1000 ET - U.S. natural gas futures add to yesterday's gains with support from late-summer heat that should keep up power-sector demand. "Weather models remain to the warm side for 2/3 of the U.S.," Dennis Kissler of BOK Financial says in a note. The expectation that tomorrow's EIA storage report will show a below-average weekly injection "is kicking in some short-covering buyers in the early trade this morning," he adds. Nymex natural gas is up 3.4% at $2.87/mmBtu.