U.S. Northeast power and natural gas prices for Dec. 16 jumped to their highest level in almost a year as energy companies prepare for what could be the region's biggest winter storm in years.

Meteorologists at AccuWeather said the Nor'easter could unload 2 ft (61 cm) of snow or more, while temperatures will reach only the upper 20s to low 30s F (-2 to zero C) in New York and Boston over the next few days.

Normal highs are in the low 40s F in those cities at this time of year.

Since most Northeastern homes and businesses use gas for heat and much of the region's electricity comes from gas-fired power plants, electric and gas prices usually soar during extremely cold weather.

Next-day power and gas in New England and gas prices in New York rose to their highest levels since December 2019.

New York and New England do not have enough gas pipeline capacity to supply all the fuel needed for both heat and power generation on the coldest days, so many gas-fired plants have to switch to more expensive oil when temperatures drop.

The group responsible for reliability of the North American power grid warned in November that extreme weather could put New England fuel supplies at risk.

So far on Dec. 16, however, power generators in the region were still getting all the gas they needed and ISO New England, the regional electric grid operator, said the system was operating normally.

"We don’t expect the storm to have a significant impact on the transmission system, but ... storms like this can be unpredictable," ISO spokesman Matthew Kakley said.

The ISO said New England's power plant fuel mix was 55% gas, 25% nuclear, 10% renewables (mostly wind and wood), 7% hydro, 2% coal and less than 1% oil the morning of Dec. 16.