Tornadoes · United States · Texas · 1964

F2 tornado, Williamson County, Texas, April 26, 1964

This F2 tornado ran 1.0 miles across Williamson County on April 26, 1964, touching down at 7:00 AM GMT-5 and reaching 17 yards wide. It killed nobody, and did $500 to $5,000 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 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mphthis tornado

    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
F2
Date
April 26, 1964
Touchdown
7:00 AM GMT-5 (12:00 UTC)
Path length
1.0 miles (1.6 km)
Path width
17 yards (16 m)
Deaths
0
Injuries
0
Property damage
$500 to $5,000
County
Williamson County
Touchdown point
30.550, -97.700
Record number
175

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.

San Antonio Intl, TX (KSAT), 12:00Z

0.0 hours before the tornado, 132 km from the path. April 26, 1964.

Skew-T log-pSkew-T log-p diagram, San Antonio Intl, TX at 12:00Z on 1964-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1886 joules per kilogram, CIN -7, lifted condensation level 733 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, San Antonio Intl, TX at 12:00Z on 1964-04-26The 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 145 square meters per square second, 0 to 6 km bulk shear 62 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
1886 J/kg
Mixed-layer CIN
-7 J/kg
Surface CAPE
2765 J/kg
Mixed-layer LCL
733 m above ground
0-6 km bulk shear
62 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
129 m²/s²
Significant tornado parameter
1.6
Supercell composite
6.9
0-3 km lapse rate
5.8 K/km

Open this sounding in Storm Lab

San Antonio Intl, TX (KSAT), 00:00Z

12.0 hours after it, 132 km from the path. April 27, 1964.

Skew-T log-pSkew-T log-p diagram, San Antonio Intl, TX at 00:00Z on 1964-04-27Temperature 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 -10159, lifted condensation level 3163 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, San Antonio Intl, TX at 00:00Z on 1964-04-27The 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 69 knots.1939587897117136Sfc1 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
-10159 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
3163 m above ground
0-6 km bulk shear
69 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
-39 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
8.3 K/km

Open this sounding in Storm Lab

The surface observations

Austin - City/Camp Mabry (ATT), 26 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
10:00 UTC7370160° 7 kt1000.7FG
11:00 UTC7370150° 4 kt1000.3FG
12:00 UTC6562320° 15 kt1003.4SHRA FG
13:00 UTC6461240° 10 kt1003.4TSRA FG

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

This ground now

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

The other tornadoes of April 26, 1964

16 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 2611:20 AM GMT-5F1Neosho, KS0.110$50 to $500
April 2611:30 AM GMT-5F0Shelby, TX1.017$5,000 to $50,000
April 2611:30 AM GMT-5F2Shelby, TX1.933$5,000 to $50,000
April 2611:30 AM GMT-5F0Shelby, TX0.213$5,000 to $50,000
April 2612:30 PM GMT-5F2Buffalo, NE9.510$5,000 to $50,000
April 261:30 PM GMT-5F1Custer, NE0.110$5,000 to $50,000
April 263:00 PM GMT-5F2Antelope, NE26.410$50,000 to $500,000
April 264:45 PM GMT-5F1Linn, KS0.110$50 to $500
April 267:25 PM GMT-5F0Franklin, KS0.110
April 268:10 PM GMT-5F2Union, IA14.8300$5,000 to $50,000
April 268:30 PM GMT-5F0Johnson, KS0.110
April 268:40 PM GMT-5F0Johnson, KS0.110
April 268:50 PM GMT-5F0Johnson, KS0.110
April 269:00 PM GMT-5F0Howard, AR0.110
April 2612:00 AM GMT-5F2Van Buren, IA2.0200$5,000 to $50,000
April 2612:30 AM GMT-5F2Wright, IA4.7300$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.