Areas of the Southeast United States are susceptible to ice storms, including Massachusetts. Ice storms are a type of winter storm that is caused by freezing rain. As snow falls, it encounters a warm layer of air in the middle of the atmosphere that turns it to rain. Before the rain hits the ground or the surface of an object, it encounters a very shallow layer of cold air that causes the rain to freeze on the cold exposed surfaces. The ice accumulates on trees, power lines, bridges, and roadways causing significant damage and dangerous driving conditions.
On December 11-12, 2008, a destructive ice storm affected interior southern New England, producing a significant amount of ice accumulation of 0.50 to 1.00 inch. Portions of north-central Massachusetts and southern New Hampshire experienced the brunt of the storm, as the ice storm knocked down numerous trees and power lines, leaving many residents without power for weeks.