First snowflakes of the season possible Friday across northern Illinois

A downturn in the temperatures will likely bring northern Illinois’ first snow flakes of the season Friday ahead of a weekend that is expected to be cold and windy.

A cold front is approaching from the northeast, and with it, will come cold temperatures and several chances of a precipitation, said meteorologist Lee Carlaw, who is based at the National Weather Service in Chicago area office.

After temperatures rose into the 60s during the first half of the week, Carlaw said, the region is in for a “pretty abrupt change” in weather, which could include snow.

“Friday looks like we may struggle to get out of the 30s,” Carlaw said. “There’s a fairly good potential for precipitation to change over to snow showers Friday.”

A cold front will bring rain and even a thunderstorm on Thursday, along with windy conditions and falling temperatures. Snow showers will likely follow Friday on the backside of the cold front as the storm system moves through.

Any significant accumulation is unlikely, Carlaw said. Ground and air temperatures will likely be too warm to support accumulation, however, a heavier snow shower west of Chicago could produce a light dusting on grassy areas. The snow may also fall as graupel, which looks like pellets, similar to Dippin’ Dots, Carlaw said.

“It’s definitely a rude awakening, the flood gates to winter opening up,” Carlaw said.

The weekend will be more of the same temperature wise, Carlaw said, with temperatures in the upper 30s to low 40s Saturday and Sunday. Chances for snowflakes are lower, however.

This snowfall would typical for the region timing wise.

“Around Halloween we tend to see our first trace of snow. Right about now or next week or so is the time we see our first accumulating snow,” Carlaw said.

A trace of snow is when snow accumulates in a dusting of less than a tenth of an inch, while a snowfall counts as an accumulation when a tenth of an inch or more has fallen, Carlaw said.