U.S. natural gas futures tumbled more than 6% to hit a two-week low on Friday, as updated weather forecasting models for the first two weeks of December pointed to a return to mild weather, prompting investors to bet that utilities and homes will burn less natural gas as demand for heating falls. On the New York Mercantile Exchange, natural gas for delivery in January plunged 27.1 cents, or 6.22%, on Friday to settle at $4.084 per million British thermal units by close of trade. Nymex gas prices touched a session low of $4.079 per million British thermal units earlier in the day, the weakest level since November 14. Futures were likely to find support at $3.931 per million British thermal units, the low from November 14, and resistance at $4.367, the high from November 28. Nymex natural gas prices lost 18.2 cents, or 4.26%, on the week, as forecasts for milder temperatures to settle in across much of the U.S. in early December weighed. Bearish speculators are betting on the mild weather to dampen demand for the heating fuel. The heating season from November through March is the peak demand period for U.S. gas consumption. Meanwhile, the U.S. Energy Information Administration said in its weekly report that natural gas storage in the U.S. fell by 162 billion cubic feet last week, compared to expectations for a decline of 150 billion. The five-year average change for the week is a drop of 6 billion cubic feet. Total U.S. natural gas storage stood at 3.432 trillion cubic feet as of last week, 9.2% below year-ago levels and nearly 10.4% below the five-year average for this time of year. Natural gas prices had been on a roller coaster through November as investors reacted to daily changes in weather patterns. Despite the disappointing weekly performance, natural gas futures rose 5.6% in November as expectations of cooler-than-normal temperatures at the start of the heating season had lifted prices earlier in the month. Elsewhere on the Nymex, crude oil for January delivery settled at $66.15 a barrel by close of trade on Friday, down $10.36, or 13.54%, on the week. Nymex oil futures plunged to levels not seen in more than four years on Friday, after the Organization of the Petroleum Exporting Countries decided not to cut output at the conclusion of its highly-anticipated meeting. Meanwhile, heating oil for January delivery slumped 10.14% on the week to settle at $2.161 per gallon by close of trade Friday.