Tornadoes · United States · Oklahoma · 1965

F0 tornado, Grant County, Oklahoma, April 4, 1965

This F0 tornado ran 0.4 miles across Grant County on April 4, 1965, touching down at 8:00 PM GMT-6 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
April 4, 1965
Touchdown
8:00 PM GMT-6 (02:00 UTC)
Path length
0.4 miles (0.6 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Grant County
Touchdown point
36.680, -97.620
Record number
94

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.

Ok Cty/Will Rgrs, OK (KOKC), 00:00Z

2.0 hours before the tornado, 142 km from the path. April 5, 1965.

Skew-T log-pSkew-T log-p diagram, Ok Cty/Will Rgrs, OK at 00:00Z on 1965-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1873 joules per kilogram, CIN -26, lifted condensation level 762 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, Ok Cty/Will Rgrs, OK at 00:00Z on 1965-04-05The 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 168 square meters per square second, 0 to 6 km bulk shear 51 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
1873 J/kg
Mixed-layer CIN
-26 J/kg
Surface CAPE
2314 J/kg
Mixed-layer LCL
762 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
308 m²/s²
Significant tornado parameter
2.2
Supercell composite
9.3
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

Ok Cty/Will Rgrs, OK (KOKC), 12:00Z

10.0 hours after it, 142 km from the path. April 5, 1965.

Skew-T log-pSkew-T log-p diagram, Ok Cty/Will Rgrs, OK at 12:00Z on 1965-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 559 joules per kilogram, CIN -356, lifted condensation level 858 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, Ok Cty/Will Rgrs, OK at 12:00Z on 1965-04-05The 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 349 square meters per square second, 0 to 6 km bulk shear 51 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
559 J/kg
Mixed-layer CIN
-356 J/kg
Surface CAPE
923 J/kg
Mixed-layer LCL
858 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
47 kt
0-1 km storm-relative helicity
349 m²/s²
0-3 km storm-relative helicity
292 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1965 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of April 4, 1965

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 411:45 AM GMT-7F1Eddy, NM0.3167$500 to $5,000
April 45:10 PM GMT-6F2Washita, OK3.633
April 45:30 PM GMT-6F0Garfield, OK0.333$5,000 to $50,000
April 410:25 PM GMT-6F0Kay, OK0.110

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.