'Polar Vortex' Looms Over Thanksgiving Travel In PA: Early Holiday Forecast

The chaos of the Thanksgiving travel week could be compounded by stormy weather in eastern Pennsylvania and the potential impacts of a looming "polar vortex", according to forecasters.

The atmospheric disruption high in the Arctic could cause changes in the stratosphere that will have a chilling ripple effect on many parts of the country, including a colder December than normal, CNN reports.

The impacts could be felt as soon as this week.

Meanwhile, a system moving northeast across the country could make for some rainy and slick roadways in the days before Thanksgiving, forecasters predict.

Rain could begin as early as Tuesday afternoon and continue through Wednesday evening. However, the total precipitation and intensity of the weather is still highly dependent on the track of the storm.

"The storm will be losing some of its intensity and moisture as it travels from the Central states to the Northeast, but given the travel volume, even a few hours of rain can create significant problems on the roads and runways from Washington, D.C., to Philadelphia, New York City and Boston," AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.

Rain is currently not in the forecast for Thanksgiving Day itself, with the system likely moving through before turkeys hit the oven.

The vortex could further complicate matters, making travel conditions even more dicey if roads freeze over. While the current long range forecast calls for lows in the 40s, that could very well change.

"Temperatures are currently favored to be below normal by the National Weather Service Climate Prediction Center for the Thanksgiving holiday weekend across a large portion of the lower 48. For our local area, this would translate to highs in the 40s and lows in the 20s."

The exact causes of the atmospheric disturbances that cause polar vortexes remain unclear and are under study by scientists. However, it is extremely unusual for a vortex to develop this early in the year.

AAA said they expect a busier Thanksgiving on the roads and in the air than a year ago. Some 81.8 million people are expected to travel at least 50 miles from Tuesday, Nov. 25 through Monday, Dec. 1. That's an increase of some 1.6 million over last year.

Roughly 73 million of those travelers will be on the roads.

Here's the long range forecast for the area through Thanksgiving Day, according to the National Weather Service:

Friday
Cloudy, with a high near 56. Southwest wind around 5 mph.

Friday Night
Rain, mainly after midnight. Low around 46. Calm wind becoming north around 5 mph. Chance of precipitation is 80 percent. New precipitation amounts between a tenth and quarter of an inch possible.

Saturday
Rain likely, mainly before 7 a.m. Cloudy, then gradually becoming mostly sunny, with a high near 53. North wind 5 to 10 mph. Chance of precipitation is 60 percent. New precipitation amounts of less than a tenth of an inch possible.

Saturday Night
Mostly clear, with a low around 32. North wind around 5 mph becoming calm in the evening.
Sunday

Sunny, with a high near 52. Light northwest wind becoming west 5 to 10 mph in the morning.

Sunday Night
Mostly clear, with a low around 36.

Monday
Sunny, with a high near 55.

Monday Night
Mostly cloudy, with a low around 40.

Tuesday
A chance of rain after 1 p.m. Cloudy, with a high near 58. Chance of precipitation is 30 percent.

Tuesday Night
Rain likely, mainly before 1 a.m. Mostly cloudy, with a low around 52. Chance of precipitation is 70 percent.

Wednesday
A chance of rain. Mostly cloudy, with a high near 63. Chance of precipitation is 40 percent.

Wednesday Night
A chance of rain. Mostly cloudy, with a low around 44. Chance of precipitation is 40 percent.

Thanksgiving Day
Mostly sunny, with a high near 52.