After a week of above-normal temperatures, a snowstorm swept into southern Maine on Saturday afternoon and forecasts called for a return to frigid temperatures this week.

“It’s the dreaded polar vortex, back like a bad penny,” said Eric Sinsabaugh, a meteorologist with the National Weather Service. “Of course, it is January.”

Much of the snowpack in the southern part of the state had melted since last weekend, with temperatures that reached 50 degrees in some areas. But Saturday’s storm covered all the bare spots, and then some.

Heaviest hit was York County, which Sinsabaugh said would get about 7 inches of snow by the time the storm pulled out to the northeast Saturday night.

Snowfall in Greater Portland ranged from 4 to 7 inches, with the highest amounts mainly along the coast. The mountains and northern Maine escaped the snow altogether.

The snow caused road conditions to deteriorate Saturday, with the speed limit on the Maine Turnpike and Interstate 295 reduced to 45 mph. The lower speed limit was still in effect on both roads Saturday night.

By Saturday evening, the Maine State Police in Gray had received reports of about 10 accidents, but no one was injured. Dispatchers in York and Cumberland counties said they got reports of dozens of minor accidents, mostly cars sliding off roads or fender-benders, but no injuries.

Temperatures over the next two days should be in the low 30s, which is normal for this time of year, but that won’t last.

Sinsabaugh said temperatures will edge above freezing Sunday – “enough to melt the snow off the roads and sidewalks” – and be right around freezing Monday, but then they will plummet.

Sinsabaugh said high temperatures should be in the low teens Tuesday, around 10 degrees on Wednesday and might not make it out of the single digits Thursday. Overnight lows will range a few degrees on each side of zero.

The temperatures will moderate toward the end of the week, he said, with highs in the mid-teens Friday.

Edward D. Murphy can be contacted at 791-6465 or at: emurphy@pressherald.com