1600 ET - U.S. natural gas futures give back most of last week's gains as the heat than has kept up power-sector demand is set to dissipate. NatGasWeather.com notes "the same bearish factors that were in play last week," including strong U.S. production, weaker LNG exports and a bearish coming weather pattern. National demand will drop to "low to very low" for the 3-15 day period with the southern U.S. cooling several degrees while the rest of the country "will remain perfect temperaturewise," the forecaster adds. Nymex natural gas settles down 2.6% at $2.836/mmBtu.