Science Behind The Sheet Of Black Ice Roads In Oklahoma

The roads might look OK, but driving on them is a different story as a light freezing drizzle can turn a bridge into a sheet of black ice.

The roads might look OK, but driving on them is a different story as a light freezing drizzle can turn a bridge into a sheet of black ice.

Arctic air pushed into Oklahoma fast Monday morning, when temperatures plummeted from the mid-30s to below freezing over the span of a few hours. But, mist and drizzle mainly froze on really cold surfaces, such as bridges, overpasses and shaded areas.

On Monday afternoon, KOCO 5 took the ground temperature in Oklahoma City. It hovered around 30 degrees, and that road temperature is key.

The actual road, whether it’s asphalt or concrete, isn’t really icing over because the Earth actually insulates it and keeps it relatively warmer and above 30 degrees. But, there’s nothing keeping bridges warm underneath.

The air moves freely above and below it, cooling it down faster. The cold bridges accumulated thin layers of ice.

It’s a sneaky weather hazard because many people don’t notice it. You could drive like normal, hit a slick spot on a bridge and start doing circles.

Originally published at Koco

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