A rain-loaded ‘atmospheric river’ stalled over the west coast of America threatens further ‘dangerous’ flooding, landslides and heavy snow. California faces a torrential deluge through the week as the state battles historic downpours which have left thousands without power and killed three people. A ‘siege’ of low-pressure storm systems –known as a ‘pineapple express’–will sweep the west coast prompting fresh warnings from national weather officials. California has this winter been the target for a series of atmospheric rivers – bands of moisture in the atmosphere carrying up to a tonne of rai…