CARBONDALE, Ill. (AP) — A gusty winter storm slammed southern Illinois on Wednesday, leaving roads covered in ice and snow and prompting authorities to warn of whiteout conditions that could significantly reduce drivers' visibility.

The National Weather Service said 4 inches to a foot of snow had fallen on the region as of Wednesday morning, with the heaviest amounts reported from Anna in Union County northeast to Harrisburg. As much as 3 more inches could fall before the snow is slated to taper off by midday.

WSIU Radio reported that the storm forced the weather service to issue its first-ever blizzard warning for the region. Forecasters said the storm could lead to whiteout conditions and reduce visibility to less than a quarter mile.