Sioux Falls, SD

Weather Forecast Office

Damage Survey for Tornadoes in Tri-State area on October 4, 2013

Preliminary NWS Damage Survey for 10/04/2013 Tornado Event

Damage in southeast South Dakota, northeast Nebraska, and northwest Iowa

Overview…

Several tornadoes developed as low pressure moved across the Northern Plains on Friday, October 4, 2013. The following provides enhanced detail on the strongest tornadoes during this event.

Overview of the EF-4 tornado that moved across eastern Woodbury County, Iowa, done by the National Weather Service in Sioux Falls, South Dakota.

**Continuation of Macy, NE Tornado**
EF Scale Rating	EF-2
Estimated Peak Wind	130 mph
Path Length in statute miles	25
Maximum Path Width	250 yard
Fatalities	0
Injuries	2

State Date	October 4, 2013
Start Time	5:55 pm CDT
Start Location	3 miles southwest of Macy, Thurston County, Nebraska
Lat/Lon	42.087^oN 96.379^oW

End Date	October 4, 2013
End Time	6:47 pm CDT
End Location	1 mile east of Bronson, Woodbury County, Iowa
Lat/Lon	42.413^oN 96.198^oW

This EF-2 continued northeastward from Macy, NE, where the two injuries occurred. The tornado destroyed buildings two miles southeast of Salix, IA and severely damaged open-air buildings at a dairy operation three miles east of Salix. Other homes & buildings were destroyed or severely damaged by 130 mph winds approximately one and a half miles southeast of Bronson, IA, before the tornado weakened and dissipated one mile east of Bronson.

Map of Macy, NE tornado track

Click on map to download a kmz file that will display this path in Google Earth. If you download the kmz file and import it into Google Earth, each triangle will link to a description of the damage that was observed and may also include photos.

Radar images of the tornadic supercell as it moves across western Woodbury County

Radar picture from 6:20 pm CDT, October 4, 2013. The tornado has just crossed from Monona County, IA into Woodbury County, IA west of Sloan, IA.

This radar picture is from 6:32 pm CDT, October 4, 2013. The tornado is now southeast of Bronson, Iowa, where it will damage several homes and farms. At this point, the tornado is beginning to occlude, which means it is being cut off from the warm and moist air that helps maintain the tornado. Nonetheless, this tornado will remain at EF-2 strength for another 15 minutes before dissipating. A new tornado is beginning to form to the southeast and will become the Pierson, IA tornado.

Click on the radar images for a larger version of the radar picture.

Photos of tornado damage associated with the Macy, Nebraska tornado in Woodbury County

Photo of a snapped power pole 2 miles west of Sloan, Iowa along the Monona and Woodbury County line. Winds were estimated at 118 mph and the tornado was rated at EF-2 at this point.

Photo of severely damaged dairy buildings 4 miles east of Salix, Iowa. Winds were estimated at 116 mph and the tornado was rated EF-2 at this point. Photograph courtesy of Gary Brown, Emergency Manager for Woodbury County, IA.

Click on images for enlarged versions of any photo.

**Sloan, IA Tornado**
EF Scale Rating	EF-1
Estimated Peak Wind	90 mph
Path Length in statute miles	1.16
Maximum Path Width	100 yard
Fatalities	0
Injuries	0

State Date	October 4, 2013
Start Time	6:17 pm CDT
Start Location	2 miles southwest of Sloan, Woodbury County, Iowa
Lat/Lon	42.221^oN 96.263^oW

End Date	October 4, 2013
End Time	6:20 pm CDT
End Location	1 mile northwest of Sloan, Woodbury County, Iowa
Lat/Lon	42.236^oN 96.254^oW

This brief EF-1 tornado caused tree damage and minor damage to farm outbuildings before dissipating northwest of Sloan, IA.

Map of tornado path near Sloan, Iowa

Photo of tornado damage near Sloan, IA

Photo of damage to trees and some farm buildings 1.5 miles west of Sloan Iowa. The winds were estimated at 90 mph and the tornado was rated EF-1 at this point.

Click on either image for an enlarged version of the map or photo. A kmz file is also available to download into Google Earth. If you download the kmz file and import it into Google Earth, each triangle will link to a description of the damage that was observed and may also include photos. This kmz file contains information for both this Sloan, Iowa, tornado and the Macy, Nebraska tornado discussed above.

**Jackson, NE Area Tornado**
EF Scale Rating	EF-1
Estimated Peak Wind	110 mph
Path Length in statute miles	5.9
Maximum Path Width	400 yard
Fatalities	0
Injuries	0

State Date	October 4, 2013
Start Time	6:25 pm CDT
Start Location	2 miles north-northwest of Jackson, Dakota County, Nebraska
Lat/Lon	42.492^oN 96.590^oW

End Date	October 4, 2013
End Time	6:35 pm CDT
End Location	3 miles southeast of Jefferson, Union County, South Dakota
Lat/Lon	42.567^oN 96.254^oW

This tornado resulted in damage to homes and was responsible for extensive tree damage in a subdivision west of McCook Lake, which is approximately five miles south-southwest of the town of Jefferson, SD.

Map of the Jackson, NE, Jefferson, SD and rural Plymouth County tornadoes

Click on map to download a kmz file that will display this path in Google Earth. If you download the kmz file and import it into Google Earth, each triangle will link to a description of the damage that was observed and may also include photos.

Radar images of the tornadic supercell as it moves into southern Union County

Radar image from 6:24 pm CDT of the supercell producing the Jackson, NE tornado just after it has crossed the Missouri River into South Dakota. Click on the picture for a larger version of this image.

Photos of tornado damage west of McCook Lake, South Dakota

Photo of a garage destroyed and roof significantly damaged by the tornado just after it crossed the Missouri River and moved into a development 2 miles west of McCook Lake, SD. Winds were estimated at 110 mph and the tornado was rated EF-1 at this point.

Photo of a garage damaged and tree snapped at its base approximately 1 mile west-northwest of McCook Lake, SD. Winds were estimated at 100 mph and the tornado was rated EF-1 at this point.

Click on the images for enlarged versions of any photo.

**Jefferson, SD Area Tornado**
EF Scale Rating	EF-1
Estimated Peak Wind	107 mph
Path Length in statute miles	6.42
Maximum Path Width	800 yard
Fatalities	0
Injuries	0

State Date	October 4, 2013
Start Time	6:35 pm CDT
Start Location	2.5 miles south of Jefferson, Union County, South Dakota
Lat/Lon	42.570^oN 96.555^oW

End Date	October 4, 2013
End Time	6:45 pm CDT
End Location	5 miles northeast of Jefferson, Union County, South Dakota
Lat/Lon	42.656^oN 96.505^oW

This tornado resulted in damage to farm outbuildings and homes, while also causing widespread tree and crop damage. Buildings at a cattle operation were also damaged along Interstate 29, approximately two miles south of Jefferson, SD before the tornado crossed the Interstate.

Radar images of the tornadic supercell as it moves across southern Union County

Radar image from 6:37 pm CDT of the tornado-producing supercell near Jefferson, SD.

Click on the image for a larger version.

Photos of tornado damage east of Jefferson, South Dakota

Photo of damage to farm buidings 1 mile southeast of Jefferson, South Dakota. In addition to the building damage, numerous trees and branches were brought down and corn was flattened in fields to the northeast of this farmstead. Winds were estimated at 107 mph and the tornado was rated EF-1 at this point.

Photo of a grainbin which was blown into the side of a house approximately 2 miles northeast of Jefferson, South Dakota, near the Iowa border. In addition, numerous large branches were down. Winds were estimated around 90 mph and the tornado was rated EF-1 at this point.

Click on the photos for a larger version.

**Rural Plymouth County, IA Tornado**
EF Scale Rating	EF-1
Estimated Peak Wind	105 mph
Path Length in statute miles	1.12
Maximum Path Width	100 yard
Fatalities	0
Injuries	0

State Date	October 4, 2013
Start Time	6:50 pm CDT
Start Location	8 miles northeast of Jefferson, Union County, South Dakota
Lat/Lon	42.676^oN 96.445^oW

End Date	October 4, 2013
End Time	6:52 pm CDT
End Location	8 miles northwest of Hinton, Plymouth County, Iowa
Lat/Lon	42.688^oN 96.432^oW

This brief EF-1 tornado caused damage to farm buildings and trees in the grove surrounding the farmstead.

Radar images of the tornadic supercell over southwestern Plymouth County

Radar image of tornadic supercell from 6:50 pm CDT, October 4, 2013.

Radar image of the tornadic supercell in southwestern Plymouth County, IA at 6:50 pm CDT.

Click on the image for a larger version of this image.

Photo of tornado damage in southwestern Plymouth County, Iowa

Photo of damage to farm in southwestern Plymouth County, Iowa.

This is a photo of damage to a farm in southwestern Plymouth County - approximately 8 miles northwest of Hinton, Iowa. Numerous trees were snapped approximately 4-6 feet above the ground. There was also damage to some outbuildings, and a tree falling on the house caused damage to the roof.

Click on the photo for a larger version.

**Alta, IA tornado**
EF Scale Rating	EF-1
Estimated Peak Wind	100 mph
Path Length in statute miles	5.45
Maximum Path Width	200 yards
Fatalities	0
Injuries	0

State Date	October 4, 2013
Start Time	8:32 pm CDT
Start Location	5 miles south-southwest of Alta, Buena Vista County, Iowa
Lat/Lon	42.603^oN 95.365^oW

End Date	October 4, 2013
End Time	8:42 pm CDT
End Location	Alta, Buena Vista County, Iowa
Lat/Lon	42.664^oN 95.297^oW

This EF-1 tornado initially caused extensive crop and tree damage, before intensifying and causing more significant damage to a drive-through garage and other outbuildings at a farmstead five miles southwest of Alta. The tornado then proceeded northeast, causing damage to a couple of farmsteads as it reached a maximum width of 200 yards a couple of miles south of Alta. As the tornado was beginning to weaken, it moved towards the southern outskirts of Alta. At this point, it still managed to damage the roof of the school and produced quite a bit of damage to the baseball complex. Shortly thereafter, the tornado dissipated before it would have entered the town of Alta. The parent storm caused additional damage to trees in Alta.

Maps of the Alta, IA tornado tracks

Click on map to download a kmz file that will display this path in Google Earth. If you download the kmz file and import it into Google Earth, each triangle will link to a description of the damage that was observed and may also include photos.

Radar images of the tornadic supercell near Alta, Iowa

This is a radar image of the tornadic storm near Alta Iowa at 8:37 pm CDT. Unlike the other storms shown above, this storm does not have a hook echo associated with it.

Click on the image for a larger version of this image.

Photos of tornado damage near Alta, Iowa

This is a photo of a destroyed garage. The damage occurred 5 miles southwest of Alta, Iowa. As the garage gave way, portions of the roof also lifted over the portion of the house adjacent to the garage. Several large branches and a couple of trees were down in the area as well. The winds were estimated around 100 mph and the tornado was rated EF-1 at this point.

This is a photo of bleachers from a nearby baseball complex that were thrown into trees to the north of the baseball diamond. The bleachers were thrown over 100 yards. In addition to this damage, there was also damage to the roof of the Alta High School and numerous trees were damaged in the vicinity. The winds were estimated around 80 mph and the tornado was rated EF-0 at this point.

Click on the photos for a larger version.

EF Scale: The Enhanced Fujita tornado scale classifies tornadoes into the following categories:

EF0...wind speeds 65 to 85 mph.
EF1...wind speeds 86 to 110 mph.
EF2...wind speeds 111 to 135 mph.
EF3...wind speeds 136 to 165 mph.
EF4...wind speeds 166 to 200 mph.
EF5...wind speeds greater than 200 mph.

Note: Information in this statement is preliminary and subject to change pending final review of the event and publication in NWS Storm Data.