Arctic warming may lead to longer periods of extreme weather

A study shows that the decrease in temprature difference between the poles and the equator may lead to a more stable and more ondulating jetstream.
This can push cold weather deaper south and warm weather higher north.
This weather also remains there for a longer time.
This could explain the long warm winter in Europe this year,
the long cold winter in Europe last year
and the long cold winter in the US this year.