Wavier jet stream 'may drive weather shift' ?

[Warren Faidley]

This is rather interesting.

Would like to hear opinions on how this might effect spring chasing.

http://www.bbc.co.uk/news/science-environment-26023166

Warren

 

[MClarkson]

Baroclinic instability is directly driven by the temperature gradient, which should be decreasing. You would think the magnitude of waves would decrease, not increase. I do not know what the impact on the planetary wavenumber (and thus in part propagation speed) would be.

However neither of these effects are distinguishable from noise at this point.

 

[Mark Ellinwood]

Articles exactly like this pop up just about every year. I'm not for or against the results of the research... just wanted to state that such conclusions have never been substantiated well and there is not enough evidence to make a clear distinction between whether it's related to climate change or is just natural variability.

 

[Paul Knightley]

A natural response to a decreasing temperature gradient will be a wavier jet - if there is less overall 'velocity' then it will be more prone to large meanders - consider a river: when it has a lot of velocity (mountain stream) it tends to go fairly straight; when it is moving more sluggishly (downstream) you get large meanders, and sometime ox-bow lakes (in the atmosphere, a cut-off low).

Of course, we've seen some large meanders this winter - but it doesn't mean all of the jet is sluggish. Here in the UK we've been sat at the end of a powerful Atlantic jet for most of the winter, and had storm after storm, and quite likely the wettest winter on record.

Ultimately, larger meanders will mean more extreme temperature contrasts between locations and seasons - but there is no guarantee of what side of any meander you might be on in any season! Thus, if a large trough sets up over the western USA in May, and sticks there, you know what that means! But the trough might set-up to the east and stick there.