Forecasters say the blizzard roaring into the Northeast overnight could be powerful enough to produce a weather phenomenon as loud as it is rare — thundersnow.
It’s just what it sounds like — snow accompanied by thunder and lightning. It happens when the atmosphere is especially unstable, and the National Weather Service in Boston is warning that it could occur during the worst of the approaching storm.
Severe weather expert Greg Forbes at The Weather Channel has a more detailed explanation. But suffice it to say that thundersnow is remarkable enough to surprise even the usually unflappable Jim Cantore: