New York CNN Business  — 

Natural gas futures are climbing sharply ahead of a blizzard that will force millions of Americans to crank up the heat.

If maintained, the rally will translate to higher home heating costs in the weeks to come, adding to the inflationary pressures hitting the US economy.

Natural gas futures expiring in March surged 12% on Friday to $4.79 per million British thermal units. The contract hit an intraday high of $4.88, the highest level since late November. For the week, the March natural gas contract is up more than 25%.

Demand for natural gas, the most popular ways to heat homes in the United States, is likely to rise as Americans brace for a severe winter storm in the Northeast. More than 10 million people across 10 states are now in a blizzard warning.

“We are already maxed out” in terms of natural gas production, said Robert Yawger, director of energy futures at Mizuho Securities.

Beyond the storm, technical factors caused natural gas futures triggered a breathtaking spike on Thursday.

The more thinly traded February contract for natural gas spiked as much as 71% on Thursday to an intraday high of $7.35. It finished the day 46% higher to $6.27, marking what the Wall Street Journal described as a record one-day percentage gain.

Trading was so volatile that the exchange operator, CME Group, paused trading a dozen times.

“CME Group has several measures in place to ensure that our markets continue to work in an efficient and orderly manner at all times,” the exchange said in a statement. “This market worked as designed.”

Analysts blamed the price spike on the quirks of the futures market, specifically the fact that the February contract expired on Thursday. The looming expiration may have caused panic-buying from someone who had been betting against natural gas.

“Yesterday was ridiculous. That was expiration psychosis,” said Yawger. “We have not seen that kind of gyration in quite some time.”

Goldman Sachs similarly pointed to thin liquidity during short covering trades near the expiration of the February contract.

“We do not believe it was supported by fundamentals,” the Wall Street bank wrote in a Thursday note to clients.