Tornadoes · United States · Michigan · 1976

F3 tornado, Macomb County, Michigan, March 20, 1976

This F3 tornado ran 17.1 miles across Macomb County on March 20, 1976, touching down at 7:40 PM EST and reaching 100 yards wide. It killed 1 person and injured 3, 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
March 20, 1976
Touchdown
7:40 PM EST (00:40 UTC)
Path length
17.1 miles (27.5 km)
Path width
100 yards (91 m)
Deaths
1
Injuries
3
Property damage
$50,000 to $500,000
County
Macomb County
Touchdown point
42.700, -82.970
Lift-off point
42.880, -82.730
Record number
133

What the Weather Service recorded

The deaths

1 direct deaths are recorded for this tornado, each with what Storm Data knows of it.

AgeSexWhereKind
Direct

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

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.

Detroit, MI (KFNT), 00:00Z

0.7 hours before the tornado, 48 km from the path. March 21, 1976.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 00:00Z 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 -8581, lifted condensation level 1285 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, Detroit, MI at 00:00Z 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 214 square meters per square second, 0 to 6 km bulk shear 47 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
-8581 J/kg
Surface CAPE
160 J/kg
Mixed-layer LCL
1285 m above ground
0-6 km bulk shear
47 kt
0-1 km bulk shear
37 kt
0-1 km storm-relative helicity
214 m²/s²
0-3 km storm-relative helicity
325 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

Detroit, MI (KFNT), 12:00Z

11.3 hours after it, 48 km from the path. March 21, 1976.

Skew-T log-pSkew-T log-p diagram, Detroit, MI 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 -16653, lifted condensation level 799 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, Detroit, MI 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 -90 square meters per square second, 0 to 6 km bulk shear 101 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
-16653 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
799 m above ground
0-6 km bulk shear
101 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
-90 m²/s²
0-3 km storm-relative helicity
-38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

The surface observations

Selfridge Angb (MTC), 20 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:00 UTC6152210° 14 kt28996.3
00:00 UTC6454220° 18 kt30995.6
01:00 UTC6052210° 24 kt34994.6-SHRA
02:00 UTC5852200° 16 kt22994.9

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

This ground now

The live radar over the trackEvery 1976 tornado in MichiganEvery tornado in Michigan since 1950Warnings in force in Michigan 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 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 2010:45 PM CSTF3Cullman, AL9.310017$500,000 to $5 million
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.