Tornadoes · United States · Tennessee · 1993

F3 tornado, Roane, Loudon and Blount counties, Tennessee, February 21, 1993

This F3 tornado ran 30.0 miles across Roane, Loudon and Blount counties on February 21, 1993, touching down at 5:05 PM EST and reaching 100 yards wide. It killed 1 person and injured 55, and did $5,000 to $50,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 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. F3158 to 206 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. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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
F3
Date
February 21, 1993
Touchdown
5:05 PM EST (22:05 UTC)
Path length
30.0 miles (48.3 km)
Path width
100 yards (91 m)
Deaths
1
Injuries
55
Property damage
$5,000 to $50,000
Counties
Roane, Loudon and Blount counties
Touchdown point
35.830, -84.420
Lift-off point
35.750, -84.000
Record number
29

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Issued (UTC)ExpiredProductOffice
21:12 UTC22:15 UTCSevere Thunderstorm WarningMRX
21:52 UTC22:30 UTCSevere Thunderstorm WarningMRX

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 06:39 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.

Nashville Metro, TN (KBNA), 12:00Z

10.1 hours before the tornado, 218 km from the path. February 21, 1993.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 1993-02-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -8565, lifted condensation level 649 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Nashville Metro, TN at 12:00Z on 1993-02-21The 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 442 square meters per square second, 0 to 6 km bulk shear 44 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
0 J/kg
Mixed-layer CIN
-8565 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
649 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
46 kt
0-1 km storm-relative helicity
442 m²/s²
0-3 km storm-relative helicity
498 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

Nashville Metro, TN (KBNA), 00:00Z

1.9 hours after it, 218 km from the path. February 22, 1993.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 00:00Z on 1993-02-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 40 joules per kilogram, CIN -39, lifted condensation level 2393 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, Nashville Metro, TN at 00:00Z on 1993-02-22The 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 54 square meters per square second, 0 to 6 km bulk shear 42 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
40 J/kg
Mixed-layer CIN
-39 J/kg
Surface CAPE
35 J/kg
Mixed-layer LCL
2393 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
112 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
8.6 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1993 tornado in TennesseeEvery tornado in Tennessee since 1950Warnings in force in Tennessee nowThe forecast where you are

The other tornadoes of February 21, 1993

21 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
February 219:05 AM CSTF1Claiborne, MS4.073$5,000 to $50,000
February 211:52 PM CSTF3Putnam, TN10.01006$50,000 to $500,000
February 212:35 PM CSTF0Cumberland, TN5.023$50,000 to $500,000
February 213:35 PM ESTF0Fleming, KY1.050$50,000 to $500,000
February 213:50 PM ESTF0Henry, KY1.050$5,000 to $50,000
February 214:15 PM ESTF1Scioto, OH5.073$50,000 to $500,000
February 214:35 PM ESTF3Anderson, TN16.01503$500,000 to $5 million
February 215:10 PM ESTF1Meigs, OH8.0733$50,000 to $500,000
February 215:20 PM ESTF1Roane, TN3.023$50,000 to $500,000
February 215:45 PM ESTF3McMinn, TN19.07317$50,000 to $500,000
February 216:00 PM CSTF3Cherokee, AL19.01005$50,000 to $500,000
February 217:00 PM ESTF3Polk, GA9.0880135$500,000 to $5 million
February 217:20 PM ESTF0Gordon, GA0.230$50,000 to $500,000
February 217:50 PM ESTF1Bartow, GA1.0501$50,000 to $500,000
February 218:15 PM ESTF3Cobb, GA8.08803$5 million to $50 million
February 219:30 PM ESTF1Heard, GA7.05001$500,000 to $5 million
February 219:50 PM ESTF1Hall, GA4.03301$500,000 to $5 million
February 219:55 PM ESTF1Anderson, SC1.5200$50,000 to $500,000
February 2111:20 PM ESTF2Pike, GA8.010012$500,000 to $5 million
February 2111:45 PM ESTF1Meriwether, GA12.06001$500,000 to $5 million
February 2112:15 AM ESTF1Lexington, SC0.44502$500,000 to $5 million

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.