After being chilled by the lowest temperatures in two years, several inches of snow could fall throughout the region late Sunday and Monday, lingering into Tuesday, forecasters say.

The National Weather Service’s first estimate sees something in the 4-to-6-inch range through the day Monday, with the potential for more Monday night and Tuesday, said Sarah Johnson, lead meteorologist with the National Weather Service Office in Mount Holly. She said the snow could continue through the day Tuesday.

She said the weather service would update forecast totals later in the day. An AccuWeather news release about the storm started with the words “Buckle Up.”

But on Friday afternoon, this still was very much a virtual threat, given that the storm still was thousands of miles away. And this obviously is not the winter to be taking marching, or shoveling, orders from the machines. “There’s still quite a bit of uncertainty,” she said.

» READ MORE: Snow is snubbing Philly in January, and February is looking mild across the nation

That said, something is coming, said Johnson. “It does look like we’re getting a classic coastal storm,” she said. The computer models, with evermore agreement, see the original storm spawning another storm on the Carolina coast it forming late in the weekend.

So much for the known. It is not at all clear how much of what falls would be snow, rain, or an icy assortment. As the storm cross the county and travels through the domain of the upper-air observation network, Johnson said, forecasters should get a better handle on the eventual outcome.

What is certain is the storm is being preceded by a deep chill, made all the more stinging by its remarkable absence the last two winters.

» READ MORE: When winter doesn’t come: Here are the winners and losers of Philly’s nearly snowless season

“It’s been a while since it’s been this cold,” said Johnson. Lows are due to fall to the mid-teens early Saturday, and the official temperature at Philadelphia International Airport hasn’t dropped below 20 since Jan. 20, 2020, and the mid-teens since Feb. 2, 2019.

An offshore storm is working in tandem with cold Canadian high pressure to draw in brisk northwesterly winds driving wind-chills not far from zero. Temperatures might not make it to 30 Friday afternoon, or to freezing Saturday.

It will be a few degrees warmer on Sunday as the storm approaches. For now the official forecast isn’t seeing any accumulation through Sunday night, suggesting the precipitation would get off to a slow start, and its Monday and Tuesday outlooks suggest a 100% chance of ambiguity.

» READ MORE: Philly may end January with just a trace of snow, as another threat passes. One last chance on Sunday?

Incidentally, if the snow arrives later than expected and none accumulate before midnight Sunday, this would become the first January in 25 years in which no measurable snow had fallen in Philadelphia.

Stay tuned.