A Scots Guard stands to attention outside Buckingham Palace during a snow flurry in central London April 4, 2013. Because of the cold weather, which has gripped Britain since the beginning of March, Britain's gas storage sites have been depleted by 93.71 percent, to just 299 mcm, according to data from Gas Infrastructure Europe. REUTERS/Chris Helgren (BRITAIN - Tags: ENVIRONMENT TRAVEL ROYALS ENERGY ENTERTAINMENT MILITARY)