Tuesday, as a winter storm was bearing down on the Washington area, Kristen Allen was in the typical parental purgatory of waiting to hear how her kids’ schools would weather the weather: open, closed or two-hour delay.

But the Allens’ Arlington household is at the mercy of not one school system, but three. With children enrolled in public and private schools across three jurisdictions, a snow day becomes an algebraically complicated matrix of who needs to be where, when and for how long. Worse — or better, if you don’t mind seeing your siblings suffer a bit — it can be a game of Russian school-ette, a survival-of-the-luckiest rivalry with one or two kids slogging out into the wintry mix even as the lottery winners are cuing up Netflix for a “Modern Family” bender.

“I like to text my brother during the day, ‘Hey, how’s school?,’ ” said Catheryn Allen, 14, a freshman at Bishop O’Connell High School in Arlington, which links its weather rulings to the Fairfax County school system. She’s not shy about making clear she is communicating from the couch, game console in hand, as her brother Mason, 16, grinds through a normal day at Gonzaga College High School in the District, which follows the weather dictates of Montgomery County Public Schools. “It gets pretty heated at times.”

It’s a familiar cold-weather ritual for families who split kids among several jurisdictions. Beholden to more than one front office, these families have a special perspective on the relative winter wimpiness or flintiness of regional school systems.

Kate Eager and her husband live near Ashburn and have three kids in Loudoun County schools, a system prone to “calling it at two snowflakes,” she said.

But her oldest son, Liam, is a sophomore at Gonzaga, which Eager said closes less frequently but sometimes waits until the last minute. Sometimes the 15-year-old launches his hour-long Metro commute at 6 a.m., only to have the school weather lords rule in his favor before he even gets there.

“He’s definitely upset when his siblings are all outside playing in the snow,” Eager said.

The Allens have dealt with such a wintry balancing act for the past decade (three older siblings are off at college).

“It changes from year to year,” said Kristen Allen, who also has a 12-year-old, Peter, at Arlington’s Williamsburg Middle School. “This year, Fairfax and Arlington have been delaying or canceling a lot quicker than Montgomery. In the past, Montgomery was a lot quicker to fold.”

That shift may have to do with a Maryland state mandate to begin the school year after Labor Day, leaving Montgomery County with fewer snow days to burn and the Allens at the mercy of another state’s politics. So, too, can distant geography wreak havoc on her morning routine of getting three students to three homerooms miles apart. Allen knows that the snowfall in the far-flung corners of the counties that hold her fate can drive school closing decisions, even when it’s dry 25 miles away on her block.

“It’s the Darnestown effect,” she says of one of the most snow-prone corners of Montgomery. “Or the outer edge of Fairfax County, a completely different weather system.”

When the storm is a well-forecast slam dunk, such as the one slated to deliver a messy coating of snow, rain and ice starting early Wednesday, all the schools close, all make the call early, and everyone settles in for the duration.

The alert from Arlington schools — “All APS Schools and Offices Closed”— beat Montgomery’s by one minute Tuesday afternoon. Fairfax was a half-hour ahead of both, word coming via Cathryn’s field hockey group chat.

“So, just built a fire in the fireplace and the kids are all outside since homework can wait,” Allen said by email.

But on days when the call is closer, the waiting begins at least a day in advance of the first flake. Parents and kids alike will crowd around the kitchen TV, scouring the map, knowing that wind direction could decide the winners and losers among them. The finger of fate hovers over a single household, anointing some, flicking others.

“If it’s coming from the southwest, they know Fairfax is going to get hit,” Allen said of the mini meteorologists in her family. “If it’s a nor’easter, Montgomery is more likely.”

And then the trash-talking begins. Students dissing administrators in distant county seats who hold such indirect sway. “Fairfax is closing again? Do you ever go to school?”

Well, it’s hard when your siblings get the good word the night before and you have to wait until dawn. At least gone are the days when Allen would get up at 5 a.m. to listen for the school’s closing list on the radio, then turn off the alarms of the lucky ones, waking them just enough to allow for a little fist-pump of triumph under the blanket.

Now, everyone’s wired to the county’s alert networks and Allen is off the hook.

“The kids are so invested in the outcome that I don’t have to manage it very much,” Allen said. “They are usually the first ones to tell me.”

She is in charge of the transport matrix that has to be adapted to three different outcomes, a spreadsheet’s worth of carpools and Metro trains, beholden to a shifting overlay of delays, cancellations and early release calls. The middle-schooler walks.

“When it’s last-minute, it’s a bit of a scramble,” she said.

Still, the Mid-Atlantic winter is a sprint between December and March, Allen said, and even a reliance on counties where they don’t live for their school decisions is worth access to multiple good schools.

What’s harder, she said, is coordinating three different spring breaks. They never line up.

“We haven’t been on a spring trip in nine years,” she said.