Tornadoes · United States · Texas · 1968

F0 tornado, Gray and Roberts counties, Texas, May 6, 1968

This F0 tornado ran 12.3 miles across Gray and Roberts counties on May 6, 1968, touching down at 2:10 PM GMT-5 and reaching 100 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
May 6, 1968
Touchdown
2:10 PM GMT-5 (19:10 UTC)
Path length
12.3 miles (19.8 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Counties
Gray and Roberts counties
Touchdown point
35.550, -100.800
Lift-off point
35.670, -100.630
Record number
147

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.

Amarillo Airport, TX (KAMA), 12:00Z

7.2 hours before the tornado, 99 km from the path. May 6, 1968.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 12:00Z on 1968-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 635 joules per kilogram, CIN -6, lifted condensation level 655 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, Amarillo Airport, TX at 12:00Z on 1968-05-06The 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 177 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
635 J/kg
Mixed-layer CIN
-6 J/kg
Surface CAPE
569 J/kg
Mixed-layer LCL
655 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
177 m²/s²
0-3 km storm-relative helicity
212 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.0
0-3 km lapse rate
6.5 K/km

Open this sounding in Storm Lab

Amarillo Airport, TX (KAMA), 00:00Z

4.8 hours after it, 99 km from the path. May 7, 1968.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 00:00Z on 1968-05-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 166 joules per kilogram, CIN -2, lifted condensation level 3313 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, Amarillo Airport, TX at 00:00Z on 1968-05-07The 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 42 square meters per square second, 0 to 6 km bulk shear 22 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
166 J/kg
Mixed-layer CIN
-2 J/kg
Surface CAPE
296 J/kg
Mixed-layer LCL
3313 m above ground
0-6 km bulk shear
22 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
9.7 K/km

Open this sounding in Storm Lab

The surface observations

Amarillo - Rick Husband Intl (AMA), 100 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:00 UTC7453210° 20 kt1001.7
19:00 UTC7750200° 20 kt1000.7
20:00 UTC8149210° 15 kt998.6
21:00 UTC8141260° 23 kt997.6

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

This ground now

The live radar over the trackEvery 1968 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of May 6, 1968

6 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 62:10 PM GMT-5F0Gray, TX12.3100
May 65:05 PM GMT-5F3Roberts, TX0.51006$500,000 to $5 million
May 66:15 PM GMT-5F2Harmon, OK4.710$50,000 to $500,000
May 68:30 PM GMT-5F1Harmon, OK0.110
May 68:44 PM GMT-5F1Greer, OK0.110
May 610:25 PM GMT-6F0Chase, NE0.110

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.