Weekend snow on Long Island? How forecasters track a potential storm with competing models.

The predictive models all tell different stories: There could be snow this weekend on Long Island. A lot of it.

Or, there could be none at all.

Forecasters at the National Weather Service in Upton are still trying to analyze the tracks of two systems moving into the area potentially Saturday night into Sunday to determine the most likely scenarios — this, based on AI-generated potentials and more traditional methods, such as projections based on climatology and probability.

"I would say that right now we’re monitoring the growing potential for a significant, accumulating snowfall event," weather service meteorologist Bryan Ramsey said Tuesday. "I would also say, we’re still too far out to tell."

The determining factor? The exact track of two cold air systems moving toward the Atlantic coast from the interior United States.

The first of those systems is bringing with it what the weather service said Tuesday should be "some of the coldest air of the season" — and the potential for wind chill values 15 to 20 degrees below normal with wind chills into the single digits for the weekend.

The second system? If it takes a more northerly track it will bring precipitation — a lot of it — and, because of the cold air in place, that precipitation will be snowfall, the weather service said.

"Let's say some of the models, even most optimistic, opt for a higher end total exceeding 6 inches [of snow], with some areas approaching a foot," Ramsey said.

"But that's if it were to make that northerly track."

If the second system pushes farther south?

The weather service said we could see no snow at all.

As of late Tuesday morning, the weather service said the chance of snow Saturday and Sunday is 40% to 60%.

Of course, that hasn’t kept many social media outlets from reporting a near-doomsday event on the level of blizzard.

Weather service forecasters will analyze the AI-generated models — the so-called GFS and European models; to the weather service, the American and European models — in addition to the traditional formats. But Ramsey said many social media forecasts will focus on just one of the probabilities, usually the one calling for the worst-case scenario.

"We see this a lot on social media," Ramsey said. "They’ll pick just one model, the one with the worst outcome, and they’ll post it as if it’s real and has been determined. It’s not a good way to forecast.

"A good forecast takes a lot of different factors into account, then we’ll forecast the most likely scenario — one based on history, probability, climatology; what we’ve seen before in similar circumstances," he said. "When all the models come together and show the exact same scenario, that inspires confidence. When they don’t and someone picks just one that claims a scenario, well ... let’s just say our confidence isn’t high in those cases."

While data being analyzed at six-hour intervals Tuesday by weather service forecasters suggests it’s still far too early to tell whether we’ll get snow or not — and how much we could see if we do get it — one scenario appears certain.

"It'll be cold," Ramsey said. "That's the one thing we can guarantee."

The weather service is calling for highs in the low 20-degree range Tuesday with temperatures falling into the teens overnight into Wednesday. The temperatures combined with strong, gusting winds of up to 28 mph could drop wind chill values as low as 5 degrees.

And while Long Island should see warmer, milder weather on Wednesday, Thursday and Friday, forecasters are calling for a steep drop into deep-freeze territory Friday night into Saturday, with overnight temperatures then around 10 degrees — and potential wind chill values below zero both days.

By John Valenti

john.valenti@newsday.com

John Valenti, a Newsday reporter since 1981, has been honored nationally by the Associated Press, Society of the Silurians and National Headliner Awards for investigative, enterprise and breaking news reporting, as well as column writing. He is the author of “Swee'pea,” about New York playground basketball star Lloyd Daniels. His debut crime novel, “For Nothing Is Hidden,” rooted in 1950s Long Island, was released in October 2025.