An ice storm is made up of freezing rain, which is a form of precipitation composed of rain that turns into ice upon contact with the ground. This kind of storm usually occurs when the ground is cold enough for ice, but the air is still warm enough for rain. There can be severe damage resulting from the force inflicted by ice storms, this damage includes damaged trees, dwellings, and high-tension cables. In 1998, a severe ice storm hit a large region of southeastern Ontario, southwestern Quebec, and upstate New York. Montreal was hit the hardest, with large areas of the city being deprived of power for more than a week. Almost a third of the trees in Mount Royal Park had to be felled, and forests, especially the economically important production of maple sugar in the region in particular, were devastated. Sleet forms along with ice storms. Sleet forms as a result of snow melting and then refreezes before hitting the ground. It consists of small pellets of ice that bounce and make tapping sounds when they hit the ground. The interior of the pellet can be partially liquid and therefore might break upon hitting a hard surface. The ice pellets are transparent, irregular or globular grains of ice. The weight of this ice is great enough that it can snap power lines, break tree limbs, and sometimes even bring down whole trees. Sleet is less damaging, though it has, on occasion, brought down a few power lines. People are strongly encouraged not to walk and drive during ice storms, as the accumulation of the ice on the ground can result in serious injuries. The National Weather Service suggests that people keep a certain supplies around their houses incase an ice storm occurs. These supplies include: a flashlight and extra batteries, a battery-powered NOAA Weather Radio and portable radio, extra food and water, extra medicine and baby items, first aid supplies, heating fuel, emergency heating source and a fire extinguisher and smoke detector.
The first picture is of ice on a tree branch after an ice storm has taken place, courtesy of http://www.photoquest.com/jmimages/ice.jpg The second picture is of a birch tree that has been damaged by an ice storm, courtesy of http://www.noble.org/Press_Release/Ag/IceDamage2000/