Alert archive / Iowa / Tornado Warnings in 2011

Tornado Warning 3, NWS Sioux Falls, SD

April 9, 2011Ida County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Apr 9, 2011, 7:31 PM CDT for Ida County, Iowa. It was in force for 29 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: Apr 9, 2011, 7:31 PM CDT (00:31 UTC)
Expired: Apr 9, 2011, 8:00 PM CDT
In force: 29 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon

County Ida County, IA

The radar

The Omaha radar (KOAX), 124 km from the middle of the area, began a volume at 00:30 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
Apr 9, 8:02 PM CDT	TSTM WND DMG	5 Sse Ida Grove, IA	ROOF DAMAGE TO OUTBUILDING.
Apr 9, 8:02 PM CDT	TSTM WND DMG	6 S Ida Grove, IA	DAMAGE TO FARMBUILDINGS.
Apr 9, 8:05 PM CDT	TSTM WND GST 63	6 Sse Ida Grove, 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
Apr 9, 5:48 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.5 hours before the alert went out and 124 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 3327 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1533 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 270 m²/s²
0-3 km storm-relative helicity: 403 m²/s²
Significant tornado parameter: 3.7
Supercell composite: 19.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

244 
WFUS53 KFSD 100031
TORFSD
IAC093-100100-
/O.NEW.KFSD.TO.W.0003.110410T0031Z-110410T0100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
731 PM CDT SAT APR 9 2011

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN IDA COUNTY IN NORTHWEST IOWA...

* UNTIL 800 PM CDT

* AT 732 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE
  TRACKING A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS
  DANGEROUS STORM WAS LOCATED NEAR DANBURY...OR 14 MILES SOUTHWEST OF
  IDA GROVE...AND MOVING NORTHEAST AT 20 MPH.

* THIS TORNADIC STORM WILL AFFECT MAINLY RURAL AREAS OF SOUTHERN IDA
  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 4222 9568 4223 9568 4235 9535 4225 9532
      4222 9533 4220 9539 4221 9567
TIME...MOT...LOC 0032Z 237DEG 18KT 4220 9563

$$

CJ

2 follow-up statements

493 
WWUS53 KFSD 100045
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
745 PM CDT SAT APR 9 2011

IAC093-100100-
/O.CON.KFSD.TO.W.0003.000000T0000Z-110410T0100Z/
IDA IA-
745 PM CDT SAT APR 9 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHERN IDA COUNTY UNTIL
800 PM CDT...

AT 745 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 BATTLE CREEK...OR 10 MILES
SOUTHWEST OF IDA GROVE...MOVING NORTHEAST AT 20 MPH.

THIS TORNADO WILL AFFECT MAINLY RURAL AREAS OF SOUTHERN IDA 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 4222 9568 4223 9568 4235 9535 4225 9532
      4222 9533 4220 9539 4221 9567
TIME...MOT...LOC 0045Z 237DEG 18KT 4223 9556

$$

CJ

046 
WWUS53 KFSD 100052
SVSFSD

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
752 PM CDT SAT APR 9 2011

IAC093-100100-
/O.CON.KFSD.TO.W.0003.000000T0000Z-110410T0100Z/
IDA IA-
752 PM CDT SAT APR 9 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTHEASTERN IDA COUNTY
UNTIL 800 PM CDT...

AT 752 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING
A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 7 MILES SOUTHEAST OF BATTLE CREEK...OR 8 MILES
SOUTH OF IDA GROVE...MOVING NORTHEAST AT 20 MPH.

THIS TORNADO WILL AFFECT MAINLY RURAL AREAS OF SOUTHEASTERN IDA
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 4221 9552 4222 9555 4227 9557 4235 9535
      4225 9532 4222 9533 4220 9539
TIME...MOT...LOC 0052Z 245DEG 19KT 4224 9551

$$

CJ

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 9, 7:09 PM CDT	Severe Thunderstorm Warning	FSD	Ida, Woodbury	36 min
Apr 9, 7:44 PM CDT	Severe Thunderstorm Warning	FSD	Ida	31 min
Apr 9, 7:46 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, Ida, Woodbury	29 min
Apr 9, 7:56 PM CDT	Tornado Warning	FSD	Ida	34 min
Apr 9, 8:08 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Ida, Woodbury	37 min
Apr 9, 8:11 PM CDT	Severe Thunderstorm Warning	FSD	Ida	34 min
Apr 9, 8:19 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	41 min
Apr 9, 8:40 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee	35 min
Apr 9, 8:41 PM CDT	Severe Thunderstorm Warning	FSD	Ida	19 min
Apr 9, 8:49 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	41 min
Apr 9, 8:55 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	35 min
Apr 9, 9:08 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee	37 min
Apr 9, 9:09 PM CDT	Tornado Warning	FSD	Buena Vista	36 min
Apr 9, 9:15 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Sioux	30 min
Apr 9, 9:17 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth, Woodbury	43 min
Apr 9, 9:24 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, Plymouth, Woodbury	36 min
Apr 9, 9:25 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	20 min
Apr 9, 9:31 PM CDT	Tornado Warning	FSD	Plymouth, Woodbury	29 min
Apr 9, 9:36 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Clay	39 min
Apr 9, 9:46 PM CDT	Tornado Warning	FSD	Buena Vista	29 min
Apr 9, 9:48 PM CDT	Tornado Warning	FSD	Cherokee	27 min
Apr 9, 9:58 PM CDT	Severe Thunderstorm Warning	FSD	Plymouth	32 min
Apr 9, 10:02 PM CDT	Tornado Warning	FSD	Buena Vista	28 min
Apr 9, 10:09 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista	36 min
Apr 9, 10:13 PM CDT	Tornado Warning	FSD	Buena Vista, Cherokee	47 min
Apr 9, 10:24 PM CDT	Severe Thunderstorm Warning	FSD	Cherokee, O'Brien, Plymouth, Sioux	36 min
Apr 9, 10:31 PM CDT	Tornado Warning	FSD	Cherokee	29 min
Apr 9, 10:35 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Clay	30 min
Apr 9, 10:50 PM CDT	Tornado Warning	FSD	Buena Vista, Cherokee	40 min
Apr 9, 11:11 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Clay	34 min
Apr 9, 11:27 PM CDT	Tornado Warning	FSD	Buena Vista, Clay	18 min
Apr 9, 11:39 PM CDT	Tornado Warning	FSD	Clay	21 min
Apr 10, 12:24 AM CDT	Severe Thunderstorm Warning	FSD	Woodbury	36 min
Apr 10, 12:47 AM CDT	Severe Thunderstorm Warning	FSD	Cherokee, Ida	28 min

Nearby

Tornado Warnings in Iowa, 2011 Every tornado warning in 2011 Tornadoes 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.