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Albert Square
26th Jul 2007, 23:57
We are told that the jetsream moving south has been a big contributor to the recent flooding in the UK. Has this had any effect on transatlantic air movements?

perkin
27th Jul 2007, 10:37
Actually, its not moving south, it just hasnt migrated north to allow the continental highs to push in over the UK in the Summer months...! ;)

Its also to do with the shape of the Rossby waves (kind of an 'S' shape in the jetstream, with the long axis of the 'S' approximately parallel with the equator). If my memory serves me correctly (its a while since I did any climatology/meteorology in my degree, so more knowledgable contributors please elaborate or correct me), its this that causes the jetstream to migrate - the Rossby waves become more acutely S-shaped in the Summer, carrying the jetstream further north above the UK. All related to global atmospheric circulation & just a bit of a blip this year...

BOAC
27th Jul 2007, 12:04
Albert - in the absence of any other factors, yes, routings westbound would PREFER to be to the north clear of the westerly jet and it would be nice to come home southerly in the jet.

Albert Square
28th Jul 2007, 23:07
Thank you perkin and BOAC for the replies. My first posting and a very useful response. I have now been reading more about the jetstream (or should I say the different jetstreams) and Rossby waves. It's a bit more complex than I thought!