Tornadoes · United States · Wisconsin · 1979

F1 tornado, Eau Claire and Trempealeau counties, Wisconsin, June 16, 1979

This F1 tornado ran 17.6 miles across Eau Claire and Trempealeau counties on June 16, 1979, touching down at 4:00 PM CDT and reaching 100 yards wide. It killed nobody, 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 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, 1979
Touchdown
4:00 PM CDT (21:00 UTC)
Path length
17.6 miles (28.3 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Property damage
$500,000 to $5 million
Counties
Eau Claire and Trempealeau counties
Touchdown point
44.580, -91.470
Lift-off point
44.680, -91.120
Record number
345

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.

Minneapolis, MN (KSTC), 12:00Z

9.0 hours before the tornado, 184 km from the path. June 16, 1979.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 1979-06-16Temperature 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 -9837, lifted condensation level 2260 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, Minneapolis, MN at 12:00Z on 1979-06-16The 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 86 square meters per square second, 0 to 6 km bulk shear 41 knots.193958Sfc1 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
-9837 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2260 m above ground
0-6 km bulk shear
41 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4
0-3 km lapse rate
5.1 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KSTC), 00:00Z

3.0 hours after it, 184 km from the path. June 17, 1979.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 1979-06-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 6 joules per kilogram, CIN -7, lifted condensation level 607 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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, Minneapolis, MN at 00:00Z on 1979-06-17The 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 -129 square meters per square second, 0 to 6 km bulk shear 33 knots.193958Sfc1 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
6 J/kg
Mixed-layer CIN
-7 J/kg
Surface CAPE
15 J/kg
Mixed-layer LCL
607 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
-129 m²/s²
0-3 km storm-relative helicity
271 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

The surface observations

Eau Claire (EAU), 30 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:00 UTC6562350° 8 kt1007.5-RA
20:00 UTC6564350° 8 kt1006.8-RA
21:00 UTC6565360° 12 kt1005.8TSRA
21:15 UTC10° 15 kt1005.8
22:00 UTC6262350° 10 ktTS SHRA
22:10 UTC40° 14 kt1005.8

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

This ground now

The live radar over the trackEvery 1979 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

The other tornadoes of June 16, 1979

9 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 165:27 AM CDTF1McCook, SD0.110$5,000 to $50,000
June 166:15 AM CDTF1Pipestone, MN0.380$50,000 to $500,000
June 166:45 AM CDTF0Pipestone, MN0.150$5,000 to $50,000
June 1610:30 AM CDTF2Oconto, WI15.2100$50,000 to $500,000
June 164:30 PM CDTF1Lincoln, WI0.110$50,000 to $500,000
June 164:40 PM CDTF1Lincoln, WI0.110$50,000 to $500,000
June 167:46 PM MDTF0Laramie, WY0.160
June 167:50 PM MDTF2Cheyenne, CO3.0200$500,000 to $5 million
June 1612:30 AM CDTF1Graham, KS4.933$500,000 to $5 million

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.