All of Pennsylvania is expected to see snow, mixed precipitation, and dangerously cold temperatures into next week.

The first chance of snow, according to AccuWeather, will come as the weekend comes to an end.

AccuWeather anticipates “bouts of nuisance snow and lake-effect squalls” across most of western and central Pennsylvania on Sunday.

A winter storm, and a rapid freeze-up, is expected into next week.

“AccuWeather meteorologists are still refining the exact details of how the storm will transpire in the Northeast, but residents should still prepare for potential disruptions to travel, classes and other daily routines and activities,” according to the report.

An Arctic cold front is expected to sweep across the eastern U.S. as a polar vortex plunges to the south.

AccuWeather reports that if the storm fails to develop, the bulk of the snow will likely fall in upstate New York, with the highest amounts expected in the Appalachians.

If the storm should form, it could mean “several inches of snow and a developing snowstorm from Pennsylvania on north,” according to the report.

“The storm can also bring another round of gusty winds to the Northeast, adding to the potential impacts the storm will have on travelers,” AccuWeather reports.

Thanks to the polar vortex, temperatures are also expected to plummet well below-average.

AccuWeather forecasters predict that a polar vortex could bring single-digit temperatures, with below-zero windchills, to central Pennsylvania next week.

A polar vortex is a large pocket of very cold air, typically the coldest air in the Northern Hemisphere, which sits over the polar region during the winter season, according to AccuWeather. Dave Samuhel, an AccuWeather meteorologist, said that vortex is expected to move southward as it is pushed by warmer air near the North Pole.

Here’s a look at the forecast for Harrisburg:

Saturday - Mostly cloudy skies. High: 35

Saturday night - Cloudy skies. Low: 23

Sunday - Considerable cloudiness. High: 44

Sunday night - Mostly cloudy skies. Low: 19

Monday – Intervals of clouds and sunshine. High: 38

Monday night – Thickening clouds. Low: 27

Tuesday – Cloudy skies, a little snow and rain expected. Little or no accumulation. High: 38

Tuesday night - Intermittent snow, 1-3 inches possible. Low: 14