Ice storms can wreak havoc across cities, causing loss of power and creating slippery situations across town.
Here are seven things to know about ice storms:
- Ice storms happen during freezing rain events – No, ice doesn't magically fall from the sky like "Frozen" for it to be considered an ice storm. Ice storms actually happen during freezing rain events. Supercooled rain will fall, and when the surface is at or below freezing, that rain will freeze on impact.
- Heavy accumulations of ice can bring down trees and topple utility poles – Once rain freezes on contact, it accumulates onto an object. The weight of the ice continues to increase on the object, like trees or utility poles, and then will cause those objects to snap or fall.
- There doesn't need to be a lot of ice for it to be dangerous – Small accumulations of ice can be extremely dangerous to motorists and pedestrians. During ice storms, ice accumulations are considered significant at only a quarter of an inch.
- Ice Storm Warnings have specific criteria – An ice storm warning is issued when an ice storm event is expected to meet or exceed local ice storm warning criteria in the next 12 to 36 hours. Criteria for ice is 1/2 inch or more over at least 50 percent of the zone or encompassing most of the population.
- Bridges and overpasses are particularly dangerous during ice storms – Elevated surfaces freeze before other surfaces. Other elevated surfaces will likely freeze before other surfaces are on the ground.
- Snow can hide ice – If you have snow falling after a freezing rain event, this can be very dangerous. What may seem just a light dusting of snow could potentially hide a thick layer of ice.
- Black ice is just as hazardous – Black ice can also be a culprit that causes severe accidents. If you have an ice storm during the day, and the ice melts, but temperatures are to reach below freezing at night, this can cause black ice. When there is residual moisture on surfaces, like roads, it can freeze when temperatures dip below freezing overnight. This creates black ice and is not able to be seen easily.