Tornadoes · United States · Texas · 1968

F1 tornado, Cameron County, Texas, June 20, 1968

This F1 tornado ran 0.2 miles across Cameron County on June 20, 1968, touching down at 3:05 PM GMT-5 and reaching 17 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 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 20, 1968
Touchdown
3:05 PM GMT-5 (20:05 UTC)
Path length
0.2 miles (0.3 km)
Path width
17 yards (16 m)
Deaths
0
Injuries
0
County
Cameron County
Touchdown point
26.130, -97.780
Record number
362

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.

Brownsville Intl, TX (KBRO), 12:00Z

8.1 hours before the tornado, 46 km from the path. June 20, 1968.

Skew-T log-pSkew-T log-p diagram, Brownsville Intl, TX at 12:00Z on 1968-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 981 joules per kilogram, CIN -19, lifted condensation level 808 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, Brownsville Intl, TX at 12:00Z on 1968-06-20The 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 15 square meters per square second, 0 to 6 km bulk shear 11 knots.1939Sfc1 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
981 J/kg
Mixed-layer CIN
-19 J/kg
Surface CAPE
775 J/kg
Mixed-layer LCL
808 m above ground
0-6 km bulk shear
11 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Brownsville Intl, TX (KBRO), 00:00Z

3.9 hours after it, 46 km from the path. June 21, 1968.

Skew-T log-pSkew-T log-p diagram, Brownsville Intl, TX at 00:00Z on 1968-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1034 joules per kilogram, CIN -55, lifted condensation level 1036 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, Brownsville Intl, TX at 00:00Z on 1968-06-21The 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 18 square meters per square second, 0 to 6 km bulk shear 24 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
1034 J/kg
Mixed-layer CIN
-55 J/kg
Surface CAPE
3068 J/kg
Mixed-layer LCL
1036 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

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 June 20, 1968

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 2012:20 PM GMT-5F1Plaquemines Parish, LA0.5100$5,000 to $50,000
June 207:00 PM GMT-6F2Perkins, SD0.110
June 208:00 PM GMT-6F2Lawrence, SD13.1100
June 209:05 PM GMT-5F1Rice, MN0.110$5,000 to $50,000
June 2011:00 PM GMT-5F3Walworth, SD8.8200
June 2011:00 PM GMT-5F3Walworth, SD0.110
June 2011:30 PM GMT-5F2Gregory, SD33.510
June 2010:30 PM GMT-6F2Stanley, SD0.110
June 2011:45 PM GMT-5F2Aurora, SD21.410
June 2012:00 AM GMT-5F3Davison, SD9.92,667
June 2012:10 AM GMT-5F0Winona, MN0.110$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.