Tornadoes · United States · Minnesota · 1973

F1 tornado, Becker County, Minnesota, June 16, 1973

This F1 tornado ran 5.2 miles across Becker County on June 16, 1973, touching down at 10:40 PM CDT and reaching 60 yards wide. It killed nobody, 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 mphthis tornado

    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 mph

    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
F1
Date
June 16, 1973
Touchdown
10:40 PM CDT (03:40 UTC)
Path length
5.2 miles (8.4 km)
Path width
60 yards (55 m)
Deaths
0
Injuries
0
Property damage
$50,000 to $500,000
County
Becker County
Touchdown point
46.850, -95.600
Lift-off point
46.900, -95.500
Record number
647

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.

International Fa, MN (KINL), 00:00Z

3.7 hours before the tornado, 253 km from the path. June 17, 1973.

Skew-T log-pSkew-T log-p diagram, International Fa, MN at 00:00Z on 1973-06-17Temperature 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 579 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 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, International Fa, MN at 00:00Z on 1973-06-17The 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 15 square meters per square second, 0 to 6 km bulk shear 17 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
0 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
579 m above ground
0-6 km bulk shear
17 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
13 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

International Fa, MN (KINL), 12:00Z

8.3 hours after it, 253 km from the path. June 17, 1973.

Skew-T log-pSkew-T log-p diagram, International Fa, MN at 12:00Z on 1973-06-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2 joules per kilogram, CIN 0, lifted condensation level 482 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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, International Fa, MN at 12:00Z on 1973-06-17The 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 12 square meters per square second, 0 to 6 km bulk shear 29 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
2 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
482 m above ground
0-6 km bulk shear
29 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.9 K/km

Open this sounding in Storm Lab

This ground now

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

The other tornadoes of June 16, 1973

24 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 161:45 AM CDTF0Crow Wing, MN20.130$500 to $5,000
June 162:12 PM ESTF1Pulaski, IN1.050$50,000 to $500,000
June 162:25 PM CDTF0McHenry, IL0.110
June 164:00 PM EDTF0Henrico, VA0.110under $50
June 163:15 PM CDTF0Cook, IL0.110
June 164:45 PM CDTF2Buchanan, MO6.01014$500,000 to $5 million
June 165:50 PM EDTF2Baltimore, MD0.1104$5,000 to $50,000
June 165:30 PM CDTF0Kankakee, IL0.110
June 166:50 PM EDTF1Harford, MD0.110$500 to $5,000
June 166:15 PM CDTF1Ransom, ND0.110
June 166:20 PM CDTF1Griggs, ND0.110
June 166:30 PM CDTF1Pittsburg, OK30.91002$5,000 to $50,000
June 166:45 PM CDTF0Clarke, IA1.050$5,000 to $50,000
June 168:05 PM EDTF1Lenawee, MI2.550$5,000 to $50,000
June 167:15 PM CDTF3Traill, ND0.110$50,000 to $500,000
June 167:30 PM CDTF1Adams, IL0.110
June 167:40 PM CDTF1Hancock, IL0.110
June 167:45 PM CDTF0Des Moines, IA0.5100$5,000 to $50,000
June 169:10 PM EDTF1Clark, IN0.120$5,000 to $50,000
June 168:20 PM CDTF1Adair, OK0.140$500 to $5,000
June 168:45 PM CDTF1Black Hawk, IA0.550$50,000 to $500,000
June 169:35 PM CDTF0Logan, IL0.110
June 169:35 PM CDTF0Menard, IL0.110
June 169:58 PM CDTF0Sangamon, IL0.110

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.