During my first Maryland winter in college, I was baffled when a dusting of snow canceled classes for two days. I’d grown up in northern New Jersey, where a few inches of snow is just a Tuesday.

Now I cover Howard County schools, where predicting snow days has become something of a sport.

Freezing rain in the forecast? Expect a two-hour delay. Snow on the ground? That could be three days off. Is it just really cold? School might close for that, too.

That’s the ethos of the Howard County MD School Predictions Facebook page. Since 2019, whoever runs it has offered a not-so-scientific probability of a snow day when a storm is headed our way. Last month, the page predicted an 80% chance of a delay (that’s what happened), 30% chance schools open on time and a 10% chance for a snow day on Dec. 15.

Yes, that adds up to 120%.

An interview request sent to the Facebook page went unanswered.

Ahead of the predicted 5-18 inches of snow this weekend, the page teased its “boldest prediction” yet: 100% chance school is closed on Tuesday. (The kids already have off on Monday for a teacher professional day.)

Howard schools chief Bill Barnes acknowledged last month that it can seem like there’s no rhyme or reason to snow days.

“I understand those of you who are perplexed by the decisions made,” Barnes wrote in an email to students and families on Dec. 5, after schools opened on a two-hour delay following about an inch of snow.

Barnes said he gathers input from his team and external weather experts to make informed decisions with safety and predictability in mind., “A consistently conservative approach will be embraced,” he wrote.

School administrators can almost never win when deciding whether to close schools because of winter weather, said Jeffrey Halverson, a severe storms expert and contributor to The Washington Post’s Capital Weather Gang blog.

“It’s a damned-if-you-do, damned-if-you-don’t scenario,” the University of Maryland, Baltimore County professor said.

Capital Weather Gang runs Schoolcast, a far more scientific forecast system that predicts the likelihood of school delays or closures during winter storms in the Washington, D.C., area.

“We’re not always perfect — that’s why we give probabilities,” said Jason Samenow, the Capital Weather Gang’s chief meteorologist. “We try to give people a sense of how confident we are.”

They consider two key factors, Samenow said. First is the forecast for how bad the snow and ice will be. Second is how often school districts close and what the bar is for those closures.

“For larger school districts like Howard, Montgomery and Fairfax, they serve a large [geographical] area; they tend to err on the side of caution and take into account that weather conditions may be more severe in the northern and western portions than in the southern and eastern portions,” Samenow said.

One part of a county could be receiving more rain and ice while another section is experiencing more snowfall than ice, Halverson said as an example.

Leading to the question: “What’s the best size-that-fits-all [decision] for the entire county?”

Though a snowstorm last January brought around 6 inches of snow to Howard County, Halverson said it’s been about a decade since the last blockbuster storm. He’s hoping this one could end the snow drought.

“This will likely be our biggest [storm] event in many years,” he said.