Tornadoes · United States · Ohio · 2012

EF0 tornado, Williams Corners, Ohio, September 7, 2012

This EF0 tornado ran 0.2 miles across Clermont County on September 7, 2012, touching down at 12:36 AM EDT and reaching 25 yards wide. It killed nobody, and did $40,000 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.

  1. EF065 to 85 mphthis tornado

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

  2. EF186 to 110 mph

    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.

The record

Rating
EF0
Date
September 7, 2012
Touchdown
12:36 AM EDT (04:36 UTC)
Lifted
12:37 AM EDT (04:37 UTC)
On the ground
1 minutes
Path length
0.2 miles (0.3 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
Property damage
$40,000
County
Clermont County
Touchdown point
39.173, -84.144
Lift-off point
39.175, -84.141
Record number
1209072236-01

What the Weather Service recorded

A strong trough helped to produce a quasi linear convective system that moved across the Ohio Valley during the late evening hours into the early morning hours. The main threats from this system were damaging winds, sub severe hail, and isolated weak tornadoes.

The tornado touched down near the intersection of Route 131 and Belfast-Owensville Road. Three homes and a barn with a garage sustained anywhere from minor to major roof damage. A porch was lifted from a home and thrown several yards. Based on the damage surveyed, the maximum wind speed of this tornado was estimated at 70 to 75 miles per hour.

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. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 01:10 UTC and running to 07:00 UTC.

Issued (UTC)ExpiredProductOffice
20:41 UTC01:10 UTCSevere Thunderstorm WatchILN
01:10 UTC07:00 UTCSevere Thunderstorm WatchILN
04:22 UTC05:00 UTCSevere Thunderstorm WarningILN
04:43 UTC05:02 UTCSevere Thunderstorm WarningILN
04:57 UTC05:45 UTCSevere Thunderstorm WarningILN
05:04 UTC05:20 UTCTornado WarningILN

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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 01:00 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.

Cncnati-Daytn, OH (KILN), 00:00Z

4.6 hours before the tornado, 41 km from the path. September 8, 2012.

Skew-T log-pSkew-T log-p diagram, Cncnati-Daytn, OH at 00:00Z on 2012-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 531 joules per kilogram, CIN -83, lifted condensation level 1512 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Cncnati-Daytn, OH at 00:00Z on 2012-09-08The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 20 square meters per square second, 0 to 6 km bulk shear 32 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
531 J/kg
Mixed-layer CIN
-83 J/kg
Surface CAPE
294 J/kg
Mixed-layer LCL
1512 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Cncnati-Daytn, OH (KILN), 12:00Z

7.4 hours after it, 41 km from the path. September 8, 2012.

Skew-T log-pSkew-T log-p diagram, Cncnati-Daytn, OH at 12:00Z on 2012-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -46897, lifted condensation level 777 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Cncnati-Daytn, OH at 12:00Z on 2012-09-08The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -235 square meters per square second, 0 to 6 km bulk shear 51 knots.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-46897 J/kg
Surface CAPE
3 J/kg
Mixed-layer LCL
777 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
-235 m²/s²
0-3 km storm-relative helicity
-296 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

The surface observations

Cincinnat/Lunken (LUK), 25 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
02:53 UTC7469230° 4 kt1005.1
03:28 UTC75.269.8180° 7 kt1004.7VCTS
03:53 UTC7869190° 11 kt1004.4-RA
04:10 UTC78.869.8200° 10 kt1004.1VCTS
04:27 UTC71.666.2310° 17 kt291006.4+TSRA
04:34 UTC6864.4310° 7 kt281006.4+TSRA BR
04:49 UTC69.866.2270° 7 kt171006.8+TSRA BR
04:53 UTC6966330° 9 kt171006.4+TSRA BR
05:02 UTC6866.2350° 5 kt1006.1+TSRA BR
05:10 UTC6866.2 3 kt1006.4VCTS +RA BR
05:22 UTC69.866.2 3 kt1006.8VCTS +RA BR
05:33 UTC6866.20° 0 kt1006.8RA BR
05:53 UTC6866170° 4 kt1006.8RA BR

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Cincinnati radar (KILN), 39 km away, was scanning. The volume nearest the touchdown began at 04:35 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)ReportWhereCountyRemark
04:12 UTCHAIL 0.885 Ene MiamisburgMontgomery, OH
04:13 UTCTSTM WND DMGKetteringMontgomery, OHTREES DOWN. TIME ESTIMATED BY RADAR.
04:36 UTCTORNADO 03 Wsw NewtonsvilleClermont, OHROOF DAMAGE TO SEVERAL HOMES NEAR THE INTERSECTION OF STATE ROUTE 131 AND BELFAST ROAD. DAMAGE TO AN OUTBUILDING...WITH SEVERAL TREES DOWNED.
04:42 UTCTSTM WND DMG2 Ene NewtonsvilleClermont, OHDAMAGE TO ROOVES AND SHINGLES AT SEVERAL HOMES ON TAYLOR PIKE. GARAGE DOORS ALSO DAMAGED...WITH A FEW TREES DOWNED.
04:46 UTCTSTM WND DMGGoshenClermont, OHLARGE BRANCHES BROKEN. TIME AND LOCATION ESTIMATED.

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

This ground now

The live radar over the trackEvery 2012 tornado in OhioEvery tornado in Ohio since 1950Warnings in force in Ohio nowThe forecast where you are

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.