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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