Georgia DOT: Why 2 inches of snow is sometimes harder to plow than 12 inches

Curtis Compton/ccompton@ajc.com

Credit: David Wickert

Credit: David Wickert

Curtis Compton/ccompton@ajc.com

One storm dumped up to 12 inches of snow on parts of metro Atlanta, and most highways were cleared in a few hours.

The other blanketed the region in about 2 inches of snow, and some highways remained icy 24 hours later.

The Georgia Department of Transportation says this Tale of Two Atlanta Snowstorms – one in December, the other this week – shows weather conditions have a big impact on its efforts to keep highways clear.

On its face, the December storm that dumped 12 inches of snow on parts of Cobb County would seem to be a tougher assignment than this week's storm. But GDOT spokeswoman Natalie Dale said that's not so.

For starters, the December snow was wet and heavy – and easily plowed. But the snow that fell this week was dry. Dale likened it to “plowing sawdust.”

“It just blows back up in the air and falls back on the road,” she said.

Temperature also was a factor. In December, temperatures were barely below freezing when the storm hit and rose above freezing the next day.

This week, Atlanta hasn’t’ seen temperatures above freezing since before the storm hit. That meant snow froze on highways as it fell and was covered by more snow, Dale said, making it difficult to keep the roads clear.

Despite the challenges, Dale said GDOT crews did a good job of clearing roads Wednesday even though the snow didn’t stop in some areas until mid-morning. It used salt and gravel to break up ice and brine to prevent the roads from refreezing. Afternoon sun and wind also helped.

“In one 12-hour shift yesterday, we were able to get all interstates passable and most state routes in good shape,” she said.

The moral of the story, Dale said: “They were two very different storms. If we have another one, it will be different again.”