Natural gas prices sank to a three-week low on Friday, as cooler weather forecasts convinced traders that summer demand won’t be enough to absorb near-record production. The front-month September contract lost 5.2 cents, or 1.9%, in price to $2.716 a million British thermal units on the New York Mercantile Exchange. It is the market’s lowest settlement since July 8. A two-day slide turned what had been a decent month for natural gas into its worst since January. Futures ended the month down 4.1%, with all the losses coming Thursday and Friday. Weather forecasts for the coming weeks show heat dissipating and large parts of the country likely to get cooler-than-normal temperatures. In the spring, prices had rallied about 20% from a three-year low, but that was partially dependent on expectations that hot weather would cause power plants to burn off high supplies of natural gas to […]