What is an Ice Storm?

An ice storm occurs when frozen rain or hail blankets a region. Not only do roads freeze, but also ice coats trees, bushes and power lines. Because of the weight of the ice, this type of storm can cause tremendous damage to an area, pulling down trees and power lines. A few past ice storms have caused farmers to lose entire crops or power to be lost for many days.

Typically, an ice storm occurs when the ground temperature is below freezing 32 F (0 C). Above ground, the temperature is close to freezing. These storms are common in areas where one doesn’t see a lot of snow, because they don’t require the same degree of cold that would produce snow.

However, an ice storm can also affect areas that do get snow yearly. In 1998, such a storm hit Northern New York, and parts of Eastern Canada. It was immensely destructive, damaging numerous maple trees in Canada that are relied upon for the maple sugar industry. It also caused power loss for many people, about three million. Many did not have power restored for up to six weeks.

This ice storm and others are more challenging than snowstorms because they can destroy so much with a relatively small amount of ice. Generally to be defined as an ice storm, one quarter of an inch of ice (.635 cm) must fall. A quarter of an inch of snow, conversely, tends to be much easier to manage, even in regions where snow is uncommon.

Roads become perilous to drive upon because they are frozen. People lose power, crops, and trees can be pulled down. People can and have died because of limited access to driving, and thus to medical facilities, or because they may not have inadequate heating systems in their homes or emergency generators.

The 1998 storm in New York and Canada caused about 3 million US dollars (USD) worth of damage. Loss of work days and stalled business can be incalculable. Other storms have resulted in even greater financial damage. The president of the US declared parts of Kansas a disaster zone after it was hit by an ice storm in 2005. At least 39 million USD of estimated damage occurred.