When Winter Storm Grayson plowed into the East Coast earlier this month, it brought a few unwelcome gifts—namely brutal cold, power outages, coastal flooding, and whiteout conditions from Virginia to Maine. But the blizzard also gave parts of New York and New England the chance to experience the rare and thrilling weather event known as thundersnow. It happens when a snowstorm produces thunder and lightning, and has been known to send meteorologists into ecstasies of delight.
It might seem odd to have lightning flashing in the middle of a blizzard. In fact, thundersnow isn’t really that mysterious. “Lightning and thunder, they don’t care about the calendar, whether it’s January or any other month,” says Antti Mäkelä, a climate scientist at the Finnish Meteorological Institute in Helsinki. “If conditions in the atmosphere are favorable then lightning can occur and it’s the same type of lightning that occurs in the summertime.”
Thundersnow does have its dark side, though. Winter thunderstorms can be particularly dangerous exactly because they are so unexpected. Fortunately, we’re getting better at forecasting and understanding thundersnow.
He plans to keep investigating how often thundersnow really happens and where it occurs most frequently around the country. Studying these storms could reveal how much buildup of electric charge is needed for a cloud to produce lightning on its own. “We could definitely learn something about the fundamental processes associated with lightning,” Kumjian says.
He himself has only experienced the joy of thundersnow on one occasion. It happened during his time as a graduate student in Oklahoma when he stepped outside during a blizzard. “Within a couple of seconds of me standing outside, I heard a fairly loud boom and quickly jumped back inside because it took me quite by surprise,” he says.
Still, he said, it’s always exciting to hear—if not see—this rare phenomenon in action. “It’s basically just like a thunderstorm in the warm season, just it happens to be snowing outside,” Kumjian says. “But it still doesn’t take away from the magic of it.”
source: popsci.com By Kate Baggaley