The Science Behind Ice Storms

Winter storms commonly cause many extenuating factors, but one type of storm that can be particularly damaging is the ice storm.

Ice storms, which precipitate freezing rain, cause the glazing of surfaces with ice. As more and more ice accumulates, the severity of the impacts increase. Heavy layers of ice can topple power and telephone lines, trees and even television towers! Highways and other roads become impossible to travel on, with walking not much of an option either.

Freezing rain starts out as nothing more than good, old fashioned rain; liquid water in a warm (above freezing) layer high above the Earth. The rain begins to fall, and here’s where the twist comes into play: the rain falls through a layer of air that is sub-freezing. This allows the liquid drops to “supercool”, whereby water remains in liquid form, yet below the freezing point. When these liquid drops finally fall to the surface, they smash into the ground or other surfaces (such as cars, mailboxes, telephone poles, roads, trees and anything else obstructing the dirt) and freeze on contact. This collision and subsequent freezing causes the coating of ice otherwise known as a glaze of ice.

The Midwest and the Northeast are prime areas for ice storms, where 12 to 15 ice storms occur on average each year. While freezing rain can take place anytime between November and April, the majority of events occur during December and January. Urban areas tend to take the most damage from freezing rain events, simply because of the population density. Along with the people come the aircraft, trains and personal vehicles, as well as more power lines and utility poles. On top of that, tree branches which ice over can collapse, damaging or injuring anything or anyone unfortunate enough to be underneath a falling branch.

A quarter inch of ice will fully glaze the roads and cripple travel prospects, as well as bring down trees and cause power outages. Any strong winds during the storms only worsen the effects, dislodging any already-weakened branches and power lines.

When an ice storm is forecast, take early preparations like you would for any other winter storm. Travel may be literally impossible, so make sure you have enough provisions in the house to last you at least three days. As always, follow any and all official guidance and warnings to best protect yourself, and stay ahead of the weather with your trusty WeatherBug app.

Credit: NWS, Purdue.edu
-----
Story Image via Pixabay.com