Flash freeze leads to morning crashes in Miami Valley

MIAMI VALLEY — Scattered light snow showers created hazardous travel conditions across the Miami Valley early Thursday morning, but you may be asking why this morning was so much worse than others.

Overnight into Thursday morning, a steady burst of light snow moved into the Miami Valley. The fluffy flakes quickly accumulated on the road and grass. While this has happened before, what made Thursday morning more dangerous was the road temperatures.

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Typical rock salt is effective as long as the pavement temperature is above 15 to 20 degrees Fahrenheit. While road sensors were slightly above this range initially, they dropped quickly once the snow began to fall.

What may have happened was as the snow hit the ground it melted due to the pre-treatment. Then as more snow fell and with a light breeze the wet pavement temperature quickly dropped. This may have created a thin layer of black ice underneath a coating of snow. This is called a “Flash Freeze.”

It’s important to keep this in mind as we continue through the next several days and the chances for snow returns. Until we get a good push of warmer air and melt our snowpack, the ground can quickly collect snow when it falls.