All this talk about tornadoes reminded me of the Tornado application that I wrote a few years ago that parses the TORN data series of tornadoes thats available from the National Weather Service Storm Prediction Center. It’s still to be updated with the data for 2020 but its complete from 1950 to 2019 so I downloaded this latest data to look at some of the statistics that you can glean from it. Here is the average daily count of all tornadoes in the data series since 1950 overlaid with a 7 day centred average. As you can see tornadic frequency is at its highest during the spring months of April, May and early June, with the peak occurring around the 20th of May, although as you can see no month is immune from tornadoes in the United States.
The next bar chart is the total number of tornadoes reported each year since 1950. Obviously the reporting of tornado outbreaks has got better during the last seventy years so I haven’t added a linear trend to the series which would be skewed upward at an alarming angle and prove not much at all. The totals look a little more consistent since the late 1980’s but without ten or more years of data I wouldn’t like to say if the frequency is increasing or not. The 2020 season was below average as far as tornado activity was concerned in the United States.
2020 was the deadliest year of tornadoes in the United States since 2011. Despite this, it ended up being the least active year in terms of the number of confirmed tornadoes since 2016, mostly due to six of the final eight months being significantly below average.Wikipedia
Category five tornadoes are quite rare even for the United States the capital city of tornadoes in the world, and as far as I see one hasn’t occurred there since 2013. The destruction from a category EF 5 tornado is described like this in the Enhanced Fujita scale:
Well-built frame houses destroyed with foundations swept clean of debris; steel-reinforced concrete structures are critically damaged; tall buildings collapse or have severe structural deformations; cars, trucks, and trains can be thrown approximately 1 mile (1.6 km).
Below is a map of the EF 5 tornadoes and their tracks which have occurred since 1950 in the data series to illustrate what I mean.
I haven’t extended my application since I wrote it mainly because (a) the data is only really relevant if you live in the United States, and (b) the National Weather Service Storm Prediction centre has such a superb website that provides so many wonderful graphs and tables about all things regarding tornado activity which I just couldn’t ever hope to match.