Why were the roads so icy this morning?

This morning’s icy commute was a byproduct of the past few days’ rain, and today’s very light precipitation falling into sub-freezing temperatures.

For most of this winter, significant winter events have been preceded by very cold temperatures with little precipitation leading up to the event. This gave road crews ample time to pre-treat roads--and that treatment wouldn’t wash away.

Even after snowy events were done, salt treatment stayed on road surfaces, and minor snow flurries or snow showers would quickly melt on contact, even if temperatures were well below freezing.

Over the past few days, over a half an inch of rain has washed away any previous treatment that had coated most of the roadways. Without treatment, roads will freeze at much higher temperatures than with salt treatment.

Temperatures dropped into the upper 20s for most locations this morning, and a quick burst of snow from a weak line of snow flurries added a quick layer of snow cover to most of the Indianapolis metro.

Light drizzle or a fine mist added insult to injury with glazing becoming a concern through mid-morning. With temperatures hovering near 30, almost all roads would be icy, until crews could retreat.

Highs should be able to get above freezing briefly this afternoon, but lows tonight will bring temperatures back into the mid 20s. Luckily, drier air moves in tonight, and that should aid in improving road conditions.

Temperatures are set to warm up over the next few days, with 50s expected by Friday.