Tornadoes · United States · Iowa · 1984

F0 tornado, Jones County, Iowa, June 22, 1984

This F0 tornado ran 0.1 miles across Jones County on June 22, 1984, touching down at 9:15 PM CDT and reaching 10 yards wide. It killed nobody.

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 mphthis tornado

    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 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
F0
Date
June 22, 1984
Touchdown
9:15 PM CDT (02:15 UTC)
Path length
0.1 miles (0.2 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Jones County
Touchdown point
42.080, -91.270
Record number
667

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.

Peoria Regional, IL (KPIA), 00:00Z

2.3 hours before the tornado, 210 km from the path. June 23, 1984.

Skew-T log-pSkew-T log-p diagram, Peoria Regional, IL at 00:00Z on 1984-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1818 joules per kilogram, CIN -12, lifted condensation level 1424 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, Peoria Regional, IL at 00:00Z on 1984-06-23The 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 28 square meters per square second, 0 to 6 km bulk shear 36 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
1818 J/kg
Mixed-layer CIN
-12 J/kg
Surface CAPE
3274 J/kg
Mixed-layer LCL
1424 m above ground
0-6 km bulk shear
36 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
80 m²/s²
Significant tornado parameter
0.3
Supercell composite
4.7
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

Peoria Regional, IL (KPIA), 12:00Z

9.7 hours after it, 210 km from the path. June 23, 1984.

Skew-T log-pSkew-T log-p diagram, Peoria Regional, IL at 12:00Z on 1984-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 50 joules per kilogram, CIN -222, lifted condensation level 1105 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, Peoria Regional, IL at 12:00Z on 1984-06-23The 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 130 square meters per square second, 0 to 6 km bulk shear 14 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
50 J/kg
Mixed-layer CIN
-222 J/kg
Surface CAPE
79 J/kg
Mixed-layer LCL
1105 m above ground
0-6 km bulk shear
14 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
178 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

The surface observations

Cedar Rapids (CID), 44 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
01:00 UTC817150° 3 kt1010.2
01:25 UTC300° 20 kt251011.5
02:00 UTC6866320° 20 kt251011.9TSRA FG
03:00 UTC6866360° 14 kt1011.5TSRA
04:00 UTC6866360° 15 kt1011.5

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

This ground now

The live radar over the trackEvery 1984 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of June 22, 1984

21 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 2210:56 AM CDTF0Green, WI1.050$500 to $5,000
June 221:30 PM CDTF1Boone, IL0.6200$5,000 to $50,000
June 223:40 PM CDTF1Bottineau, ND2.520$5,000 to $50,000
June 223:45 PM CDTF0Sedgwick, KS0.850
June 223:55 PM CDTF0Sedgwick, KS0.110
June 225:10 PM CDTF0Ellis, KS0.110
June 225:45 PM CDTF0Jerauld, SD0.110
June 226:45 PM CDTF1Cerro Gordo, IA15.077$500,000 to $5 million
June 226:58 PM CDTF0Douglas, SD0.110
June 227:02 PM CDTF0Floyd, IA0.110
June 227:12 PM CDTF0Story, IA0.110
June 227:15 PM CDTF0Douglas, SD7.010
June 227:15 PM CDTF0Douglas, SD0.110
June 227:15 PM CDTF0Butler, IA0.110
June 227:30 PM CDTF0Hand, SD0.110
June 227:55 PM CDTF1Vermilion, IL1.0300$50,000 to $500,000
June 228:00 PM CDTF0Bon Homme, SD0.110
June 228:22 PM CDTF0Benton, IA0.110
June 229:00 PM CDTF0Knox, NE1.020
June 229:55 PM CDTF0Cedar, IA0.110
June 2211:00 PM MDTF0Goshen, WY0.510$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.