It seems the Jet Stream was first discovered in the 1920s by a Japanese scientist. He sent weather balloons high into the atmosphere but found they were blown away by powerful high altitude winds sweeping eastwards. The rest of the world only learnt about the Jet Stream after the war when there were close ties with Japan. The jet stream is a river of wind 6 miles high and it course varies with the seasons. Cold Arctic air in the winter moves it further to the south while war tropical air pushes it back north in the spring. At the moment the jet stream is further to the south than expected, or has been most of the summer, leading to wetness in northern Europe. CAGW has locked into the jet stream, predicting it will stick in the north leading to drought in southern Europe.