Tornadoes · United States · Alabama · 1976

F3 tornado, Cullman County, Alabama, March 20, 1976

This F3 tornado ran 9.3 miles across Cullman County on March 20, 1976, touching down at 10:45 PM CST and reaching 100 yards wide. It killed nobody and injured 17, and did $500,000 to $5 million 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
March 20, 1976
Touchdown
10:45 PM CST (04:45 UTC)
Path length
9.3 miles (15.0 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
17
Property damage
$500,000 to $5 million
County
Cullman County
Touchdown point
34.220, -86.730
Lift-off point
34.270, -86.580
Record number
151

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.

Centreville/Bibb, AL (KCKL), 12:00Z

7.2 hours after it, 158 km from the path. March 21, 1976.

Skew-T log-pSkew-T log-p diagram, Centreville/Bibb, AL at 12:00Z on 1976-03-21Temperature 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 -13325, lifted condensation level 1513 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, Centreville/Bibb, AL at 12:00Z on 1976-03-21The 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 -160 square meters per square second, 0 to 6 km bulk shear 74 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
-13325 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1513 m above ground
0-6 km bulk shear
74 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
-160 m²/s²
0-3 km storm-relative helicity
2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.4 K/km

Open this sounding in Storm Lab

The surface observations

Cullman/Folsom_field_arpt (3A1), 19 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
03:00 UTC7058120° 6 kt1020.3
04:00 UTC7058120° 6 kt1020
05:00 UTC7260120° 9 kt1019
06:00 UTC7262130° 8 kt1018.3

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

This ground now

The live radar over the trackEvery 1976 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

The other tornadoes of March 20, 1976

47 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
March 2012:05 PM CSTF3Montgomery, IL8.8274$50,000 to $500,000
March 2012:25 PM CSTF2Saint Clair, IL39.0250$50,000 to $500,000
March 201:15 PM CSTF4Macon, IL63.780018$500,000 to $5 million
March 202:30 PM CSTF0Jasper, IL1.917$5,000 to $50,000
March 203:00 PM CSTF1Butler, MO0.117$5,000 to $50,000
March 204:20 PM ESTF1Calhoun, MI6.250$5,000 to $50,000
March 204:20 PM ESTF4Tippecanoe, IN16.73008$500,000 to $5 million
March 203:25 PM CSTF1Crawford, IL3.517$5,000 to $50,000
March 204:30 PM ESTF2Ionia, MI9.950$5,000 to $50,000
March 204:30 PM ESTF0Vigo, IN13.940$5,000 to $50,000
March 204:50 PM ESTF1Ingham, MI18.993$50,000 to $500,000
March 204:59 PM ESTF2Marshall, IN11.67710$50,000 to $500,000
March 204:10 PM CSTF1Scott, MO1.0171$5,000 to $50,000
March 205:10 PM ESTF2Putnam, IN24.9200$5,000 to $50,000
March 204:24 PM CSTF1Lafayette, MS0.1133$5,000 to $50,000
March 205:30 PM ESTF0Hamilton, IN1.030$50,000 to $500,000
March 205:35 PM ESTF0Hendricks, IN6.930$500 to $5,000
March 204:40 PM CSTF2Newton, MS19.8250$50,000 to $500,000
March 206:27 PM ESTF1Madison, IN5.1100$5,000 to $50,000
March 206:35 PM ESTF0Henry, IN0.117
March 205:45 PM CSTF1Noxubee, MS11.2100$5,000 to $50,000
March 206:15 PM CSTF3West Carroll Parish, LA to AR4.65032$500,000 to $5 million
March 206:15 PM CSTF2Richland Parish, LA17.067$50,000 to $500,000
March 207:15 PM ESTF4Oakland, MI3.8117155$5 million to $50 million
March 206:35 PM CSTF1West Carroll Parish, LA0.110$5,000 to $50,000
March 206:35 PM CSTF2Bolivar, MS4.34401$50,000 to $500,000
March 207:40 PM ESTF3Macomb, MI17.110013$50,000 to $500,000
March 208:00 PM ESTF1Mercer, OH3.850$5,000 to $50,000
March 207:00 PM CSTF2Sharkey, MS29.8440$5,000 to $50,000
March 208:00 PM CSTF1Barren, KY0.11010$50,000 to $500,000
March 208:15 PM CSTF2Yazoo, MS3.8150$5,000 to $50,000
March 208:20 PM CSTF3Webster, MS49.41,40019$50,000 to $500,000
March 208:20 PM CSTF1Madison, MS2.0100$5,000 to $50,000
March 209:00 PM CSTF2Lauderdale, AL1.0302$5,000 to $50,000
March 2010:15 PM ESTF0Medina, OH0.770$5,000 to $50,000
March 209:15 PM CSTF2Lowndes, MS0.5100$5,000 to $50,000
March 209:40 PM CSTF1Lamar, AL0.2201$5,000 to $50,000
March 2010:05 PM CSTF2Pickens, AL0.530$5,000 to $50,000
March 2010:08 PM CSTF1Madison, AL4.5100$50,000 to $500,000
March 2010:20 PM CSTF2Winston, AL0.5776$50,000 to $500,000
March 2010:22 PM CSTF2Madison, AL0.520$50,000 to $500,000
March 2010:22 PM CSTF0Madison, AL0.520$5,000 to $50,000
March 2010:25 PM CSTF1Wilson, TN7.3440$50,000 to $500,000
March 2010:25 PM CSTF1Madison, AL4.540$5,000 to $50,000
March 2010:49 PM CSTF0Blount, AL0.110$50 to $500
March 2010:50 PM CSTF3Blount, AL19.24011$50,000 to $500,000
March 2011:20 PM CSTF0Etowah, AL0.110$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.