Tornadoes · United States · Nebraska · 2021
EF2 tornado, Avoca, Nebraska, December 15, 2021
This EF2 tornado ran 3.3 miles across Cass County on December 15, 2021, touching down at 3:55 PM CST and reaching 20 yards wide. It killed nobody.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 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.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 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.
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
- EF2
- Date
- December 15, 2021
- Touchdown
- 3:55 PM CST (21:55 UTC)
- Lifted
- 3:59 PM CST (21:59 UTC)
- On the ground
- 4 minutes
- Path length
- 3.3 miles (5.3 km)
- Path width
- 20 yards (18 m)
- Deaths
- 0
- Injuries
- 0
- County
- Cass County
- Touchdown point
- 40.636, -96.159
- Lift-off point
- 40.660, -96.130
- Record number
- 2112151555-01
The damage survey
17 damage points were recorded along this path by NWS OAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 113 mph.
- Western edge of downed wood power poles
- Numerous pine trees destroyed. Tree fell on house. Damaged roof. Minor roof damage to other outbuildings
- 5 downed poles. Snapped, broken off at base. Eastern edge of downed power poles and power lines
- Collapse and roof uplift of several farm outbuildings per Otoe EMA. Lines up well with narrow damage track further north & east
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
What the Weather Service recorded
A low pressure system brought strong (both thunderstorm, and non-thunderstorm) winds, tornadoes, dust, snow, and record temperatures into eastern Nebraska and western Iowa. The event was determined to be a derecho meeting the criteria of wind damage extending more than 250 miles, including wind gusts of at least 58 mph and numerous gusts of at least 75 mph.
A very narrow tornado was witnessed and caused substantial damage to vehicles and farm equipment while destroying a large shed near its onset and proceeded to cause minor damage for approximately 3 miles to the northeast before dissipating.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.
The county was under a tornado watch, issued at 19:23 UTC and running to 23:19 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 15:00 UTC | 08:20 UTC | High Wind Watch | OAX |
| 18:00 UTC | 00:25 UTC | Red Flag Warning | OAX |
| 18:00 UTC | 03:00 UTC | High Wind Warning | OAX |
| 18:00 UTC | 20:21 UTC | Fire Weather Watch | OAX |
| 19:23 UTC | 23:19 UTC | Tornado Watch | OAX |
| 20:54 UTC | 22:15 UTC | Severe Thunderstorm Warning | OAX |
| 21:35 UTC | 22:45 UTC | Severe Thunderstorm Warning | OAX |
| 22:01 UTC | 22:10 UTC | Tornado Warning | OAX |
| 23:08 UTC | 03:00 UTC | Blowing Dust Advisory | OAX |
| 03:00 UTC | 06:00 UTC | Wind Advisory | OAX |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:28 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
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.
Omaha, NE (KOAX), 12:00Z
9.9 hours before the tornado, 77 km from the path. December 15, 2021.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -103670 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 2165 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 346 m²/s²
- 0-3 km storm-relative helicity
- 384 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 3.2 K/km
Omaha, NE (KOAX), 00:00Z
2.1 hours after it, 77 km from the path. December 16, 2021.
- Mixed-layer CAPE
- 4 J/kg
- Mixed-layer CIN
- -66 J/kg
- Surface CAPE
- 69 J/kg
- Mixed-layer LCL
- 1685 m above ground
- 0-6 km bulk shear
- 103 kt
- 0-1 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- -450 m²/s²
- 0-3 km storm-relative helicity
- -705 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 6.4 K/km
The surface observations
Nebraska City (AFK), 24 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 19:55 UTC | 73.8 | 56.7 | 200° 33 kt | 47 | 995.6 | |
| 20:15 UTC | 73 | 56.7 | 190° 32 kt | 40 | 994.6 | |
| 20:35 UTC | 73.8 | 56.8 | 190° 36 kt | 47 | 993.2 | |
| 20:55 UTC | 73 | 57.2 | 190° 34 kt | 42 | 992.2 | |
| 21:15 UTC | 71.8 | 56.8 | 190° 25 kt | 43 | 991.2 | |
| 21:35 UTC | 71.6 | 56.8 | 190° 32 kt | 40 | 990.2 | |
| 21:55 UTC | 71.6 | 56.5 | 170° 33 kt | 46 | 989.2 | |
| 22:15 UTC | 55 | 47 | 240° 42 kt | 992.2 | VCTS | |
| 22:35 UTC | 52 | 49 | 220° 28 kt | 39 | 991.2 | -TSRA |
| 22:55 UTC | 54.3 | 49.3 | 210° 18 kt | 30 | 991.5 | HZ |
| 23:15 UTC | 57.4 | 47 | 220° 20 kt | 31 | 990.9 | HZ |
| 23:35 UTC | 60 | 41 | 210° 24 kt | 31 | 990.5 | HZ |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Omaha radar (KOAX), 77 km away, was scanning. The volume nearest the touchdown began at 21:55 UTC.
Open the radar archive at this moment, over the track
Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 21:21 UTC | TSTM WND GST 67 | 3 Ese Lincoln | Lancaster, NE | FROM A PERSONAL WEATHER STATION. |
| 21:29 UTC | NON-TSTM WND GST 93 | 5 Wnw Lincoln | Lancaster, NE | ASOS STATION KLNK LINCOLN AIRPORT. |
| 21:30 UTC | TSTM WND GST 93 | 4 Nw Lincoln | Lancaster, NE | |
| 21:32 UTC | TSTM WND DMG | 1 Nnw Hickman | Lancaster, NE | DELAYED REPORT, TIME ESTIMATED FROM RADAR. REPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN. |
| 21:37 UTC | TSTM WND DMG | 2 Ene Davey | Lancaster, NE | DELAYED REPORT, TIME ESTIMATED FROM RADAR. SEVERAL LARGE TREES SNAPPED OR UPROOTED. NO DAMAGE TO BUILDINGS AT THE RESIDENCE. |
| 21:38 UTC | NON-TSTM WND GST 57 | 1 Ene Lincoln | Lancaster, NE | MESONET STATION FW4554 LINCOLN. |
| 21:40 UTC | TSTM WND DMG | 5 N Lincoln | Lancaster, NE | REPORT OF ROOF BLOWN OFF APARTMENT BUILDING. |
| 21:40 UTC | TSTM WND DMG | Denton | Lancaster, NE | ALMOST 20' TREE BLOWN OVER AND PATIO FURNITURE TOSSED AROUND NEAR DENTON. |
| 21:41 UTC | TSTM WND DMG | 3 E Ceresco | Saunders, NE | DELAYED REPORT, TIME ESTIMATED FROM RADAR. REPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN. |
| 21:41 UTC | TORNADO | 4 E Ceresco | Saunders, NE | A TORNADO DEVELOPED JUST NORTH OF THE JACK SINN MEMORIAL WILDLIFE MANAGEMENT AREA, PRODUCING DAMAGE TO FARM BUILDINGS AND THEN MOVING OFF TOWARD THE NORTHEAST, AND EVENTUALLY THE NORTH NORTHEAST AS OBSERVED BY A STORM CH |
| 21:44 UTC | TSTM WND GST 92 | Bennet | Lancaster, NE | |
| 21:44 UTC | TORNADO | 4 E Ceresco | Saunders, NE | GENERAL TRACK BEGINNING NEAR CO RD 14 & CO RD A AND TRACK ENDED NEAR CO RD 11 & CO RD E. |
| 21:46 UTC | TSTM WND DMG | 3 Sw Douglas | Otoe, NE | DELAYED REPORT, TIME ESTIMATED FROM RADAR. REPORT FROM MPING: TREES UPROOTED OR SNAPPED; ROOF BLOWN OFF. |
| 21:49 UTC | TSTM WND GST 90 | Eagle | Cass, NE | |
| 21:55 UTC | TORNADO | 2 Wsw Avoca | Otoe, NE | A VERY NARROW TORNADO, APPROXIMATELY 20 YARDS WIDE, WAS WITNESSED AND CAUSED SUBSTANTIAL DAMAGE TO VEHICLES AND FARM EQUIPMENT WHILE DESTROYING A LARGE SHED NEAR ITS ONSET AND PROCEEDED TO CAUSE MINOR DAMAGE FOR APPROXIM |
| 21:56 UTC | TSTM WND GST 70 | 3 Wnw Otoe | Otoe, NE | |
| 21:56 UTC | TSTM WND GST 70 | 3 W Otoe | Otoe, NE | |
| 21:57 UTC | TSTM WND GST 81 | 3 Ese Lewiston | Pawnee, NE | |
| 22:01 UTC | TSTM WND DMG | 3 Ene Lincoln | Lancaster, NE | REPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN. |
| 22:01 UTC | TSTM WND DMG | 5 Ssw Union | Otoe, NE | BARN AND GRAIN BINS DESTROYED. TREES SNAPPED. ADDITIONAL DAMAGE TO TREES AND POWER LINES ACROSS OTHER PARTS OF OTOE COUNTY AS WELL. |
| 22:05 UTC | NON-TSTM WND GST 48 | 3 Nw Nebraska City | Otoe, NE | MESONET STATION NB047 NEBRASKA CITY 3NW. |
| 22:05 UTC | TORNADO | 3 Ne Nehawka | Cass, NE | ROOF REMOVED FROM HOUSE. ROOF OVER GARAGE UPLIFTED AND DISPLACED. HOUSE MOVED SLIGHTLY ON FOUNDATION. SEVERAL LARGE PINES & OAK TREES SNAPPED. |
| 22:05 UTC | TORNADO | 4 S Union | Otoe, NE | A BRIEF EF-1 TORNADO SNAPPED POWER POLES. SWIRLING WAS NOTED IN CORN FIELDS NORTH AND SOUTH OF COUNTY ROAD C. |
| 22:05 UTC | TORNADO | 4 S Union | Otoe, NE | A BRIEF EF-1 TORNADO SNAPPED POWER POLES. SWIRLING WAS NOTED IN CORN FIELDS NORTH AND SOUTH OF COUNTY ROAD C. |
| 22:06 UTC | TORNADO | 2 Sse Murray | Cass, NE | A BRIEF EF-1 TORNADO CAUSED DAMAGE TO POWER POLES AND TOTAL DESTRUCTION OF A FARM OUTBUILDING NEAR HIGHWAY 75 AND BAXTER LOOP. |
| 22:06 UTC | TORNADO | 3 Ne Nehawka | Cass, NE | CORRECTS PREVIOUS TORNADO REPORT FROM 3 NE NEHAWKA. TORNADO TRACK COMBINED WITH PREVIOUSLY SEPARATE TRACK THAT STARTED 2 SSE OF MURRAY, OR 3 SW OF BEAVER LAKE. TORNADO REMOVED ROOF FROM HOUSE. ROOF OVER GARAGE UPLIFTED A |
| 22:07 UTC | TORNADO | 3 E Pawnee City | Pawnee, NE | A BRIEF TORNADO DESTROYED SEVERAL OUTBUILDINGS AND REMOVED A WRAP-AROUND PORCH FROM A HOUSE. |
| 22:08 UTC | TSTM WND DMG | 2 Ene Murray | Cass, NE | ROOF BLOWN AWAY AT BEAVER LAKE. |
| 22:09 UTC | TORNADO | 3 E Murray | Cass, NE | THREE WITNESSES OBSERVED TORNADO FORM SOUTH SIDE OF LAKE. ROOF TAKEN OFF RESIDENCE. SEVERAL HARDWOOD TREES SNAPPED AND PINE TREES UPROOTED OR SNAPPED. |
| 22:10 UTC | TSTM WND DMG | Pawnee City | Pawnee, NE | LOTS OF STRUCTURE DAMAGE, ROOF DAMAGE, CARPORTS DAMAGED. |
| 22:10 UTC | TORNADO | 3 E Murray | Cass, NE | CORRECTS PREVIOUS TORNADO REPORT FROM 3 E MURRAY. TORNADO TRACK COMBINED WITH PREVIOUSLY SEPARATE TORNADO TRACK THAT BEGAN 4 ENE MURRAY, OR 2 NE BEAVER LAKE. THREE WITNESSES OBSERVED TORNADO FORM SOUTH SIDE OF BEAVER LAK |
| 22:10 UTC | TORNADO | 4 Ene Murray | Cass, NE | TORNADO DEVELOPED IN OPEN FIELD AND TRAVELED NORTH-NORTHEAST. SUBSTANTIAL DAMAGE WAS DONE TO A HORSE FARM. EXTENSION OF HOUSE DESTROYED. HORSE TRAILER ROLLED. SEVERAL LARGE TREES SNAPPED AN UPROOTED. UNABLE TO SURVEY NOR |
| 22:13 UTC | TSTM WND DMG | Bellevue | Sarpy, NE | NUMEROUS LARGE TREES DOWN AND HOMES DAMAGED. |
| 22:14 UTC | TSTM WND GST 62 | 2 S Murray | Cass, NE | MESONET STATION UP945 2.2 S MURRAY (UPR). |
| 22:14 UTC | NON-TSTM WND GST 81 | Offutt Afb | Sarpy, NE | AWOS STATION KOFF OFFUTT AFB. |
| 22:15 UTC | TSTM WND DMG | Auburn | Nemaha, NE | DELAYED REPORT, TIME ESTIMATED FROM RADAR. REPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN. |
| 22:16 UTC | TSTM WND DMG | Bellevue | Sarpy, NE | LARGE LIMB CRUSHED CAR. FENCE DOWN. |
| 22:16 UTC | NON-TSTM WND GST 50 | Springfield | Sarpy, NE | MESONET STATION EW9007 SPRINGFIELD. |
| 22:16 UTC | NON-TSTM WND GST 52 | 3 Sse Plattsmouth | Cass, NE | MESONET STATION FW9521 PLATTSMOUTH. |
| 22:22 UTC | TSTM WND GST 81 | Offutt Afb | Sarpy, NE |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2021 tornado in NebraskaEvery tornado in Nebraska since 1950Warnings in force in Nebraska nowThe forecast where you are
The other tornadoes of December 15, 2021
124 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| December 15 | 1:27 PM CST | EF0 | Kearney, NE | 11.0 | 150 | $700,000 | ||
| December 15 | 1:29 PM CST | EF0 | Franklin, NE | 13.4 | 100 | $700,000 | ||
| December 15 | 1:33 PM CST | EF0 | Kearney, NE | 7.1 | 120 | $350,000 | ||
| December 15 | 1:44 PM CST | EF1 | Webster, NE | 14.8 | 180 | $400,000 | ||
| December 15 | 1:53 PM CST | EF1 | Adams, NE | 8.6 | 150 | $400,000 | ||
| December 15 | 2:03 PM CST | EF0 | Adams, NE | 7.2 | 60 | $302,000 | ||
| December 15 | 2:11 PM CST | EF1 | Hamilton, NE | 12.9 | 400 | $500,000 | ||
| December 15 | 2:26 PM CST | EF1 | Hamilton, NE | 12.0 | 400 | $500,000 | ||
| December 15 | 2:35 PM CST | EF1 | Polk, NE | 7.5 | 350 | $400,000 | ||
| December 15 | 3:03 PM CST | EF1 | Platte, NE | 0.8 | 30 | |||
| December 15 | 3:04 PM CST | EF2 | Platte, NE | 2.7 | 50 | 2 | ||
| December 15 | 3:11 PM CST | EF2 | Saline, NE | 23.7 | 70 | |||
| December 15 | 3:27 PM CST | EF1 | Colfax, NE | 1.5 | 30 | |||
| December 15 | 3:31 PM CST | EF2 | Cuming, NE | 6.3 | 100 | |||
| December 15 | 3:37 PM CST | EF1 | Cuming, NE | 4.8 | 50 | |||
| December 15 | 3:37 PM CST | EF1 | Cuming, NE | 1.8 | 50 | |||
| December 15 | 3:41 PM CST | EF1 | Cuming, NE | 0.4 | 50 | |||
| December 15 | 3:41 PM CST | EF1 | Saunders, NE | 16.6 | 100 | |||
| December 15 | 3:44 PM CST | EF2 | Cuming, NE | 11.2 | 200 | |||
| December 15 | 3:46 PM CST | EF1 | Saunders, NE | 0.7 | 100 | |||
| December 15 | 3:51 PM CST | EF1 | Cuming, NE | 11.2 | 20 | |||
| December 15 | 4:05 PM CST | EF1 | Otoe, NE | 0.1 | 200 | |||
| December 15 | 4:05 PM CST | EF1 | Pawnee, NE | 0.2 | 20 | |||
| December 15 | 4:06 PM CST | EF0 | Pawnee, NE | 2.2 | 20 | |||
| December 15 | 4:06 PM CST | EF2 | Cass, NE | 3.6 | 150 | |||
| December 15 | 4:07 PM CST | EF1 | Pawnee, NE | 0.8 | 100 | |||
| December 15 | 4:09 PM CST | EF2 | Cass, NE | 2.6 | 200 | |||
| December 15 | 4:14 PM CST | EF1 | Mills, IA | 10.0 | 100 | |||
| December 15 | 4:15 PM CST | Unrated | Woodbury, IA | 0.8 | 20 | |||
| December 15 | 4:16 PM CST | EF0 | Pottawattamie, IA | 0.9 | 30 | |||
| December 15 | 4:20 PM CST | EF1 | Woodbury, IA | 4.6 | 75 | $250,000 | ||
| December 15 | 4:24 PM CST | EF2 | Pottawattamie, IA | 2.3 | 50 | |||
| December 15 | 4:25 PM CST | EF2 | Woodbury, IA | 8.4 | 100 | $500,000 | ||
| December 15 | 4:31 PM CST | EF1 | Mills, IA | 0.6 | 50 | |||
| December 15 | 4:31 PM CST | EF2 | Pottawattamie, IA | 6.7 | 75 | |||
| December 15 | 4:34 PM CST | EF1 | Pottawattamie, IA | 9.6 | 50 | |||
| December 15 | 4:35 PM CST | EF1 | Woodbury, IA | 4.3 | 75 | $200,000 | ||
| December 15 | 4:39 PM CST | EF1 | Plymouth, IA | 3.7 | 75 | $50,000 | ||
| December 15 | 4:42 PM CST | EF1 | Ida, IA | 13.0 | 75 | $200,000 | ||
| December 15 | 4:48 PM CST | Unrated | Crawford, IA | 4.4 | 50 | |||
| December 15 | 4:49 PM CST | EF2 | Cass, IA | 27.1 | 100 | $350,000 | ||
| December 15 | 4:58 PM CST | EF0 | Ida, IA | 2.9 | 50 | $75,000 | ||
| December 15 | 4:59 PM CST | EF1 | Cherokee, IA | 11.2 | 250 | $1.0 million | ||
| December 15 | 5:00 PM CST | Unrated | Cherokee, IA | 1.8 | 50 | |||
| December 15 | 5:00 PM CST | EF1 | Cass, IA | 11.4 | 80 | $100,000 | ||
| December 15 | 5:01 PM CST | EF1 | Buena Vista, IA | 6.4 | 75 | $200,000 | ||
| December 15 | 5:05 PM CST | EF1 | Cherokee, IA | 3.8 | 75 | $250,000 | ||
| December 15 | 5:07 PM CST | EF1 | Buena Vista, IA | 6.9 | 150 | $100,000 | ||
| December 15 | 5:08 PM CST | EF1 | O'Brien, IA | 3.9 | 100 | $50,000 | ||
| December 15 | 5:10 PM CST | EF1 | Guthrie, IA | 11.4 | 70 | $100,000 | ||
| December 15 | 5:13 PM CST | EF2 | Sac, IA | 17.6 | 100 | $150,000 | ||
| December 15 | 5:14 PM CST | EF2 | Guthrie, IA | 19.7 | 100 | $450,000 | ||
| December 15 | 5:18 PM CST | EF2 | Buena Vista, IA | 4.8 | 100 | $250,000 | ||
| December 15 | 5:19 PM CST | EF1 | Carroll, IA | 9.7 | 80 | $80,000 | ||
| December 15 | 5:21 PM CST | EF2 | Guthrie, IA | 30.0 | 300 | $470,000 | ||
| December 15 | 5:27 PM CST | EF2 | Guthrie, IA | 23.4 | 150 | $801,000 | ||
| December 15 | 5:29 PM CST | EF2 | Greene, IA | 5.5 | 100 | $1.2 million | ||
| December 15 | 5:32 PM CST | EF2 | Greene, IA | 5.8 | 100 | $500,000 | ||
| December 15 | 5:34 PM CST | Unrated | Calhoun, IA | 1.3 | 40 | |||
| December 15 | 5:34 PM CST | EF2 | Greene, IA | 2.7 | 70 | $20,000 |
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.