Scientists have proposed mysterious weather patterns could be explained by blockages in global flow of air currents called jet streams. On exceeding jet stream capacity, 'blocking' occurs which could be modelled for weather forecasts, said researchers. The 2003 European heat wave, California's 2014 drought and Superstorm Sandy in 2012 were caused by the same weather phenomenon, noted researchers. Much like car traffic, movement slows when multiple highways converge and the speed of the jet stream is reduced due to topography such as mountains or coasts. 'It's very difficult to forecast anything until you understand why it's happening, so this mechanistic model should be extremely helpful,' Scientist Nakumara said.