SAN FRANCISCO (MarketWatch) -- Natural-gas futures climbed higher on Thursday after the U.S. Energy Information Administration reported a smaller-than-expected supply increase of 57 billion cubic feet for the week ended Aug. 16. Analysts polled by Platts forecasted a climb of between 67 billion cubic feet and 71 billion cubic feet. Total stocks now stand at 3.063 trillion cubic feet, down 238 billion cubic feet from the year-ago level and 44 billion cubic feet above the five-year average, the government said. September natural gas     (ngu13)   was at $3.55 per million British thermal units, up 9 cents, or 2.5%. It was trading at $3.50 before the data