“We can measure that distance of each individual photon traveling inside the snow,” says Hu, a researcher at NASA’s Langley Research Center.Just as an ant wanders around its underground colony, a photon shot from a space laser takes a random route through the snow.

"The plume pattern in the imagery instantly tells you without the need for radar or lightning observations or other information that these are the storms you really, really need to look out for," said Kris Bedka, an atmospheric scientist at NASA's Langley Research Center in Hampton, Virginia.