fayetteville, arkansas, already, triggering a dangerous commute. and look at this along the i-95 corridor. crews out salting the roads. this is bucks county, pennsylvania, bracing for black ice to come after snow already today. and by tomorrow morning, the wind chill will be near zero in philadelphia and new york, 4 below zero in boston. senior meteorologist rob marciano leading us off tonight timing this all out for us. reporter: hi, david. you said it right there. the cold is going to be the most debilitating debilitating, widespread element of all of this, with half the country seeing temperatures 15 to 30 degrees below average. look at pittsburgh, minus 1. 3 in chill. minus 1 in st. louis. minus 24 in des moines. this sets the stage for icing across the south. in texas t, we have winter stor warnings from brownsville, texas, to virginia beach. moisture into the sub-freezing air, so, significant icing in