Natural-gas prices rose Friday on forecasts for slightly hotter temperatures across much of the U.S. over the next two weeks, but analysts questioned whether the gains could be sustained in an oversupplied market. Natural-gas futures for August delivery settled up 4.4 cents, or 1.6%, to $2.770 a million British thermal units on the New York Mercantile Exchange. Hot weather boosts demand for gas-powered electricity, as households and offices turn on air-conditioning units. Though no extreme heat is expected this month, “today’s forecast is a bit warmer than yesterday’s” in the next 11 to 15 days, said private forecaster WSI Corp. in a note. Robust production has kept prices subdued this summer. The U.S. Energy Information Administration reported on Thursday that natural-gas inventories grew by 91 billion cubic feet last week, more than analysts and traders had expected. Gas stockpiles now sit at 2.7 trillion cubic feet, […]