Natural gas futures strengthened for the second day in a row, this time on what forecasters said was the potential for a “material change” in the weather pattern before the new year begins. The January Nymex gas futures contract settled Wednesday at $3.815/MMBtu, up 10.7 cents day/day. February climbed 10.0 cents to $3.774.

Spot gas prices also continued to rise across most of the country. However, massive losses on the East Coast sent NGI’s Spot Gas National Avg. down 36.0 cents to $4.200.

Though futures prices started the week off in positive territory, Monday’s gains were seen as more of a technical correction after the extensive sell-off in prior sessions. European gas prices also have surged this week on the arrival of the continent’s first widespread cold blast,...