National Weather Service United States Department of Commerce

During the evening of April 9, 2011, several tornadoes formed across northwestern Iowa, doing damage to some towns as well as farms and homes in rural areas.  A supercell that formed in northeast Nebraska produced multiple tornadoes from Monona County, Iowa, into Pocahontas County, Iowa.  One of the tornadoes touched down west of Arthur, Iowa, in Ida County.  This tornado had a path length of approximately 3 to 4 miles and was on the ground for 5 to 10 minutes.  The tornado touched down west of Arthur around 8:20 pm CDT. The tornado crossed Highway 175 about 2 miles west of Arthur before turning to the northeast and lifting approximately 2 miles northwest of Arthur.  This tornado was rated EF2.

A second supercell formed in Plymouth County and moved across Cherokee County.  A tornado formed near Highway 59 approximately 8 miles south of Cherokee, IA aorund 9:20 pm CDT.  The tornado had a path length of approximately 5 miles and was on the ground around 10 minutes.  This tornado moved northeast across rural portions of southern Cherokee County, doing damage to power lines and two farmsteads.  The tornado lifted when it was approximately 7 miles south of Aurelia.  This tornado was rated EF1.

A kmz file has been created which can be opened in Google Earth to look at the damage path of the tornadoes.  Click the preceding link to download the file.

Below is a map showing the path of the tornado near Arthur, Iowa.

Map of tornado track near Arthur, Iowa

A - Tornado rating: EF1

The tornado crossed Highway 175 causing some power poles to lean due to the strong winds.


B - Tornado rating: EF2

Below is a photo of the tornado near this time.  Photo is courtesy of Jodi Irvin.

Photo of Arthur tornado.  Image provided by Jodi Irvin.
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There was damage to several buildings and trees by a farmstead.  There was also a power pole snapped at the base and several other power poles were leaned over by the tornado.

 

A picture of the damage to outbuildings to this farmstead.  Two grain bins were destroyed, one outbuilding severely damaged and at least another outbuilding that was destroyed by the tornado.
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A picture of the damage to outbuildings to this farmstead. Two grain bins were destroyed, one outbuilding severely damaged and at least another outbuilding that was destroyed by the tornado.

A picture of the farm from the opposite side.  Debris from the buildings can be seen interspersed amongst the farm equipment.  Two snapped trees can be seen on the right side of the photo.
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A picture of the farm from the opposite side. Debris from the buildings can be seen interspersed amongst the farm equipment. Two snapped trees can be seen on the right side of the photo.

Photo of snapped power pole near the farmstead.
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Snapped power pole near the farmstead.

Several large trees are down in the yard.  Also numerous shingles were taken off of the house in the foreground as well as off the garage in the background.
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Several large trees are down in the yard. Also numerous shingles were taken off of the house in the foreground as well as off the garage in the background.

C - Debris from the farmstead to the southwest was scattered across this field by the tornado.

D - The tornado crossed the road here.  The tornado was approximately 1/4 mile wide at this point.

E - The tornado crossed this road.  The tornado had begun to weaken at this point and was much narrower than it had been a mile to the south.

 


Below is a map showing the path of a second tornado, this one located south of Galva, Iowa.

Map of tornado south of Galva, Iowa.

A - Tornado rating:  EF1

A farmstead was severely damaged at this location. The roof was taken off of a house with numerous outbuildings destroyed.

 

The roof was taken off of this house.  A portion of the roof can be seen on the left side of the photo.  One tree is also uprooted and there is tin from another building lodged in a tree on the right side of the photo.
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The roof was taken off of this house. A portion of the roof can be seen on the left side of the photo. One tree is also uprooted and there is tin from another building lodged in a tree on the right side of the photo.

Debris from the home and buildings scattered in a shelter belt near the home.
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Debris from the home and buildings scattered in a shelter belt near the home.

 


B - Tornado rating - EF1

An outbuilding seen in the image below had part of its roof taken off. There was also other minor damage on the farmstead.

Half of the roof is removed from an outbuilding.
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C - Tornado rating - EF1

Five power poles were snapped by the tornado at this location.

D - An outbuilding at the ethanol plant was damaged.


Below is a map showing the path of the tornado south of Cherokee, Iowa.

 The path of the tornado south of Cherokee, Iowa.

 Red area on map is where power poles were snapped by the tornado.


A - Tornado rating:  EF1

A power pole was snapped at the base and two or three other powers poles were leaning.

Powerpoles
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B - Tornado rating - EF1

The tornado moved across the empty field and then crossed R Ave. and moved across a farmstead.  Several outbuildings were damaged or destroyed by the tornado as it moved through the property and into the field.  Several trees were knocked down or damaged by the tornado and a home took damage with several windows blown out by the tornado.

 

Confinement buidlings damaged
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Portions of this confinement area were damaged as winds caused the roof to be lifted and some of the buildings collapsed.  In the foreground, wires hang loosely from an electrical pole.

Empty tank toppled to ground
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An empty tank was tipped by the tornadic winds.  The tank was anchored to a cement pad by a 6 inch bolt in cement.  Note that the full tank remained upright and the bulding behind the tank had no damage to the roof.  The east (right) end of the building did have damage.

Camper tipped over by tornado
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A camper was tipped over with the back end of the camper blown into the garage.

Damage to garage
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The east side of the house had a piece of debris embedded about 5 feet above the ground.  There was also minor damage to the roof.  Note the amount of mud and grass stuck to the east side of the house due to the east winds from the tornado as it passed to the south.  Several windows of this home were broken out on the south and east side.

Aerial photo of tornado track near farm.
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An aerial view of the tornado track near the farm.  A faint scouring of corn stubble can be seen on the right (west) side of the photo as the tornado approached the road.  To the left (east) of the farm notice that the scouring is much more evident and also appears to wider - a likely indication that the tornado was strengthening as it moved east of the farmstead.  Photo is courtesy of  Ben Shuberg, Emergency Manager of Cherokee County, Iowa.


C - Tornado rating:  EF1

One confinement bulding was destroyed as the tornado passed to the south of this area.  A second confinement building had damage to the roof.  Debris from the confinement building was blown to the southeast.  One-quarter mile south, two outbuildings were damaged and a pine tree was snapped 15 feet above the ground.  The top of the tree was blown to the east-northeast.  As the tornado crossed S Ave., the tornado appeared to widen to at least 300 yards.

 

Destroyed confinement building
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A destroyed confinement building with debris blown to the south and southeast.  In the background are the power poles.  Across the street (east) from this building, all the power poles similar to this one pictured were snapped off at the base.  Approximately 1-1/2 miles of power poles were snapped (denoted by the red area on the map above).

Pine tree snapped above base by tornadic winds
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A pine tree snapped approximately 15 feet above the ground.  The top of the tree can be seen in the foreground and landed east northeast of the tree.

Aerial photo of damage to confinement
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An aerial view of the damage to the confinement building.  To the east (left) of the confinement building , spiral scouring marks can be seen denoting the path of the tornado.  Photo is courtesy of  Ben Shuberg, Emergency Manager of Cherokee County, Iowa.


D - Three empty grain bins were destroyed by the northwest winds flowing into the tornado. As one grain bin came loose, it damaged a semi-trailer. Four pine trees were also broken off 6 to 10 feet above the ground. Debris from the grain bins was blown southeast toward the tornado which was approximately a quarter mile away.

 

Tipped semi-trailer, damaged grain bin, and cement pad for grain bin.
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The tops of three of the pine trees that were snapped can be seen as well as the semi-trailer which was tipped into the grain bin. Behind the pine tree is the cement pad that had been the location where a grain bin had been anchored. As this grain bin was blown off the cement pad, some of the metal struck a second semi-trailer truck, damaging the cab. This semi truck can be seen on the left (south) side of the picture.

Broken pole and debris from grain bin.
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The remains of a power pole can be seen in the foreground with the pole pointing to the southeast. Debris from a grain bin can be seen behind the pole.  In the background, to the left (east) of the upright grain bin, the top of a 4th pine tree can be seen. This portion of the tree was carried over 50 yards from where it stood to its landing place.


E - Winds of 60 to 80 mph blew down 3 to 5 trees and also caused several large branches to break off.

F - Tornado rating: EF0

The tornado crossed County Highway M21. The tornado was less than 100 yards wide at this point. The power poles on the side of the road were not damaged by the tornado and the only evidence of the tornado was some scouring of the ground by the tornado.