Tornadoes · United States · Mississippi · 1974

F3 tornado, Simpson County, Mississippi, February 21, 1974

This F3 tornado ran 14.2 miles across Simpson County on February 21, 1974, touching down at 4:09 PM CDT 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
February 21, 1974
Touchdown
4:09 PM CDT (21:09 UTC)
Path length
14.2 miles (22.8 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
Property damage
$5,000 to $50,000
County
Simpson County
Touchdown point
31.770, -89.950
Lift-off point
31.900, -89.770
Record number
43

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.

Jackson, MS (KJAN), 12:00Z

9.2 hours before the tornado, 58 km from the path. February 21, 1974.

Skew-T log-pSkew-T log-p diagram, Jackson, MS at 12:00Z on 1974-02-21Temperature 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 -8777, lifted condensation level 620 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, Jackson, MS at 12:00Z on 1974-02-21The 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 400 square meters per square second, 0 to 6 km bulk shear 55 knots.1939587897117Sfc1 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
-8777 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
620 m above ground
0-6 km bulk shear
55 kt
0-1 km bulk shear
39 kt
0-1 km storm-relative helicity
400 m²/s²
0-3 km storm-relative helicity
432 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
2.9 K/km

Open this sounding in Storm Lab

Jackson, MS (KJAN), 00:00Z

2.8 hours after it, 58 km from the path. February 22, 1974.

Skew-T log-pSkew-T log-p diagram, Jackson, MS at 00:00Z on 1974-02-22Temperature 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 -11259, lifted condensation level 1275 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, Jackson, MS at 00:00Z on 1974-02-22The 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 -118 square meters per square second, 0 to 6 km bulk shear 87 knots.1939587897117Sfc1 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
-11259 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1275 m above ground
0-6 km bulk shear
87 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
-118 m²/s²
0-3 km storm-relative helicity
-172 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

The surface observations

Jackson/Thompson (JAN), 58 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:00 UTC7265180° 20 kt331000.3-TSRA
20:14 UTC200° 18 kt321000.3
20:16 UTC200° 20 kt271000
21:00 UTC5755240° 17 kt261003-TSRA
21:26 UTC220° 12 kt1003
22:00 UTC5854230° 10 kt1002.7
22:25 UTC250° 10 kt1002.4
23:00 UTC5952200° 13 kt1003

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

This ground now

The live radar over the trackEvery 1974 tornado in MississippiEvery tornado in Mississippi since 1950Warnings in force in Mississippi nowThe forecast where you are

The other tornadoes of February 21, 1974

5 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
February 219:11 AM CDTF1Jefferson, TX0.110$5,000 to $50,000
February 219:50 AM CDTF1Evangeline Parish, LA0.210$500 to $5,000
February 213:30 PM CDTF3Lawrence, MS9.820013$50,000 to $500,000
February 214:14 PM CDTF1East Feliciana Parish, LA5.717$5,000 to $50,000
February 214:30 PM CDTF1Jefferson Parish, LA1.013$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.