To my untrained and inexpert eye, that naughty old jet stream seems to be
waaaaaay too far south. Is it having a winter holiday in the Mediterranean
or something?

http://virga.sfsu.edu/scripts/jetstr...lsml_fcst.html

"Togless" wrote in message
...
To my untrained and inexpert eye, that naughty old jet stream seems to be
waaaaaay too far south. Is it having a winter holiday in the
Mediterranean or something?

http://virga.sfsu.edu/scripts/jetstr...lsml_fcst.html

I don't think it is just having a holiday. It has emigrated.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

On Friday, March 22, 2013 4:46:54 PM UTC, wrote:
"Togless" wrote in message ... To my untrained and inexpert eye, that naughty old jet stream seems to be waaaaaay too far south. Is it having a winter holiday in the Mediterranean or something? http://virga.sfsu.edu/scripts/jetstr...lsml_fcst.html I don't think it is just having a holiday. It has emigrated. Will -- http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm Will Hand (Haytor, Devon, 1017 feet asl) ---------------------------------------------

The jet stream is elongating and therefore becoming far more wriggly. Its a bit like when you used to play snake with a skipping rope as a kid - the longer the rope gets the more wriggles it can develop. This is partly why standard weather forecasting is becoming much more difficult and uncertain. More difficult unless of course you know by how much the rope has lengthened!

On Friday, March 22, 2013 7:19:59 PM UTC, Mystic Piers wrote:

The jet stream is elongating and therefore becoming far more wriggly.

Is this a technical meteorological term?

On Friday, March 22, 2013 8:08:39 PM UTC, willie eckerslike wrote:
On Friday, March 22, 2013 7:19:59 PM UTC, Mystic Piers wrote: The jet stream is elongating and therefore becoming far more wriggly. Is this a technical meteorological term?

yes, a bit like the 'blizzardy outbreaks' term weve claimed as our own this remarkable season

Togless wrote in message
...
To my untrained and inexpert eye, that naughty old jet stream seems to be
waaaaaay too far south. Is it having a winter holiday in the
Mediterranean
or something?

http://virga.sfsu.edu/scripts/jetstr...lsml_fcst.html



Plenty of science in this paper
http://www.pnas.org/cgi/doi/10.1073/pnas.1222000110
and pdf
http://www.pnas.org/content/early/20....full.pdf+html

Quasiresonant amplification of planetary waves and recent Northern
Hemisphere weather extremes


Abstract

In recent years, the Northern Hemisphere has suffered several devastating
regional summer weather extremes, such as the European heat wave in 2003,
the Russian heat wave and the Indus river flood in Pakistan in 2010, and the
heat wave in the United States in 2011. Here, we propose a common mechanism
for the generation of persistent longitudinal planetary-scale high-amplitude
patterns of the atmospheric circulation in the Northern Hemisphere
midlatitudes. Those patterns-with zonal wave numbers m = 6, 7, or 8-are
characteristic of the above extremes. We show that these patterns might
result from trapping within midlatitude waveguides of free synoptic waves
with zonal wave numbers k ~ m. Usually, the quasistationary dynamical
response with the above wave numbers m to climatological mean thermal and
orographic forcing is weak. Such midlatitude waveguides, however, may favor
a strong magnification of that response through quasiresonance.

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