Tornadoes · United States · Indiana · 2007
EF0 tornado, Knightsville to Harmony, Indiana, April 11, 2007
From Knightsville to Harmony, this EF0 tornado ran 0.1 miles across Clay County on April 11, 2007, touching down at 4:20 PM EDT and reaching 50 yards wide. It killed nobody, and did $3,000 of property damage.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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.
The record
- Rating
- EF0
- Date
- April 11, 2007
- Touchdown
- 4:20 PM EDT (20:20 UTC)
- Lifted
- 4:22 PM EDT (20:22 UTC)
- On the ground
- 2 minutes
- Path length
- 0.1 miles (0.2 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $3,000
- County
- Clay County
- Touchdown point
- 39.530, -87.100
- Lift-off point
- 39.530, -87.070
- Record number
- 0704111420-01
What the Weather Service recorded
Severe thunderstorms moved through central Indiana on the afternoon of 11 April 2007. The storms produced tornadoes, large hail, and damaging winds. The National Weather Service Indianapolis damage assessment teams confirmed four tornadoes in central Indiana. These tornadoes occurred from mini supercells.
The initial tornado touchdown was reported by a storm spotter at 4:20 P.M. EDT in Harmony, about 22 miles east of Terre Haute . Minor tree damage resulted from this storm in addition to damage to a metal carport and a shed. This tornado was rated EF0 on the Enhanced Fujita intensity scale with winds estimated around 70 mph.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 21:29 UTC | 22:00 UTC | Severe Thunderstorm Warning | IND |
| 21:32 UTC | 22:54 UTC | Severe Thunderstorm Watch | IND |
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 forecast that day
The Storm Prediction Center had this point in a Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:53 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 air that afternoon
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.
Lincoln, IL (KILX), 12:00Z
8.3 hours before the tornado, 147 km from the path. April 11, 2007.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -41256 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 520 m above ground
- 0-6 km bulk shear
- 43 kt
- 0-1 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 252 m²/s²
- 0-3 km storm-relative helicity
- 257 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.0 K/km
Lincoln, IL (KILX), 00:00Z
3.7 hours after it, 147 km from the path. April 12, 2007.
- Mixed-layer CAPE
- 7 J/kg
- Mixed-layer CIN
- -1 J/kg
- Surface CAPE
- 57 J/kg
- Mixed-layer LCL
- 749 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- -62 m²/s²
- 0-3 km storm-relative helicity
- -28 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 6.2 K/km
The radar
The Indianapolis radar (KIND), 72 km away, was scanning. The volume nearest the touchdown began at 20:21 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.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 19:56 UTC | HAIL 0.25 | 5 Wsw Brazil | Clay, IN | |
| 20:41 UTC | TSTM WND DMG | Knightsville | Clay, IN | CARPORT BLOWN INTO TREE |
| 20:41 UTC | HAIL 0.75 | 5 Ne Terre Haute | Vigo, IN | NEAR COAL BLUFF |
| 20:41 UTC | HAIL 1 | Greencastle | Putnam, IN | |
| 21:14 UTC | HAIL 0.25 | 3 Sw Terre Haute | Vigo, IN | HEAVY PEA SIZE HAIL ON I-70 AT MILE MARKER 5 |
| 21:17 UTC | HAIL 0.5 | 2 Sw Terre Haute | Vigo, IN | |
| 21:19 UTC | HAIL 0.88 | Dana | Vermillion, IN | |
| 21:27 UTC | HAIL 1 | 2 E Terre Haute | Vigo, IN | |
| 21:29 UTC | TORNADO | 7 S North Salem | Hendricks, IN | 1/2 MI NORTH OF US 36 AND SR75 |
| 21:37 UTC | TORNADO | 2 Se North Salem | Hendricks, IN | 500 N AND SR236 MOVING NE |
| 21:51 UTC | TSTM WND GST 50 | 7 S Spencer | Owen, IN | |
| 22:02 UTC | HAIL 0.75 | Jamestown | Hendricks, IN | |
| 22:08 UTC | HAIL 0.75 | Greencastle | Putnam, IN | |
| 22:24 UTC | HAIL 0.75 | 1 Nw Cloverdale | Putnam, IN | |
| 22:27 UTC | HAIL 0.75 | New Ross | Montgomery, IN | |
| 22:37 UTC | TORNADO | 4 E North Salem | Hendricks, IN | 625N AND 200W |
| 22:45 UTC | TSTM WND DMG | 1 S Lizton | Hendricks, IN | BARN DAMAGE...ROOF OFF 2 HOUSES...5 HOUSES DAMAGED |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2007 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are
The other tornadoes of April 11, 2007
9 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| April 11 | 3:14 PM CDT | EF1 | Jefferson, AL | 0.6 | 40 | $20,000 | ||
| April 11 | 3:47 PM CDT | EF1 | Chilton, AL | 1.0 | 200 | $11,000 | ||
| April 11 | 5:35 PM EDT | EF0 | Hendricks, IN | 0.1 | 50 | |||
| April 11 | 5:05 PM CDT | EF0 | Elmore, AL | 0.1 | 25 | $5,000 | ||
| April 11 | 5:18 PM CDT | EF1 | Tallapoosa, AL | 0.9 | 50 | $20,000 | ||
| April 11 | 6:37 PM EDT | EF1 | Hendricks, IN | 4.9 | 75 | $70,000 | ||
| April 11 | 5:54 PM CDT | EF1 | Macon, AL | 11.5 | 400 | $15,000 | ||
| April 11 | 7:25 PM EDT | EF2 | Hamilton, IN | 4.0 | 100 | $150,000 | ||
| April 11 | 7:30 PM EDT | EF1 | Tipton, IN | 0.1 | 100 | $32,000 |
What this means
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.
Sources
NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.