A RARE weather phenomenon lit up the sky across the East Coast as a blizzard pummeled the region with up to two feet of snow.

Thundersnow was spotted above the One World Trade Center in New York City.

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Thundersnow lit up the sky above the World Trade Center in New York CityCredit: AccuWeather
 

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The phenomenon is incredibly rare and can only happen under specific conditionsCredit: AccuWeather
One onlooker was able to capture a look at the lightning above the World Trade Center in New York City as snow swirled on Sunday night.

Further north, meteorologist Jim Cantore witnessed lightning during the blizzard in Plymouth, Massachusetts.

“Holy smokes! We got it again,” he said as the lightning flashed across the sky.

Cantore saw the thundersnow in the exact same location he witnessed it during a winter storm in 2015.

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Thundersnow occurs when relatively warm, moist air near the ground rises rapidly to the colder air above it, creating the same atmospheric conditions that occur during thunderstorms in the summer.

But instead of rain, the falling precipitation is snow, and the thundercrack can only be heard within a two to three-mile radius because of the snow’s muffling effect.

The phenomenon is so rare because of the specific conditions that need to be met – the air on the ground needs to be warm, but still cold enough to produce snow.

Thundersnow usually occurs during a bomb cyclone and produces intense bursts of snowfall.

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A bomb cyclone occurs when a storm drops at least 24 millibars in pressure in 24 hours, which happened during this blizzard.

Up to two feet of snow blanketed parts of the East Coast as over 40 million people were under a blizzard warning from Maryland to Maine.

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Over 40 million people are under blizzard watch on Sunday and MondayCredit: Anadolu via Getty Images