Independent: It travels around the world at up to 200mph, at altitudes of between five and seven miles. It controls Britain's weather and can make or break a summer holiday. But something is happening to the jet stream that could explain why Britain has experienced a conveyor belt of storms dumping huge amounts of rain onto flood-battered parts of the country. Scientists are increasingly convinced that the jet stream is stuck in a position that has thrown warm, moisture-laden air from the Atlantic over Britain...