Tornadoes · United States · Ohio · 2009

EF1 tornado, Summithill to Denver, Ohio, July 11, 2009

From Summithill to Denver, this EF1 tornado ran 3.1 miles across Ross County on July 11, 2009, touching down at 3:55 PM EDT and reaching 440 yards wide. It killed nobody, and did $95,000 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 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.

The record

Rating
EF1
Date
July 11, 2009
Touchdown
3:55 PM EDT (19:55 UTC)
Lifted
4:01 PM EDT (20:01 UTC)
On the ground
6 minutes
Path length
3.1 miles (4.9 km)
Path width
440 yards (402 m)
Deaths
0
Injuries
0
Property damage
$95,000
Crop damage
$15,000
County
Ross County
Touchdown point
39.216, -83.112
Lift-off point
39.197, -83.060
Record number
0907111355-01

What the Weather Service recorded

A large area of thunderstorms moved through during the afternoon hours sparking straight line damaging winds, large hail, flash flooding, and tornadoes.

The tornado initially touched down near a grocery store near State Route 772 and Valley Road in Summithill where several trees were knocked down and uprooted. There were several intermittent touch downs between Summithill and Denver. To the southeast of Summithill, along Schaffer Road, approximately six homes and two mobile homes were damaged and numerous trees were snapped and uprooted. An eye-witness on Schaffer Road reported a rope tornado which had several brief touch downs. Further southeast in the Denver area, a home received substantial damage with a loss of the roof and some walls down. Portions of the roof were thrown 700 yards and wrapped around trees. There was also widespread crop damage in the area. Two barns off of Denver Road were completely destroyed and uprooted trees were observed intermittently along this path.

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

The warnings

7 minutes of warning. NWS ILN issued a tornado warning for this county at 19:48 UTC, 7 minutes before the tornado touched down, in force until 20:15 UTC.

Issued (UTC)ExpiredProductOffice
19:48 UTC20:15 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. The outlook in force was issued at 16:33 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), 12:00Z

7.9 hours before the tornado, 66 km from the path. July 11, 2009.

Skew-T log-pSkew-T log-p diagram, Cncnati-Daytn, OH at 12:00Z on 2009-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 912 joules per kilogram, CIN -49, lifted condensation level 1063 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 12:00Z on 2009-07-11The 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 52 square meters per square second, 0 to 6 km bulk shear 22 knots.1939587897Sfc1 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
912 J/kg
Mixed-layer CIN
-49 J/kg
Surface CAPE
1970 J/kg
Mixed-layer LCL
1063 m above ground
0-6 km bulk shear
22 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.5
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

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

4.1 hours after it, 66 km from the path. July 12, 2009.

Skew-T log-pSkew-T log-p diagram, Cncnati-Daytn, OH at 00:00Z on 2009-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 504 joules per kilogram, CIN -95, lifted condensation level 920 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 2009-07-12The 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 125 square meters per square second, 0 to 6 km bulk shear 43 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
504 J/kg
Mixed-layer CIN
-95 J/kg
Surface CAPE
2563 J/kg
Mixed-layer LCL
920 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.2
Supercell composite
5.8
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

The radar

The Cincinnati radar (KILN), 68 km away, was scanning. The volume nearest the touchdown began at 19:54 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
19:55 UTCTORNADO 111 Ssw ChillicotheRoss, OHEF-1 TORNADO TOUCHED DOWN INTERMITTENTLY ALONG A 3 MILE PATH BETWEEN SUMMITHILL AND DENVER...DESTROYING A HOME AND 2 BARNS AND DAMAGING 6 ADDITIONAL HOMES AND 2 MOBILE HOMES.
19:55 UTCTORNADO 111 Sw ChillicotheRoss, OHEF-1 TORNADO TOUCHED DOWN INTERMITTENTLY ALONG A 3 MILE PATH BETWEEN SUMMITHILL AND DENVER...DESTROYING A HOME AND 2 BARNS AND DAMAGING 6 ADDITIONAL HOMES AND 2 MOBILE HOMES.
19:59 UTCTSTM WND DMGBuchananPike, OH*** 5 INJ *** STRAIGHT-LINE WINDS DESTROYED 3 MOBILE HOMES. 2 OTHER MOBILE HOMES WERE PARTIALLY DAMAGED AND SEVERAL TREES WERE KNOCKED DOWN.
20:00 UTCTORNADO10 Ssw ChillicotheRoss, OHPOSSIBLE TORNADO NEAR S. R.772 AND VALLEY-SCHAFFER-DENVER ROAD OR NEAR SUMMITHILL. HOUSES DAMAGED...TREES AND POWER LINES DOWNED.
20:01 UTCTORNADOBuchananPike, OHPOSSIBLE TORNADO WITH TREES DOWN AND HOUSE TRAILERS DESTROYED.
20:10 UTCTSTM WND DMG3 S WaverlyPike, OHTREES DOWN AND SOME TOPPED EAST OF STE RTE 23 IN THE SHYVILLE AREA.
20:20 UTCTORNADO 15 Sse PiketonPike, OHTWO BRIEF TOUCHDOWNS OF AN EF-1 TORNADO NEAR LOOP ROAD AND BAILEY CHAPEL ROAD. AN ESTIMATED 25 TREES WERE KNOCKED DOWN OR UPROOTED AND A TRAMPOLINE WAS LIFTED OVER A FENCE.
20:32 UTCTSTM WND DMG9 Nne PortsmouthScioto, OHEXTENSIVE TREE DAMAGE ACROSS EASTERN SCIOTO COUNTY INCLUDING THE TOWNS OF MINFORD...WHEELERSBURG AND SOUTH WEBSTER.
20:54 UTCTSTM WND DMGWheelersburgScioto, OHSTRAIGHT-LINE WINDS UPROOTED AND DOWNED AN ESTIMATED 600 TREES ALONG A 5 MILE PATH. THE ROOF OF A HORSE BARN WAS TORN OFF ALONG WITH A TOTAL OF 6 BARNS DAMAGED.
21:00 UTCTSTM WND GST 70WheelersburgScioto, OHSEVERAL TREES DOWN OR TOPS SNAPPED OFF. GOLFBALL SIZE HAIL.
21:47 UTCHEAVY RAIN 3LucasvilleScioto, OHSTREETS AND RESIDENCES FLOODED.
22:00 UTCFLASH FLOODWheelersburgScioto, OHFLASH FLOODING REPORTED NEAR THE PORTER TOWNSHIP FIRE DEPARTMENT.

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

This ground now

The live radar over the trackEvery 2009 tornado in OhioEvery tornado in Ohio since 1950Warnings in force in Ohio nowThe forecast where you are

The other tornadoes of July 11, 2009

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 114:20 PM EDTEF1Pike, OH0.6100$5,000
July 115:40 PM EDTEF0Union, PA1.050$5,000
July 115:35 PM MDTEF0Elbert, CO0.150
July 116:55 PM MDTEF0Stark, ND4.030

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.