Ice storms are described as occasions when damaging accumulations of ice occur during freezing rain situations. The terms freezing rain and freezing drizzle warn the public that a coating of ice is expected on the ground and on other exposed surfaces. Heavy accumulations of ice can bring down trees, electrical wires, telephone poles and lines, and communication towers.
Communications and power can be disrupted for days while utility companies work to repair the extensive damage. Ice forming on exposed objects generally ranges from a thin glaze to coatings approximately one inch thick. Even small accumulations of ice on sidewalks, streets, and highways may cause extreme hazards to St. Louis County motorists and pedestrians.
Sleet does not stick to trees and wires; however, sleet in sufficient depth does cause hazardous driving conditions. Heavy sleet is a relatively rare event, defined as an accumulation of ice pellets covering the ground to a depth of ½¬inch or more.
Ice and sleet storms occur from October through April. According to statistics maintained by the National Climatic Data Center (NCDC), in St. Louis County, freezing rain and freezing drizzle events occur on average of at least one day per year. The month of March has, on average, the greatest number of days in which freezing rain and freezing drizzle occurs.
The National Weather Service (NWS) notes that over 85-percent of all ice storm deaths are traffic related.