After temperatures that reached the teens last week, the Lebanon Valley will receive only a brief respite from frigid conditions.
Following periods of snow on Tuesday, the Polar Vortex will move into the area bringing with it very cold temperatures.
The Polar Vortex will be sitting above the the region for nearly a week. Temperatures will remain under 30 degrees until Sunday. Thursday of this week is expected to be especially cold with a forecasted high of 12 degrees.
The Polar Vortex is a pocket of cold air, the coldest in the northern hemisphere, that typically sits above the North Pole. The air mass can move south, and when it does it routinely brings with it sub-zero temperatures and can sit in place for days.