Re Jet Stream ...

Landmark study casts doubt on controversial theory linking melting Arctic to severe winter weather

By Paul VoosenMay. 12, 2021

Every time severe winter weather strikes the United States or Europe, reporters are fond of saying that global warming may be to blame. The paradox goes like this: As Arctic sea ice melts and the polar atmosphere warms, the swirling winds that confine cold Arctic air weaken, letting it spill farther south. But this idea, popularized a decade ago, has long faced scepticism from many atmospheric scientists, who found the proposed linkage unconvincing and saw little evidence of it in simulations of the climate.

Now, the most comprehensive modelling investigation into this link has delivered the heaviest blow yet:

https://www.sciencemag.org/news/2021/05/landmark-study-casts-doubt-controversial-theory-linking-melting-arctic-severe-winter