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Sioux Falls, SD

Weather Forecast Office

August 17th Severe Thunderstorms and Tornadoes

Weather.gov > Sioux Falls, SD > August 17th Severe Thunderstorms and Tornadoes

Overview

Severe thunderstorms formed across central South Dakota during the late afternoon. As these storms moved across southeastern South Dakota, they formed into a squall line and produced large hail and damaging winds.  As the storms moved east of I-29, several tornadoes were produced by the storms. One EF-1 tornado went through Hadley, Minnesota and a second EF-1 tornado moved west and south of Rock Rapids, Iowa. Five EF-0 tornadoes also touched down in Nobles, Murray, and Cottonwood Counties in Minnesota.  These tornadoes primarily did damage to crops and trees although a few homes and farm buildings were damaged.  In addition, winds up to 90 mph moved through Okoboji Iowa causing tree damage as well as damage to a few homes and an office building.

 Supercell which produced 2 inch hail near Lake Andes.
Supercell which produced 2 inch hail near Lake Andes, SD.
(Julie Weddell)
Map of Warnings Issued Rainfall map Radar Velocity Loop
Summary of Warnings Issued Map of 24-hour Rainfall Shelf Cloud near Mitchell, SD

Tornadoes:

Tornado - Hadley, Minnesota
Murray County

Date August 17, 2019
Time (Local) 10:54 - 11:01 PM CDT
EF Rating EF-1
Est. Peak Winds 105 mph
Path Length 3.94 miles
Max Width 75 yards
Injuries/Deaths 0 injuries and deaths

Summary:  

The tornado touched down southwest of 
Hadley, Minnesota and reached the town
around 10:57 PM CDT. The tornado had a 
width of around 75 yards as it moved 
through the town, lifting to the 
northeast. While a few buildings had 
damage, most of the damage was to trees.

No injuries or deaths were reported.

 

Track Map

Track Map EF-Scale

Downloadable KMZ File

Tornado - Rock Rapids, Iowa
Lyon County

Date August 17, 2019
Time (Local) 10:34 - 10:43 PM CDT
EF Rating EF-1
Est. Peak Winds 105
Path Length 6.92 miles
Max Width 75 yds
Injuries/Deaths 0 injuries or death

Summary:

The tornado touched down west of Rock 
Rapids, IA and moved south of town 
before lifting southeast of town. At 
peak width, the tornado had a width of 
75 yards. Outbuildings to four farmsteads 
were damaged west and south of Rock Rapids.
Additional tree damage was observed south 
and southeast of Rock Rapids.

Track Map

Track Map EF-Scale

Downloadable KMZ File

 

Tornado - Reading, MInnesota
Nobles County

Date August 17, 2019
Time (Local) 10:59 - 11:03 PM CDT
EF Rating EF-0
Est. Peak Winds 80 mph
Path Length 4.01 miles
Max Width 50 yds
Injuries/Deaths 0 injuries or death

Summary:

The tornado touched down northwest of Reading, 
Minnesota.  It primarily did damage to trees and 
crops north of Reading.  One home had damage
tts roof from the tornado.

Track Map

Track Map EF-Scale

Downloadable KMZ File

 

Tornado - Iona, MInnesota
Murray County

Date August 17, 2019
Time (Local) 10:59 - 11:01 PM CDT
EF Rating EF-0
Est. Peak Winds 85 mph
Path Length 0.79 miles
Max Width 50 yds
Injuries/Deaths 0 injuries or death

Summary:

The tornado touched south of Iona flattening corn in 
the area.  As the tornado moved northeast, it hit a 
cemetery toppling some headstones and snapping 
a few trees.  The tornado lifted as it moved northeast
of the cemetery.

Track Map

Track Map EF-Scale

Downloadable KMZ File

 

Tornado - Rural Murray County
Murray County

Date August 17, 2019
Time (Local) 11:08 - 11:10 PM CDT
EF Rating EF-0
Est. Peak Winds 75 mph
Path Length 0.93 miles
Max Width 50 yds
Injuries/Deaths 0 injuries or death

Summary:

The tornado flattened corn along its entire path as it
moved east.  The tornado also moved across one
property, snapping one tree which landed on a house
and snapping numerous branches.  A shed was also
destroyed by the tornado with debris being blown at
least 1/4 mile east of the shed.

Track Map

Track Map EF-Scale

Downloadable KMZ File

 

 

Tornado - Lake Sarah
Murray County

Date August 17, 2019
Time (Local) 11:14 - 11:16 PM CDT
EF Rating EF-0
Est. Peak Winds 70 mph
Path Length 1.15 miles
Max Width 50 yds
Injuries/Deaths 0 injuries or death

Summary:

The tornado touched a miles south of Lake Sarah 
and flattened corn along its path.  As the tornado
neared the southeast end of Lake Sarah, it move
through a farmstead destroying one shed.  The
tornado lifted as it approached the water.

Track Map

Track Map EF-Scale

Downloadable KMZ File

 

 

Tornado - Rural Cottonwood County
Cottonwood County

Date August 17, 2019
Time (Local) 11:25 - 11:26 PM CDT
EF Rating EF-0
Est. Peak Winds 70 mph
Path Length 0.51 miles
Max Width 50 yds
Injuries/Deaths 0 injuries or death

Summary:

The tornado briefly touched down near Minnesota 
Highway 62 7 miles west of Windom.  The tornado
flattened corn along its path.

Track Map

Track Map EF-Scale

Downloadable KMZ File

 

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0
Weak
65-85 mph		 EF1
Moderate
86-110 mph		 EF2
Significant
111-135 mph		 EF3
Severe
136-165 mph		 EF4
Extreme
166-200 mph		 EF5
Catastrophic
200+ mph
ef-scale

Photos & Video

Tornado, Large Hail, and Wind Damage

Damage Photos from Rock Rapids, Tornado (EF-1)
Damaged Silo near Rock Rapids Tree damage near Rock Rapids Farm Building damage near Rock Rapids Grain Bin damage near Rock Rapids
Damaged silo near Rock Rapids
(JD Hommes)		 Tree damage near Rock Rapids
(JD Hommes)		 Damage to cow confinement near Rock Rapids Grain bin damage near Rock Rapids
(Anonymous)
Photo Photo Photo Photo
Damage to hog confinement near Rock Rapids One power pole was snapped and 4 others leaning near Rock Rapids. Numerous shingles removed from roof near Rock Rapids. Tree snapped near Rock Rapids.
Damage Photos from Hadley, Tornado (EF-1)
Photo Photo Photo Photo
Roof damage to shed near Hadley.  Several trusses were also broken. Tree damage and numerous broken branches in Hadley Trees uprooted in Hadley Additional tree damage in Hadley
Photo Photo Photo Photo
Garage destroyed with van remaining on concrete slab where the garage had been. Trees snapped in foreground. Debris from destroyed garage can be seen on the grass. Flattened corn near Hadley. Note the corn in the background turns right (southeast) toward the tornado track. Outbuilding with door damaged.
Damage Photos from Reading, Minnesota Tornado (EF-0) Damage Photo from Lake Sarah, Minnesota Tornado (EF-0)
Flattened Corn near Reading, MN Damage to roof near Reading Minnesota Damaged storage building near Lake Sarah, MN Damaged storage building near Lake Sarah, MN
Flattened corn near Reading, MN
(James Joens)		 Damage to roof near Reading, Minnesota Damage to outbuilding near Lake Sarah, Minnesota (Parker McNeil) Corn flattened south of Lake Sarah
(Parker McNeil)
Damage Photos from Iona, Minnesota Tornado (EF-0) Damage Photos from rural Murray County, Minnesota Tornado (EF-0)
Photo Photo Photo Photo
Corn flattened. Photo was taken two days after tornado. (Brad Gass)  Pine tree snapped half way up and several headstones were toppled (Brad Gass) Tree snapped and landing on house, damaging roof. (Timothy Moline) Shed destroyed (Timothy Moline)
Wind damage photos from Wahpeton and Okoboji, Iowa
Photo Photo Photo Photo
Barn roof partially taken off. (Mike Ehret) Tin from barn roof wrapped around tree to the east of the barn. (Mike Ehret) Roof to home damaged by fallen branch. Tree snapped with other branches removed from trees in the background.
Photo Photo Photo Photo
Garage door was partially blown in and 3 windows were blown in on the second floor. North wall of warehouse blown out after west facing garage door gives way. Second floor east wall blown out as a result of windows giving way on the west side of building. Roof damaged by large limb falling on ti.
Other damage photos
Photo Photo Photo Photo
Corn flattened by tornado 7 miles west of Windom, Minnesota
(Paul Johnson)		 Grain bin damaged by 80-85 mph winds near Sibley, Iowa
(Rochelle Jacobsma)		 Trees branches down in Pipestone, Minnesota 
(Pipestone Star newspaper)		 Large hail near Lake Andes
(Rachel Bergin Kaczor)

Radar

Squall line and tornadoes from August 17, 2019

Loop of Radar Reflectivity Loop of Radar Velocity Radar Image Radar Image
Loop of Radar Reflectivity Loop of Radar Velocity Radar Image as Tornado was south of Hadley, Minnesota
at 10:57 PM CDT		 Radar Image as Tornado was south of Rock Rapids, Iowa
at 10:39 PM CDT
Radar Image Radar Image Radar Image Radar Image
Radar Image as the tornado was south of Iona, Minnesota
at 10:59 PM CDT		 Radar Image as the tornado was northwest of Reading, Minnesota
at 10:59 PM CDT		 Radar Image as the tornado was in rural Murray County west of Lake Shetek at 11:06 PM CDT Radar Image as the tornado was south of Lake Sarah
at 11:14 PM CDT
Radar Image      
Radar Image as the tornado was in rural Cottonwood County west of Windom at 11:25 PM CDT      

Storm Reports & Rainfall

Map of Storm Reports from the evening of August 17, 2019

Map of wind damage around Lake Okoboji Iowa List of Rainfall Reports from Volunteer Observers List of Rainfall Reports from Automated Gauges
Map showing the locations where damage to trees, homes and businesses were reported around Lake Okoboji. Rainfall reports from volunteer observers Rainfall reports from automated gauges
Local Storm Reports (timestamps are UTC)
Report Time County Location ST Event Type Mag. Remark
Sat Aug 17 2019 23:10:00 Charles Mix 2 SSW Geddes SD HAIL 1.75 lots of rain, and hail occurred for 40 minutes.
Sat Aug 17 2019 23:28:00 Charles Mix Pickstown SD HAIL 0.7  
Sat Aug 17 2019 23:30:00 Charles Mix Pickstown SD HAIL 1.5 picture received via social media.
Sun Aug 18 2019 00:14:00 Gregory 6 NNW Dixon SD HAIL 1.5  
Sun Aug 18 2019 00:16:00 Charles Mix 2 N Lake Andes SD HAIL 0.88  
Sun Aug 18 2019 00:17:00 Beadle 2 SSE Wessington SD HAIL 0.88 dime to nickel sized hail with heavy rain.
Sun Aug 18 2019 00:19:00 Beadle 3 SSE Wessington SD HAIL 1.25 car dented due to the hail.
Sun Aug 18 2019 00:30:00 Charles Mix 2 N Lake Andes SD HAIL 2  
Sun Aug 18 2019 00:35:00 Brule Chamberlain SD TSTM WND GST 56  
Sun Aug 18 2019 00:46:00 Aurora White Lake SD TSTM WND GST 61 sdsu station.
Sun Aug 18 2019 00:47:00 Brule 5 WNW White Lake SD HAIL 1.75  
Sun Aug 18 2019 00:50:00 Charles Mix 14 W Platte SD TSTM WND GST 51 rwis station.
Sun Aug 18 2019 00:52:00 Charles Mix 4 ENE Lake Andes SD HAIL 1.25 report via social media.
Sun Aug 18 2019 00:53:00 Charles Mix 6 N Ravinia SD HAIL 1.5  
Sun Aug 18 2019 00:55:00 Charles Mix 6 S Armour SD HAIL 1.25 report via mping.
Sun Aug 18 2019 01:10:00 Aurora Plankinton SD TSTM WND GST 65 rwis station.
Sun Aug 18 2019 01:35:00 Davison 2 N Mitchell SD TSTM WND GST 53  
Sun Aug 18 2019 01:38:00 Charles Mix Platte SD HAIL 1.25 report via social media.
Sun Aug 18 2019 01:40:00 Sanborn Forestburg SD TSTM WND GST 55 rwis station.
Sun Aug 18 2019 01:45:00 Davison 2 N Mitchell SD TSTM WND GST 61  
Sun Aug 18 2019 02:02:00 Kingsbury 7 W Erwin SD HAIL 0.75  
Sun Aug 18 2019 02:25:00 Miner Canova SD TSTM WND GST 58 cwop station.
Sun Aug 18 2019 02:48:00 Moody 10 N Colman SD HAIL 0.5  
Sun Aug 18 2019 02:53:00 Lake Madison SD TSTM WND GST 59  
Sun Aug 18 2019 03:10:00 Moody 5 ESE Egan SD TSTM WND DMG   severe damage to farm outbuilding. winds estimated 75 mph.
Sun Aug 18 2019 03:12:00 Moody Flandreau SD TSTM WND GST 54 sdsu station.
Sun Aug 18 2019 03:16:00 Hutchinson Tripp SD HAIL 1 mping station.
Sun Aug 18 2019 03:27:00 Pipestone Pipestone MN TSTM WND GST 60 some power outages reported around town.
Sun Aug 18 2019 03:32:00 Pipestone Pipestone MN TSTM WND GST 60 some power outages reported around town.
Sun Aug 18 2019 03:35:00 Rock Luverne MN TSTM WND GST 54  
Sun Aug 18 2019 03:35:00 Brookings Volga SD HEAVY RAIN 1.31 rain fell in approx 45 minutes.
Sun Aug 18 2019 03:41:00 Lyon 1 SE Rock Rapids IA TORNADO   time estimated based on radar. additional detail from storm survey will be complied monday, 8-19-2019.
Sun Aug 18 2019 03:48:00 Nobles 6 NNW Lismore MN TSTM WND DMG   garage blown off of foundation. numerous large tree limbs down.
Sun Aug 18 2019 03:53:00 Nobles Wilmont MN TSTM WND DMG   power lines down in wilmont. picture via social media.
Sun Aug 18 2019 03:56:00 Murray Hadley MN TSTM WND DMG   structural damage to a pair of garages in town. one garage blown off its foundation with cinder blocks from foundation rolled northeast. additional damage to trees in the city.
Sun Aug 18 2019 03:57:00 Murray Hadley MN TORNADO   time estimated based on radar. additional detail from storm survey will be compiled monday, 8-19-2019.
Sun Aug 18 2019 03:59:00 Nobles 5 SE Wilmont MN TORNADO   start of damage path. trees uprooted with several large branches down.
Sun Aug 18 2019 03:59:00 Murray 1 S Iona MN TORNADO   start of damage path. corn flattened.
Sun Aug 18 2019 04:01:00 Osceola Sibley IA TSTM WND DMG   damage to metal shed and many trees down. report via social media.
Sun Aug 18 2019 04:01:00 Osceola 1 SSW Sibley IA TSTM WND DMG   several grain bins damaged. road signs bent over on the south exit to sibley from highway 60.
Sun Aug 18 2019 04:02:00 Osceola 2 SE Sibley IA TSTM WND DMG   damage to grain bins. bolts holding empty bin in place broken with bin lifted/shifted from original position. top collapsed in on northwest side. wind estimated 85 mph.
Sun Aug 18 2019 04:03:00 Nobles 8 NNW Worthington MN TORNADO   end of 4 mile damage path.
Sun Aug 18 2019 04:07:00 Nobles 2 NE Worthington MN TSTM WND GST 56  
Sun Aug 18 2019 04:08:00 Murray 6 WNW Currie MN TORNADO   start of nearly mile long damage path. over the path, corn was flattened, several trees damaged and an old barn destroyed.
Sun Aug 18 2019 04:14:00 Murray 6 S Garvin MN TORNADO   start of slightly over one mile long damage path. during the two-minute tornado, some damage was done to farm outbuildings and corn was flattened.
Sun Aug 18 2019 04:24:00 Lyon Marshall MN HEAVY RAIN 1.37 1 hour rainfall total.
Sun Aug 18 2019 04:24:00 Dickinson 3 ESE Harris IA HAIL 0.88  
Sun Aug 18 2019 04:25:00 Dickinson 3 SSE Lake Park IA TSTM WND GST 54  
Sun Aug 18 2019 04:25:00 Dickinson Lake Park IA TSTM WND GST 54  
Sun Aug 18 2019 04:25:00 Cottonwood 4 NW Wilder MN TORNADO   start of 1/2 mile path. corn flattened and shredded. max path width of 20 yards.
Sun Aug 18 2019 04:30:00 Dickinson 1 WNW Wahpeton IA TSTM WND DMG   roof damage to a small barn. wind estimated 75 mph.
Sun Aug 18 2019 04:32:00 Dickinson 1 NNW Wahpeton IA TSTM WND DMG   large branches down, up to 3 inches in diameter.
Sun Aug 18 2019 04:35:00 Jackson Jackson MN TSTM WND GST 56  
Sun Aug 18 2019 04:35:00 Dickinson 1 SSE Okoboji IA TSTM WND DMG   trees uprooted. wind estimated 90 mph.
Sun Aug 18 2019 04:36:00 Murray 4 N Currie MN HEAVY RAIN 1.46 1 hour rainfall total.
Sun Aug 18 2019 04:40:00 Dickinson Okoboji IA TSTM WND DMG   2 large tree branches down blocking lakeshore drive.
Sun Aug 18 2019 04:45:00 Cottonwood Windom MN TSTM WND DMG   tree branches down blocking the road at 12th street and miller ave on the east side of town.
Sun Aug 18 2019 04:50:00 Murray 2 W Dovray MN TSTM WND GST 59 rwis station.
Sun Aug 18 2019 04:55:00 Lyon Marshall MN HEAVY RAIN 2.23 1.5 hour rainfall total.
Sun Aug 18 2019 05:55:00 Dixon 2 S Newcastle NE HAIL 0.88  
Sun Aug 18 2019 06:00:00 Lyon Tracy MN HEAVY RAIN 3.56  
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