The recent winter storm left many people in the Piedmont and High Country scrambling to prepare as forecasts evolved day by day. For many reasons, this weather pattern was difficult to pin down.
Initial forecasts of heavy snowfall were driven by weather features over the Arctic and the Pacific Ocean south of Alaska. Those two systems had to meander around North America before phasing together and reaching the Triad.
National Weather Service Meteorologist Jonathan Blaes says their exact track determined who got rain, who got snow, and how much. To put it in perspective, he says, picture a storm system that’s 4,000 miles and seven days away, traveling at 100 miles per hour.
"If that speed is just changed by a few miles per hour, then it's going to end up in a different spot, very different, because it's seven days of speed changes," says Blaes. "So that little bit of incremental adjustment in its motion adds up over those seven days, and that means it could be located over New Jersey, over Charleston, and that kind of thing. So small, subtle details that seem trivial many days out have huge impacts."
Blaes and his colleagues study energy from jet streams and other sources and how they interact across multiple layers of the atmosphere, each layer with its own temperature.
For large storm systems like this one, the results can vary widely even within a 200-mile area: rain in Myrtle Beach, freezing rain in Lumberton and sleet with just a touch of freezing rain in the Triad.
Blaes says it’s often too early to tell what will fall where until a few days before the storm arrives.
"There's so many different details that go in there, and these winter storms are very humbling for forecasters," he says. "They're fun because they're hard and they're meaningful, they're impactful, but they also are very stressful and difficult."
Blaes says he’s monitoring another potential storm system that could affect the East Coast this weekend. He says it should be more straightforward: either dry and cold, some snow, or if you're right along the coast, a little rain.
