Jane Spofford of Boothbay said the view from her picture window is never boring. “There’s always something happening,” she said. “I see seals, ospreys, eagles… You name it!”
But on Dec. 21, as she sat in a favorite chair enjoying the view during a major snow storm, even Spofford was surprised when the whole sky lit up in a sudden flash, followed by a loud rumble of thunder.
“I’ve never seen anything like that before,” Spofford said. “The snow was coming down fast and hard, and then I saw the whole horizon light up, not just a single lightning bolt. Then the thunder that followed was quite loud – my husband heard it in the kitchen.”
Spofford’s window faces in a south-easterly direction from her home on Barter’s Island, so she believes the event occurred over the area of the Damariscotta River mouth.
Spofford’s observation is consistent with a weather phenomenon known as ‘thunder snow,’ according to meteorologist Eric Sinsabaugh with the National Weather Service (NWS) in Gray.
Thunder snow is a thunderstorm with snow falling as the primary precipitation instead of rain, according to Sinsabaugh, and according to an article in the New York Times by Fred Gadomski, meteorologist at Pennsylvania State University.
It commonly falls in regions of strong upward motion within the cold sector of extra tropical cyclones between autumn and spring when surface temperatures are most likely to be near or below freezing.
A key part of Spofford’s observation is describing the entire horizon lighting up, as opposed to a bolt of lightning arcing from sky to ground.
The lightning generated by thunder snow often travels from cloud to cloud, thereby filling the skyline with a flash of light that is further enhanced by reflecting off snowfall in the air, according to Sinsabaugh. The thunder generated also has a different sound – deeper and louder than regular thunder because of the density of the snow-filled atmosphere.
While reports of thunder snow are infrequent, the conditions for it are often found during major winter storms along the Maine coast, according to Sinsabaugh.
There was a second report in Maine during the Dec. 21 storm in which a witness in Hollis heard thunder, but did not see lightning, according to Sinsabaugh.
