By Paul Homewood
Climate scientists love to blame every bad weather event on global warming. Yet we never hear them cite climate change for the relative absence of bad weather!
One such example are tornadoes in the US, where we now have several decades of carefully collated data.
With the year near an end, we know that the number of tornadoes has been above average this year, though well below 2008 and 2011. Primarily this is due to several outbreaks in February and April:
Data since September is still provisional, so it is too soon to do a full analysis. But what we can safely say is that there have been no EF-5 tornadoes this year, the strongest category. This now extends the period without an EF-5 to six years, the last one being the Moore, Oklahoma tornado in May 2013.
There has only been one longer period without an EF-5, the seven years from 2000 to 2006:
It is also abundantly clear that powerful tornadoes were much more common in the 1970s.
The small numbers of EF-5 make estimation of trends difficult, but such trends are clearer with EF-4s. Provisionally there have been three this year, a figure now unlikely to change:
This is a continuation of low numbers in recent years, in stark contrast to the 1970s:
None of this is rocket science. Meteorologists fully understand that tornadoes, and the thunderstorms from which they form, depend on the clash of warm and cold air. Typically the warm moist air comes from the Gulf, whilst the cold air arrives from Canada. (More info here.)
According to global warming theory, the poles should warm faster than the tropics, which means that the type of thunderstorms we are talking about here would tend to be less powerful. In turn tornadoes should be less frequent and weaker.
I look forward to the BBC/Guardian reporting this good news.