The Federal Emergency Management Agency is warning drivers across northern Illinois to stay off the roads due to the area’s first ice storm warning since 2009.

“Stay inside and off the roads unless absolutely necessary,” said FEMA Regional Administrator James K. Joseph in a statement. “Monitor local weather alerts and make sure everyone in your family knows what to do now to stay safe in the event of an extended power outage.”

Upwards of .4″ of an inch of ice is expected to coat roads across northern Illinois between late Tuesday afternoon into early Wednesday morning.

FEMA also says the ice could cause power outages and downed trees as the ice accumulates on lines and branches.

More freezing rain and a potentially hazardous wintery mix is possible through Thursday afternoon.