What We Know About the Winter Storm About to Hit the US—and What We Don’t

Over the past weekend, when weather models first started forecasting a winter storm that would sweep over large parts of the country, Sean Sublette, a meteorologist living in Virginia, started telling people in his area to prepare for snow. At the time, Sublette says, “a lot of the data started to point to a substantial snow storm for the mid-Atlantic and the Northeast, with significant ice farther southward into Carolina's Tennessee Valley.”

Then, Sublette woke up Wednesday morning. “I go through the data again, and I go, ‘Oh, fuck,’” he says. The models were now structuring the storm much differently.

“Some of the data is putting down crippling amounts of ice for my area of central Virginia,” he says. “This does not mean I am buying it hook, line, and sinker yet. But it is a sobering chunk of data to suggest heavy freezing rain, which is that type ...