Forecasts are seeing a possible six inches of snow for Philly Friday into Saturday. Oh, you’re skeptical?

» UPDATE: Read the latest on the snow forecast here

A significant snowfall is possible Friday night into Saturday in the Philly region, and the chances are excellent that if you’ve been around here you heard something similar last week, and the week before that, and the week before that.

In its first accumulation estimate, the National Weather Service in Mount Holly was calling for as much as 6 inches in the Philadelphia region, with perhaps a foot at the Shore, said meteorologist Patrick O’Hara.

Don’t start shoveling yet, however. Computer models on Wednesday were indicating the storm would mature farther out to sea than earlier predicted, O’Hara added. If that trend continued, that would reduce snow totals.

“it needs to be stressed this storm is still more than 48 hours out and has yet to even develop yet so expect changes to the snowfall forecast,” the weather service said in its afternoon discussion.

Sarah Johnson, a lead meteorologist at the Mount Holly office, is among those who have noticed that storms keep popping up on the computer models, then poofing out, leaving the immediate Philadelphia area with not much more than road-salt residue and that vague taste of the sea in the air.

In the latest iteration, during the last few days the models have creamed then erased — erased and then creamed — parts of the Northeast megapolis with anywhere from 2 inches to 2 feet of snow, with the higher fantasy amounts in New England.

» READ MORE: In Philly winters, expect anything

On Wednesday it appeared all but certain that something major would ignite off the coast.

“It’s going to be a strong storm,” said O’Hara.

It wasn’t at all certain, however, what it would mean for Philly. Snow was “likely” Friday night into Saturday morning, the weather service said. If all the planets aligned (or misaligned) the region could see 6 to 12 inches, with the high amounts more likely near the Shore.

Computer models never will be able to fully capture and predict the state of the atmosphere. But in years past meteorologists such as NBC10′s Glenn Schwartz have championed and counted on the European Center for Medium-Range Forecasts — or Euro — as the gold standard and a critical forecast tool.

Not this year.

» READ MORE: For computer models, change is a constant

“I, along with many others, have been shocked at its poor performance this winter,” said Schwartz. He said that in some instances the Euro has been playing catch-up with its American counterpart. In this case, the two models have flip-flopped, adding more uncertainty to the forecast.

Tony Gigi, a former weather service meteorologist who now helps the philly.wx weather-discussion board, suggested that the Euro seems to have performed well in predicting the behavior of the upper atmosphere, but PennDot doesn’t plow up there.

“Maybe it has reached a critical point where improvements in one area ... have caused degradations in other areas which have more of an impact,” he said.

On its site, the European Centre makes no claims to infallibility. It cautions that “any forecast we produce is limited by the fact that the atmosphere is chaotic.” It points out that its models can’t “perfectly represent the laws of physics,” nor can they fully account for things such as cloud formation. “This means that all forecasts will have some uncertainty,” it said.

And the same caveats would apply to all models, and the challenges for the coming threat are particularly formidable, meteorologists say.

“There’s a whole lot of moving pieces,” said Carl Erickson, a meteorologist with AccuWeather Inc., adding a light snowfall could precede the storm during the day Friday.

For the main event, computer models were foreseeing that erstwhile Pacific disturbance dropping into the Southwest and eventually redeveloping off the Atlantic Coast, a so-called Miller-B storm, named for the researcher who developed the classification.

Sometimes that “B” can stand for bust around here as they often blow up too far north and-or east to affect Philadelphia.

» READ MORE: Road brining before winter storms is gaining more traction around Philly and the nation

Whatever does or doesn’t happen, PennDot is grateful for the heads-up, said maintenance supervisor John Krafczyk, even if it means a wasted salt run, overtime, or lost costs in rental plow trucks.

The advance notice gives the agency time to review staffing, compounded by COVID-19 these days, and work up contingency plans.

PennDot could start brining roads as soon as late in the day Wednesday if the forecast holds.

It has been known not to.