EF1 tornado, Fibre to Big Spg, Tennessee, March 2, 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

March 2, 2012

Touchdown

8:45 PM EST (01:45 UTC)

Lifted

8:50 PM EST (01:50 UTC)

On the ground

5 minutes

Path length

2.5 miles (4.0 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$100,000

County

Claiborne County

Touchdown point

36.581, -83.532

Lift-off point

36.597, -83.492

Record number

1203021945-01

A deepening low pressure system moved northeast from the Mid Mississippi Valley through the Great Lakes initially driving a warm front northward through the Southern Appalachian region during the afternoon. The associated cold front swept across the area late Friday night. A one hundred knot upper level jet positioned over a 50 knot low level jet resulted in a strongly sheared environment. The intense shear and moderate instability produced an atmosphere conducive to long-lived, discrete, supercell thunderstorms. A total of 9 tornadoes ranging in intensity from EF-0 to EF-3 produced widespread damage and nearly 50 injuries to East Tennessee residents in the path of the storms.

An EF-2 tornado with a maximum wind speed of 120 mph created a damage path 2.6 miles in length and 250 yards wide across the northern part of Harrogate. Along the tornado track, 5 homes were destroyed, 7 suffered major damage, and 17 had minor damage. Also, four residents were injured in the storm.

This tornado formed in Claiborne County, TN, then moved northeast into Lee County, VA. In Claiborne County, the tornado was rated as EF1 with maximum winds of 90 mph. It damaged 5 homes, with one home receiving major damage. It also downed numerous trees. ||The combined tornado path for Claiborne and Lee Counties extended 4.9 miles.

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

24 minutes of warning. NWS MRX issued a tornado warning for this county at 01:21 UTC, 24 minutes before the tornado touched down, in force until 02:00 UTC.

The county was under a tornado watch, issued at 20:20 UTC and running to 03:53 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 00:30 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.

Middlesboro-Bell (1A6), 20 km from the path, in the two hours either side.

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

The Knoxville radar (KMRX), 48 km away, was scanning. The volume nearest the touchdown began at 01:46 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 TennesseeEvery tornado in Tennessee since 1950Warnings in force in Tennessee nowThe forecast where you are

69 more were confirmed in the United States that day.

All 70 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.