The animation below shows Infrared Satellite Imagery which detects the temperatures of the cloud tops or the surface. For example, cirrus clouds can be seen across portions of Indiana, Ohio, and Kentucky this evening where the satellite depicts temperatures colder than -50C (red and pink colors). You might also notice the expansive area of yellow moving south across Manitoba, Ontario and Quebec. Most of this area is actually cloud free. This is a cold arctic airmass with temperatures of -30C indicated at the leading edge of yellow hues advancing south across Canada to near Lake Superior. Surface observations across southern Ontario confirm temperatures of -20F or colder that the satellite imagery is depicting. Here in northern Illinois and northwest Indiana, we will only get a glancing blow of these colder temperatures. Friday, expect the morning lows in the single digits to mid teens across our outlook area.