Tornadoes · United States · Tennessee · 1993

F3 tornado, McMinn and Monroe counties, Tennessee, February 21, 1993

This F3 tornado ran 19.0 miles across McMinn and Monroe counties on February 21, 1993, touching down at 5:45 PM EST and reaching 73 yards wide. It killed nobody and injured 17, and did $50,000 to $500,000 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
5:45 PM EST (22:45 UTC)
Path length
19.0 miles (30.6 km)
Path width
73 yards (67 m)
Deaths
0
Injuries
17
Property damage
$50,000 to $500,000
Counties
McMinn and Monroe counties
Touchdown point
35.430, -84.500
Lift-off point
35.270, -84.180
Record number
32

The forecast that day

The Storm Prediction Center had this point in a Moderate 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.

Athens Municipal, GA (KAHN), 12:00Z

10.8 hours before the tornado, 182 km from the path. February 21, 1993.

Skew-T log-pSkew-T log-p diagram, Athens Municipal, GA 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 -10776, lifted condensation level 578 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, Athens Municipal, GA 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 582 square meters per square second, 0 to 6 km bulk shear 47 knots.1939587897Sfc1 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
-10776 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
578 m above ground
0-6 km bulk shear
47 kt
0-1 km bulk shear
56 kt
0-1 km storm-relative helicity
582 m²/s²
0-3 km storm-relative helicity
571 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.2 K/km

Open this sounding in Storm Lab

Athens Municipal, GA (KAHN), 00:00Z

1.2 hours after it, 182 km from the path. February 22, 1993.

Skew-T log-pSkew-T log-p diagram, Athens Municipal, GA 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 0 joules per kilogram, CIN 0, lifted condensation level NaN 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, Athens Municipal, GA 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 478 square meters per square second, 0 to 6 km bulk shear 61 knots.1939587897Sfc1 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
0 J/kg
Surface CAPE
400 J/kg
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
61 kt
0-1 km bulk shear
40 kt
0-1 km storm-relative helicity
478 m²/s²
0-3 km storm-relative helicity
577 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.1
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

The surface observations

Knoxville Municipal (TYS), 61 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
00:00 UTC

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

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 215:05 PM ESTF3Roane, TN30.0100155$5,000 to $50,000
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 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.