Tornadoes · United States · Texas · 1966

F3 tornado, Karnes County, Texas, April 25, 1966

This F3 tornado ran 0.1 miles across Karnes County on April 25, 1966, touching down at 1:15 AM GMT-5 and reaching 100 yards wide. It killed nobody and injured 3, and did $50,000 to $500,000 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 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 mphthis tornado

    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
F3
Date
April 25, 1966
Touchdown
1:15 AM GMT-5 (06:15 UTC)
Path length
0.1 miles (0.2 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
3
Property damage
$50,000 to $500,000
County
Karnes County
Touchdown point
28.820, -97.870
Lift-off point
28.820, -97.870
Record number
95

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), 00:00Z

6.3 hours before the tornado, 94 km from the path. April 25, 1966.

Skew-T log-pSkew-T log-p diagram, San Antonio Intl, TX at 00:00Z on 1966-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1732 joules per kilogram, CIN -1, lifted condensation level 669 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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, San Antonio Intl, TX at 00:00Z on 1966-04-25The 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 71 square meters per square second, 0 to 6 km bulk shear 65 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
1732 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
2880 J/kg
Mixed-layer LCL
669 m above ground
0-6 km bulk shear
65 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.0
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

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

5.7 hours after it, 94 km from the path. April 25, 1966.

Skew-T log-pSkew-T log-p diagram, San Antonio Intl, TX at 12:00Z on 1966-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 170 joules per kilogram, CIN -110, lifted condensation level 632 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, San Antonio Intl, TX at 12:00Z on 1966-04-25The 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 21 square meters per square second, 0 to 6 km bulk shear 78 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
170 J/kg
Mixed-layer CIN
-110 J/kg
Surface CAPE
126 J/kg
Mixed-layer LCL
632 m above ground
0-6 km bulk shear
78 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1966 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of April 25, 1966

3 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 255:30 PM GMT-5F1Harrison, TX8.333$500 to $5,000
April 256:30 PM GMT-5F1Wood, TX2.027$500 to $5,000
April 259:05 PM GMT-5F1Marion, TX0.123

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.