Oil prices edged higher Tuesday as traders weighed forecasts calling for mild U.S. weather next week against anticipated further production cuts by OPEC.

Light sweet crude for January delivery rose 21 cents to $62.65 a barrel on the New York Mercantile Exchange. January Brent crude at London's ICE Futures exchange was up 40 cents at $63.85 a barrel.

Also on Tuesday, the U.S. Energy Department released its annual long-term world energy forecast. The agency predicted that the price of oil, when adjusted for inflation, would decline between 2007 and 2015 as investments made in recent years of historically high prices bring new supplies to the market.

After that, the Energy Department said it expects prices to resume an upward trend, bringing average real prices (in 2005 dollars) by 2030 to more than $59 a barrel. In nominal terms, that would be equivalent to about $95 a barrel. The agency said it expects OPEC to adjust its output over the next 25 years to try to keep average prices between $50 and $60 _ a range it is already trying to achieve.

In the very short-term, energy analyst Victor Shum said he expects the oil market to strengthen further as demand increases during the Northern Hemisphere winter. He predicted that $60 a barrel was the new price floor.

"In the short-term future, what's still going to move the market is the weather," said Shum, of Purvin & Gertz in Singapore.

At the moment, however, the U.S. autumn has been marked by relatively mild weather. Nymex natural gas fugures fell 7 cents to $7.73 per 1,000 cubic feet, while heating oil futures were steady at $1.809 a gallon. Unleaded gasoline futures were flat at $1.6674 per gallon.