EF1 tornado, Deer Creek to Deacon, Indiana, July 10, 2017

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF1

Date

July 10, 2017

Touchdown

7:53 PM EDT (23:53 UTC)

Lifted

8:06 PM EDT (00:06 UTC)

On the ground

13 minutes

Path length

3.8 miles (6.2 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Crop damage

$5,000

Counties

Cass and Carroll counties

Touchdown point

40.641, -86.396

Lift-off point

40.640, -86.319

Record number

1707101753-01

2 damage points were recorded along this path by NWS IWX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

Northwest flow in the upper atmosphere allowed multiple waves to move across the area. The atmosphere had a high moisture content and was unstable. The waves interacted with the moisture and instability to produce the severe weather and heavy rain. Multiple rounds of thunderstorms moved over the same locations, creating the flooding problems. Several rounds of thunderstorms, from July 10th through the 13th, brought a tornado, damaging winds, large hail, and flooding to central Indiana.||On the evening of the 10th, scattered severe storms developed over northern portions of central Indiana along a nearly stationary warm front. The storms produced an EF0 tornado across far eastern Carroll County, continuing and intensifying as it moved into Cass County.

Synoptic quasi-stationary boundary was located across the forecast area, initially across northern parts during the morning and then sagging south as an upper level wave moved into the region during the late afternoon and evening hours. A morning complex of storms caused sporadic wind damage as well as some areal flooding. Subsidence behind the system kept any further development of storms limited until the approach of the wave. This wave, combined with the front and instability advected in from central Illinois all set the stage for increasing thunderstorm development. Several supercells developed, producing long lived wall clouds and two confirmed tornadoes. IN addition, training of convection caused flash flooding in some parts of Indiana and Ohio.

Mainly crop damage was observed on the Carroll County side of this EF1 tornado track before heading into Cass County. Overall, crop and tree damage, minor roof damage to a few barns and homes, as well as a recreational vehicle (RV) being lifted and destroyed is what was surveyed from this 95 mph maximum wind tornado.

A NWS survey of the area confirmed the touchdown of a tornado in Carroll county, which tracked east into Cass county. Most of the damage was confined to crops along the path. However, several trees were blown down off of S County Road 125 E and 200 E. A poorly anchored smaller barn was destroyed with a nearby larger barn suffering metal roofing damage. A home in the area also suffered minor damage. Maximum winds were estimated at around 95 mph.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

8 minutes of warning. NWS IND issued a tornado warning for this county at 23:45 UTC, 8 minutes before the tornado touched down, in force until 00:04 UTC.

The county was under a severe thunderstorm watch, issued at 21:01 UTC and running to 04:00 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:54 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The Northern Indiana radar (KIWX), 97 km away, was scanning. The volume nearest the touchdown began at 23:53 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2017 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are

6 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.