Independent (UK): Millions of people living in southern England and the Home Counties were told to prepare themselves for up to 40cm (16in) of snow last night, as Britain remained in the grip of the longest prolonged spell of cold weather in 30 years. The Met Office issued its highest level of alert, warning of an impending “extreme weather event” that would bring travel chaos and threaten power supplies. Worst hit overnight will be Dorset, Wiltshire, Hampshire, Berkshire and Oxfordshire — parts of …