Tornadoes · United States · Kansas · 1964

F1 tornado, Bourbon County, Kansas, April 12, 1964

This F1 tornado ran 4.3 miles across Bourbon County on April 12, 1964, touching down at 6:10 PM GMT-6 and reaching 77 yards wide. It killed nobody, and did $5,000 to $50,000 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
April 12, 1964
Touchdown
6:10 PM GMT-6 (00:10 UTC)
Path length
4.3 miles (6.9 km)
Path width
77 yards (70 m)
Deaths
0
Injuries
0
Property damage
$5,000 to $50,000
County
Bourbon County
Touchdown point
37.900, -94.770
Lift-off point
37.930, -94.700
Record number
98

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.

Topeka, KS (KTOP), 00:00Z

0.2 hours before the tornado, 144 km from the path. April 13, 1964.

Skew-T log-pSkew-T log-p diagram, Topeka, KS at 00:00Z on 1964-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 422 joules per kilogram, CIN -99, lifted condensation level 2092 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Topeka, KS at 00:00Z on 1964-04-13The 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 -68 square meters per square second, 0 to 6 km bulk shear 60 knots.1939587897Sfc1 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
422 J/kg
Mixed-layer CIN
-99 J/kg
Surface CAPE
1989 J/kg
Mixed-layer LCL
2092 m above ground
0-6 km bulk shear
60 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
-68 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.8
0-3 km lapse rate
7.6 K/km

Open this sounding in Storm Lab

Topeka, KS (KTOP), 12:00Z

11.8 hours after it, 144 km from the path. April 13, 1964.

Skew-T log-pSkew-T log-p diagram, Topeka, KS at 12:00Z on 1964-04-13Temperature 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 -17498, lifted condensation level 2206 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Topeka, KS at 12:00Z on 1964-04-13The 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 -247 square meters per square second, 0 to 6 km bulk shear 93 knots.1939587897117Sfc1 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
-17498 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2206 m above ground
0-6 km bulk shear
93 kt
0-1 km bulk shear
31 kt
0-1 km storm-relative helicity
-247 m²/s²
0-3 km storm-relative helicity
-121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1964 tornado in KansasEvery tornado in Kansas since 1950Warnings in force in Kansas nowThe forecast where you are

The other tornadoes of April 12, 1964

18 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 121:30 AM GMT-6F1Mississippi, AR0.110$500 to $5,000
April 123:26 PM GMT-6F3Douglas, KS33.88803$500,000 to $5 million
April 124:00 PM GMT-6F3Leavenworth, KS to MO14.0440122$500,000 to $5 million
April 124:00 PM GMT-6F4Anderson, KS19.488039$50,000 to $500,000
April 124:45 PM GMT-6F4Page, IA13.1400128$500,000 to $5 million
April 124:50 PM GMT-6F2Montgomery, IA2.0150$5,000 to $50,000
April 125:00 PM GMT-6F1Labette, KS3.6250$5,000 to $50,000
April 125:15 PM GMT-6F2Creek, OK0.250$500 to $5,000
April 125:30 PM GMT-6F1Cass, IA0.2200$5,000 to $50,000
April 125:30 PM GMT-6F2Union, IA9.410$50,000 to $500,000
April 125:45 PM GMT-6F1Clinton, MO6.250$500 to $5,000
April 126:00 PM GMT-6F3Cass, MO19.5100110$500,000 to $5 million
April 128:00 PM GMT-6F1Crawford, AR0.110$500 to $5,000
April 129:00 PM GMT-6F2Johnson, MO10.710013$50,000 to $500,000
April 1210:15 PM GMT-6F1Clark, AR0.5880$50,000 to $500,000
April 1210:15 PM GMT-6F1Clark, AR0.5880$50,000 to $500,000
April 1210:20 PM GMT-6F2Nodaway, MO10.880$500,000 to $5 million
April 1211:20 PM GMT-6F1Jackson, AR0.110$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.