EF3 tornado, Chapman to Corydon, Kentucky, November 17, 2013

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 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 mphthis tornado

   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

EF3

Date

November 17, 2013

Touchdown

2:41 PM CST (20:41 UTC)

Lifted

3:00 PM CST (21:00 UTC)

On the ground

19 minutes

Path length

14.1 miles (22.7 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$750,000

Counties

Union and Henderson counties

Touchdown point

37.701, -87.940

Lift-off point

37.744, -87.688

Record number

1311171441-01

34 damage points were recorded along this path by NWS PAH, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF3. The highest wind the damage implies is 145 mph.

• steel I beams twisted and complete failure of doors

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

Clusters of supercell thunderstorms moved rapidly east around 50 knots across western Kentucky during the afternoon. Some of these storms produced tornadoes. Low level wind shear was very strong, with 0 to 1 km bulk shear near 50 knots. This shear was present amidst decent instability for late fall, with mixed-layer capes of 500 to 1000 j/kg. One supercell cluster moved east from the Paducah area along the Western Kentucky Parkway. The other supercell cluster moved east across the far northwest counties of Kentucky, passing south of Evansville and then across the Owensboro area. The storms initiated over Missouri along a pre-frontal low pressure trough, then moved east across the Lower Ohio Valley. Strong southerly surface winds ahead of the storms gusted up to 50 mph during the early morning hours. An off-duty meteorologist measured a gust to 50 mph in Calvert City in Marshall County.

The tornado began just northwest of Morganfield, then tracked north of and parallel to U.S. Highway 60. A church roof was lifted and blown sideways. There were numerous homes with roof damage and some substantial structural damage. One home sustained total roof loss. Numerous hardwood trees were snapped or uprooted, some of which were very large. Several barns and outbuildings were destroyed. One mobile home slid off its foundation. Another mobile home disintegrated, with no walls, flooring, or roofing found. The steel I-beam undercarriage was twisted. A large metal storage building was destroyed. The steel I-beams supporting the roof were twisted. This metal building, about a mile north of Waverly, is where the most intense damage was located. Peak winds were estimated near 145 mph. There were several visual sightings of the tornado by trained spotters, along with video. The tornado continued across the Henderson County line into the Corydon area.

The tornado entered Henderson County just north of U.S. Highway 60 near the community of Kings Mill. The tornado passed through the center of Corydon just before lifting on the east side of town. The most intense damage in Henderson County was in Corydon, where the roof was blown off a house and some other houses sustained considerable roof damage. Peak winds at this location were estimated near 120 mph. The other damage in Henderson County was rated EF-0 or EF-1.

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

18 minutes of warning. NWS PAH issued a tornado warning for this county at 20:23 UTC, 18 minutes before the tornado touched down, in force until 21:00 UTC.

The county was under a tornado watch, issued at 16:43 UTC and running to 22:48 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 Moderate Risk, with a 0.15 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 20:02 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.

Henderson City (EHR), 15 km from the path, in the two hours either side.

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

The Evansville,IN radar (KVWX), 60 km away, was scanning. The volume nearest the touchdown began at 20:40 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 2013 tornado in KentuckyEvery tornado in Kentucky since 1950Warnings in force in Kentucky nowThe forecast where you are

75 more were confirmed in the United States that day.

All 76 of them

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.