Hello Al Gore 2015: U.S. Sees Another Quiet Tornado Season – ‘Numbers Have Been Running Well Below Average, But, But Al Gore You Say That Global Warming May Spawn More Southeast US Tornadoes

"We see this trend in a lot of extreme weather," said lead study author Victor Gensini, a severe storms climatologist at the College of DuPage in Illinois. "Changes in the jet stream are causing the jet to break down and get stuck in these blocking patterns," Gensini said. "It just so happens it could be in a favorable pattern for tornadoes or a really bad pattern [for tornadoes]

We are now well past the peak of the tornado season in the US, so it is good to see that this year so far tornado numbers have been running well below average.

http://www.spc.noaa.gov/wcm/#data

This is now the fourth year in a row which has been below average.

http://www.spc.noaa.gov/wcm/torngraph-big.png

Looking at the longer term data back to 1954, adjusted for the fact that many more tornadoes are reported these days because of technology etc, this year is again shown to be amongst the quieter years.

http://www.spc.noaa.gov/wcm/adj.html

There have been no EF-5’s reported so far this year, the number of stronger EF-3’s and 4’s are also below the long term average, with 27 provisionally reported so far, compared with the climatological average of 37 at this time of year.

   

At this time of year, many tornadoes result from tropical storm systems, so with the quiet hurricane season continuing, we can hope that tornado numbers remain low.

https://notalotofpeopleknowthat.wordpress.com/2015/09/09/another-quiet-tornado-year-so-far/