMSEN...OR 13
MILES EAST OF LE MARS...AND MOVING NORTHEAST AT 40 MPH.
* THIS TORNADIC STORM WILL BE NEAR...
MARCUS AROUND 320 AM CDT...
CLEGHORN AROUND 325 AM CDT...
CHEROKEE AROUND 335 AM CDT...
OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
MERIDEN.
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 4274 9549 4269 9592 4279 9597 4291 9565
4291 9559
TIME...MOT...LOC 0809Z 244DEG 34KT 4275 9591
$$
CJ2 follow-up statements
289
WWUS53 KFSD 020820
SVSFSD
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
320 AM CDT FRI SEP 2 2011
IAC149-020830-
/O.CAN.KFSD.TO.W.0042.000000T0000Z-110902T0845Z/
PLYMOUTH IA-
320 AM CDT FRI SEP 2 2011
...THE TORNADO WARNING FOR EAST CENTRAL PLYMOUTH COUNTY IS
CANCELLED...
THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.
LAT...LON 4271 9582 4277 9586 4283 9586 4291 9565
4291 9559 4274 9549
TIME...MOT...LOC 0820Z 243DEG 33KT 4280 9573
$$
IAC035-020845-
/O.CON.KFSD.TO.W.0042.000000T0000Z-110902T0845Z/
CHEROKEE IA-
320 AM CDT FRI SEP 2 2011
...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHERN CHEROKEE COUNTY
UNTIL 345 AM CDT...
AT 320 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
STORM WAS LOCATED NEAR MARCUS...OR 20 MILES EAST OF LE MARS...MOVING
NORTHEAST AT 40 MPH.
THIS DANGEROUS STORM WILL BE NEAR...
CLEGHORN AROUND 325 AM CDT...
CHEROKEE AROUND 330 AM CDT...
OTHER LOCATIONS IMPACTED BY THIS TORNADO INCLUDE MERIDEN.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TORNADOES ARE DIFFICULT TO SEE AT NIGHT. TAKE COVER NOW.
&&
LAT...LON 4271 9582 4277 9586 4283 9586 4291 9565
4291 9559 4274 9549
TIME...MOT...LOC 0820Z 243DEG 33KT 4280 9573
$$
CJ547
WWUS53 KFSD 020833
SVSFSD
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
333 AM CDT FRI SEP 2 2011
IAC035-020843-
/O.CAN.KFSD.TO.W.0042.000000T0000Z-110902T0845Z/
CHEROKEE IA-
333 AM CDT FRI SEP 2 2011
...THE TORNADO WARNING FOR NORTHERN CHEROKEE COUNTY IS CANCELLED...
THE TORNADO THREAT HAS DIMINISHED...THEREFORE THE TORNADO WARNING HAS
BEEN CANCELLED. HOWEVER...A SEVERE THUNDERSTORM WARNING REMAINS IN
EFFECT FOR THE AREA.
LAT...LON 4271 9582 4277 9586 4283 9586 4291 9565
4291 9559 4274 9549
TIME...MOT...LOC 0833Z 243DEG 33KT 4285 9558
$$
CJThe office that day
Everything else NWS Sioux Falls, SD issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 2, 2:33 AM CDT | Severe Thunderstorm Warning | FSD | Plymouth, Sioux | 27 min |
| Sep 2, 2:56 AM CDT | Severe Thunderstorm Warning | FSD | Cherokee, O'Brien, Plymouth, Sioux | 34 min |
| Sep 2, 3:27 AM CDT | Severe Thunderstorm Warning | FSD | Buena Vista, Cherokee, Clay, O'Brien | 33 min |
| Sep 2, 3:40 AM CDT | Severe Thunderstorm Warning | FSD | Clay, O'Brien | 35 min |
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.