A spell of CHILLY air is slated to affect the Carolinas this weekend and again next week.
The first of two waves of cold air will arrive this weekend via Canadian high pressure building in on the heels of a powerful low pressure system lifting toward the Canadian Maritimes. Low temperatures by Sunday morning in the mountains will likely drop into the 20s while the Upstate sees a decent potential for widespread frost and/or a light freeze.
In areas where the growing season hasn't ended yet, it probably will as a result of these conditions Sunday morning!
Another low pressure system is forecast to develop across the Carolinas and head for New England early next week. As this system strengthens and a temporary cross-polar flow develops, cold air will rush southward into the southeast states.
Cross-polar flow develops when a ridge of high pressure develops across the north Pacific into Alaska while a large trough of low pressure is carved across the east half of the contiguous United States. This air-flow emanates almost directly from the North Pole and is typically much colder as a result.
Expect another dose of overnight lows in the 20s for some mornings in WNC, and there is growing concern of a freeze occurring in a large part of the Upstate as well. The coldest morning could be Wednesday.
Last but not least, this cold air could be enough to create an opportunity for snow to fall across the southern Appalachians, including parts of western North Carolina, toward Tuesday. Some accumulation is possible and would be most likely near the TN/NC state border.