1517 ET - U.S. natural gas futures lose ground as temperature forecasts are revised lower while production and inventories remain high. "Selling has been aided by cooler overnight trends and plunging global oil and gas prices due to optimism there will be positive developments in the U.S.-Iran conflict," NatGasWeather.com says in a note. Although the summer has been hot so far over most of the U.S., under-performing power-sector consumption and soft LNG exports have kept the inventory surplus from shrinking, the forecaster adds. Nymex natural gas settles down 3.6% at $2.682/mmBtu.