CHARLOTTE, N.C. — When there are freezing rain events in the forecast, often you’ll hear the WCNC Charlotte Weather Team talk about two things: black ice and encouraging our viewers to be especially careful on bridges and overpasses.
Bridges and overpasses ice over quicker than regular roadways because most roads lose heat evenly. This is because most normal roads have the ground to help insulate them.
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However, with bridges and overpasses, the cold air can reach both above and below the surface. This wraps the bridge or overpass with cold air like a freezing blanket!
This results in a much quicker heat loss. For example, the temperature of a roadway may be 35 degrees while the temperature of a bridge is 30 degrees. And because the cold air wraps the bridge or overpass around with all of that cold air, it also typically stays much colder longer.
What is black ice?
Black ice is a thin layer of transparent ice. The reason why it’s called black ice is because that’s the color of the road pavement it forms on. Because the pavement is transparent, it blends in and you cannot see it, making it especially hazardous for driving conditions.
Black ice also reflects the sun and doesn’t absorb solar energy, so it cannot evaporate on its own.
Contact Brittany Van Voorhees at bvanvoorhe@wcnc.com and follow her on Facebook, X and Instagram.