Tornadoes: Really Getting Stronger?

You hear it all the time on weather reports. Tornadoes are getting higher in number and stronger in strength. Is it really true, or are we just getting better at reporting them? I did my own research. [First, the disclaimer: I used United States’ statistics from the NOAA, not worldwide data – reason being, decades-old data from less technologically advanced countries would likely be less reliable.]

First, the numbers (average yearly tornadoes by decade): 1950’s – 479; 1960’s – 681; 1970’s – 857; 1980’s – 819; 1990’s – 1,212; 2000’s – 1,272; 2010’s – 1,201; 2020’s (thus far) – 1,359.

As you can see, the average number of tornadoes in the U.S. increased each decade except for the ‘80s and ‘10s. The increases came at a much higher percentage than the decreases, which on the surface, would back up a warming planet causing more tornadoes. Not so fast. The 1960’s and early 1970’s saw a cooling trend, yet tornado numbers were on the rise. The 1980’s saw a warming trend, yet the numbers were down slightly. The same thing happened in the 2010’s. Are these two decades anomalies… or are they a result of better technology and reporting?

Tornadoes seem to be getting stronger because far more damage is being done and everyone now has a camera in their pocket or purse to record it. Again, not so fast. The population has more than doubled since 1955, as have businesses, and the number of households have tripled in the same time frame. Naturally there is going to be far more damage because there is far more property to damage. Add seventy years of inflation on top of that, cost of damages will obviously skyrocket.

Let’s look at the strength of tornadoes in the U.S. The last time the number of F5 (the strongest) tornadoes exceeded five (5) was in 2012. The highest number occurred in 1974 – more than 50 years ago. The last time the number of F4 tornadoes exceeded ten (10)… was also in 2012. The highest number occurred in 1965 – more than 70 years ago. Last time F3 tornadoes exceeded fifty (50) – 2011, and the highest number – also 1974.

This would imply tornadoes aren’t getting stronger. Again, to be fair… is it because we’re getting better at defining them? The answer appears to be yes. There is far more computing power. The Enhanced Fujita Scale was implemented in 2007 - it uses 28 indicators to determine strength. Since then, the percentage of F0 and F2-F5 tornadoes have actually decreased. Only the percentage of F1 tornadoes has increased, but they’re still almost always outnumbered by the F0 tornado (the weakest, and the most in number).

In summary, tornado numbers appear to be increasing, but high-end computers certainly track events that previously went unreported. Population increases and inflation undoubtedly have led to far more financial damages than in the past. The argument for generally stronger tornadoes seems to be false… though one must consider Enhanced Fijita Scale vs old-school methods of evaluating. My point is… question what you hear. Follow the money. Most scientists need an agenda to get grants… and get paid.

Source used: NOAA