Tornadoes · United States · Iowa · 1969

F0 tornado, Warren County, Iowa, June 22, 1969

This F0 tornado ran 0.1 miles across Warren County on June 22, 1969, touching down at 4:35 PM GMT-5 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, estimated from the damage record rather than surveyed
Date
June 22, 1969
Touchdown
4:35 PM GMT-5 (21:35 UTC)
Path length
0.1 miles (0.2 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Warren County
Touchdown point
41.400, -93.600
Record number
290

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.

Omaha, NE (KOAX), 12:00Z

9.6 hours before the tornado, 231 km from the path. June 22, 1969.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 1969-06-22Temperature 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 -42946, lifted condensation level 3634 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, Omaha, NE at 12:00Z on 1969-06-22The 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 -39 square meters per square second, 0 to 6 km bulk shear 45 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
-42946 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
3634 m above ground
0-6 km bulk shear
45 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
-39 m²/s²
0-3 km storm-relative helicity
-36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

Omaha, NE (KOAX), 00:00Z

2.4 hours after it, 231 km from the path. June 23, 1969.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 1969-06-23Temperature 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 -84413, lifted condensation level 3631 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, Omaha, NE at 00:00Z on 1969-06-23The 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 -5 square meters per square second, 0 to 6 km bulk shear 27 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
-84413 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
3631 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
2 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.1 K/km

Open this sounding in Storm Lab

The surface observations

Des Moines (DSM), 16 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:00 UTC7466160° 5 kt
21:00 UTC706650° 7 kt1001TSRA
22:00 UTC727060° 7 ktFZFG
23:00 UTC72680° 0 ktFZFG

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

This ground now

The live radar over the trackEvery 1969 tornado in IowaEvery tornado in Iowa since 1950Warnings in force in Iowa nowThe forecast where you are

The other tornadoes of June 22, 1969

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 222:00 AM GMT-5F2Furnas, NE4.1101$5,000 to $50,000
June 222:00 AM GMT-5F1Platte, MO0.350$5,000 to $50,000
June 224:00 AM GMT-5F1Nance, NE0.110$5,000 to $50,000
June 226:30 AM GMT-5F1Platte, NE0.110
June 224:40 PM GMT-5F1Warren, IA0.110$5,000 to $50,000
June 225:25 PM GMT-5F0Marshall, IA1.0200$5,000 to $50,000
June 225:30 PM GMT-5F0Cedar, MO0.310under $50
June 226:40 PM GMT-5F4Washington, MO20.2800222$500,000 to $5 million
June 227:35 PM GMT-5F4Saint Francois, MO15.1440414$500,000 to $5 million
June 228:15 PM GMT-5F3Perry, MO18.11006$50,000 to $500,000
June 229:30 PM GMT-5F2Lincoln, OK0.110$500 to $5,000

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.