A fast-moving winter storm could bring up to 4 inches of snow to York County on Saturday.

At least, that's what the weather forecasters predicted Friday morning.

A low-pressure system is expected to form Friday over the Mississippi Valley and move east toward the Outer Banks of North Carolina.

Its counter-clockwise motion will likely deliver snow to most of Pennsylvania later that night, according to the National Weather Service in State College.

A winter weather advisory is in effect in the York County area from 6 a.m.-7 p.m. Saturday, with 2 to 4 inches expected. Snow will be heavy for a brief time Saturday morning.

Tony Mach, a meteorological technician, predicted moderate accumulation of "dry" snow, which will start falling around midnight Saturday. Temperatures aren't expected to climb out of the lower 30s, he said, and will drop to the 20s overnight.

No snow is expected to fall Sunday, which will be partly cloudy in the morning and partly sunny in the afternoon.

It will the third snowstorm to hit York in a week. The area got a coating of snow Christmas Eve. Then a Wednesday storm dropped about 2 inches of snow on York, with 3.4 inches measured in Spring Grove. That storm hit during the day and prompted dozens of crashes across the county.

York County only got 12.4 inches of snow last winter, meaning this week's snowfall could equal close to half of what York got all of last winter.

- Erin James may also be reached at ejames@yorkdispatch.com.