Tornadoes · United States · Oklahoma · 1974

F3 tornado, Grady, Canadian, Oklahoma and Lincoln counties, Oklahoma, April 20, 1974

This F3 tornado ran 63.6 miles across Grady, Canadian, Oklahoma and Lincoln counties on April 20, 1974, touching down at 4:00 PM CDT and reaching 100 yards wide. It killed nobody and injured 3, and did $500,000 to $5 million 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 20, 1974
Touchdown
4:00 PM CDT (21:00 UTC)
Path length
63.6 miles (102.3 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
3
Property damage
$500,000 to $5 million
Counties
Grady, Canadian, Oklahoma and Lincoln counties
Touchdown point
35.270, -97.930
Lift-off point
35.630, -96.900
Record number
310

The surface observations

Tinker Afb (TIK), 5 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:00 UTC6660180° 18 kt231007.1
20:00 UTC6860190° 20 kt271006.8
21:00 UTC6860180° 16 kt221006.1
22:00 UTC6658240° 20 kt381006.1TSPL

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

This ground now

The live radar over the trackEvery 1974 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of April 20, 1974

13 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 201:05 AM CDTF0Kingman, KS41.333under $50
April 2010:30 AM CDTF0Harper, KS0.317under $50
April 203:10 PM CDTF3Buffalo, NE63.58806$500,000 to $5 million
April 203:30 PM CDTF1Buffalo, NE1.210$5,000 to $50,000
April 204:05 PM CDTF2Sherman, NE46.810$5,000 to $50,000
April 204:15 PM CDTF1Reno, KS14.01003$5,000 to $50,000
April 204:30 PM CDTF3Nuckolls, NE41.610$5,000 to $50,000
April 205:30 PM CDTF2Anderson, KS1.0200$5,000 to $50,000
April 205:30 PM CDTF1Buffalo, NE0.110$500 to $5,000
April 205:30 PM CDTF1Wichita, TX0.5100$50 to $500
April 205:33 PM CDTF3Jefferson, OK6.1100$50,000 to $500,000
April 206:00 PM CDTF1Holt, NE0.110$500 to $5,000
April 206:07 PM CDTF1Hand, SD0.510

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.