EF1 tornado, Floyds Knobs, Indiana, January 17, 2012

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

January 17, 2012

Touchdown

11:00 AM EST (16:00 UTC)

Lifted

11:02 AM EST (16:02 UTC)

On the ground

2 minutes

Path length

2.1 miles (3.4 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$10,000

County

Floyd County

Touchdown point

38.307, -85.889

Lift-off point

38.315, -85.851

Record number

1201171000-01

Deep low pressure moved across the southern Great Lakes the morning of January 17. A cold front associated with this storm swept southeast of the Ohio River during the early afternoon hours. Fueled by unseasonably warm and moist air, a squall line developed across southeastern Missouri and southern Illinois during the early morning and moved across all of southern Indiana during the late morning hours. Embedded within this line were several bowing segments and mesovorticies. Scattered wind damage and several brief tornadoes were reported. The nine tornadoes surveyed across both southern Indiana and central Kentucky made this date the most prolific regional January outbreak recorded.

An EF-1 tornado with estimated winds of 95 to 100 mph first touched down along East Riley Road, where a garage was destroyed. Multiple trees were downed further east along Binford Road. After crossing Paoli Pike just north of Interstate 265, and just before lifting, the tornado damaged some roofs at the Knob Point Apartments. Maximum wind speeds were estimated to be between 95 and 100 mph.

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

33 minutes of warning. NWS LMK issued a tornado warning for this county at 15:27 UTC, 33 minutes before the tornado touched down, in force until 16:00 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 General Thunderstorms Risk. The outlook in force was issued at 12:51 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 Louisville radar (KLVX), 38 km away, was scanning. The volume nearest the touchdown began at 15:58 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 2012 tornado in IndianaEvery tornado in Indiana since 1950Warnings in force in Indiana nowThe forecast where you are

11 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.