Tornadoes · United States · Mississippi · 1973

F3 tornado, Grenada and Tallahatchie counties, Mississippi, November 20, 1973

This F3 tornado ran 11.9 miles across Grenada and Tallahatchie counties on November 20, 1973, touching down at 3:30 PM CST and reaching 10 yards wide. It killed nobody, 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
November 20, 1973
Touchdown
3:30 PM CST (21:30 UTC)
Path length
11.9 miles (19.1 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
Property damage
$5,000 to $50,000
Counties
Grenada and Tallahatchie counties
Touchdown point
33.680, -90.050
Lift-off point
33.800, -89.900
Record number
995

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.

Little Rock, AR (KLIT), 12:00Z

9.5 hours before the tornado, 121 km from the path. November 20, 1973.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 1973-11-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 28 joules per kilogram, CIN -23, lifted condensation level 651 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Little Rock, AR at 12:00Z on 1973-11-20The 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 305 square meters per square second, 0 to 6 km bulk shear 55 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
28 J/kg
Mixed-layer CIN
-23 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
651 m above ground
0-6 km bulk shear
55 kt
0-1 km bulk shear
32 kt
0-1 km storm-relative helicity
305 m²/s²
0-3 km storm-relative helicity
353 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.6 K/km

Open this sounding in Storm Lab

Little Rock, AR (KLIT), 00:00Z

2.5 hours after it, 121 km from the path. November 21, 1973.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 00:00Z on 1973-11-21Temperature 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 -12754, lifted condensation level 1518 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Little Rock, AR at 00:00Z on 1973-11-21The 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 -107 square meters per square second, 0 to 6 km bulk shear 83 knots.1939587897117136Sfc1 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
-12754 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1518 m above ground
0-6 km bulk shear
83 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
-107 m²/s²
0-3 km storm-relative helicity
-263 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

The surface observations

Greenwood/Leflore (GWO), 29 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:00 UTC7761.88140° 14 kt1005.4
21:00 UTC7661.88140° 12 kt1005.1TSRA
21:37 UTC190° 7 kt1004.7
22:00 UTC7463140° 15 kt1004.1TSRA
23:00 UTC70.8865120° 8 kt1004.1TSRA

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

This ground now

The live radar over the trackEvery 1973 tornado in MississippiEvery tornado in Mississippi since 1950Warnings in force in Mississippi nowThe forecast where you are

The other tornadoes of November 20, 1973

10 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
November 2012:01 AM CSTF1Roger Mills, OK0.5307$50,000 to $500,000
November 2012:55 AM CSTF2Coffey, KS1.033$50,000 to $500,000
November 201:10 AM CSTF1Collin, TX0.1103$5,000 to $50,000
November 206:00 AM CSTF2Sevier, AR5.71006$50,000 to $500,000
November 2011:25 AM CSTF1Beauregard Parish, LA51.01001$5,000 to $50,000
November 201:35 PM CSTF1Morehouse Parish, LA1.0200$500,000 to $5 million
November 203:00 PM CSTF0Concordia Parish, LA1.5100$500 to $5,000
November 203:00 PM CSTF2Crenshaw, AL0.110$5,000 to $50,000
November 203:30 PM CSTF2Leflore, MS0.110$50,000 to $500,000
November 2010:00 PM CSTF1Washington, KS0.320$5,000 to $50,000

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.