EF1 tornado, Collegedale to Hopewell, Tennessee, April 27, 2011

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

April 27, 2011

Touchdown

3:02 PM EDT (19:02 UTC)

Lifted

3:18 PM EDT (19:18 UTC)

On the ground

16 minutes

Path length

17.0 miles (27.4 km)

Path width

120 yards (110 m)

Deaths

1

Injuries

0

Property damage

$125,000

Counties

Hamilton and Bradley counties

Touchdown point

35.040, -85.070

Lift-off point

35.197, -84.859

Record number

1104271302-01

Favorable atmospheric conditions resulted in a deadly tornado outbreak across east Tennessee on the 27th. The thunderstorms produced more than 50 tornadoes across the east Tennessee area with 32 deaths and more than 200 injured. The tornadoes produced from light to heavy damage to hundreds of homes and businesses. Hail as large as baseballs was also reported.

Ooltewah-to-Cleveland Tornado. A NWS storm survey reported an EF1 tornado touched down about 2 miles south of Ooltewah and tracked NNE through Ooltewah to near on I-75 at about mile marker 12. The path then turned more NE (at 35.101N/85.020W) to the Bradley County line. The 90 mph wind produced minor to moderate roof damage on a few homes and downed numerous trees.

Ooltewah-to-Cleveland Tornado. An EF1 tornado continued its path to the northeast from Hamilton county almost parallel to I-75 into western Bradley County. The tornado path showed a slight right bend at near 35.140N/84.993W, then continued to the northeast into the north side of Cleveland. The 90 mph wind downed numerous trees and slightly to moderately damaged several roofs throughout its path. A 56 year old man was killed due to flying debris and trees landing on the vehicle he was driving.

The 5NNW Cleveland Tornado. A NWS storm survey reported an EF0 tornado touched down briefly northwest of Cleveland. It had a path width of 50 yards and a path length of 1.78 miles. The 80 mph wind downed several trees.

W Cleveland Tornado. An NWS employee reported a EF1 tornado touched down near Cleveland. It had a 2 mile path length and a path width of 150 yards. The max wind of 80 mph downed trees and slightly damaged a few structures. This tornado brushed the Bradley County EMA office.

The deaths

1 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

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

35 minutes of warning. NWS MRX issued a tornado warning for this county at 18:27 UTC, 35 minutes before the tornado touched down, in force until 19:15 UTC.

The county was under a tornado watch, issued at 15:28 UTC and running to 20:36 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 High Risk, with a 0.30 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 16:29 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 Northeast Alabama radar (KHTX), 104 km away, was scanning. The volume nearest the touchdown began at 18:59 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 2011 tornado in TennesseeEvery tornado in Tennessee since 1950Warnings in force in Tennessee nowThe forecast where you are

209 more were confirmed in the United States that day.

All 210 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.