Reuters: Weather and renewable energy supplies across much of western Europe could be hit this winter by the North Atlantic Oscillation (NAO), a phenomenon that can exert a powerful influence over temperature and rainfall. Meteorologists say a negative NAO usually points to colder, calmer and drier winters in northern Europe and wetter, windier weather across the Iberian Peninsula and Italy as westerly winds from the Atlantic are pushed south. The NAO has been negative since last autumn, pointing to…