by friday, it could be 20 degrees belzero. tonight, states are bracing for pockets of record cold. >> we haven't seen anything like this for a while, this early in the season. >> reporter: across much of the west, temperatures could plummet 40 degrees below normal. in denver it went from nearly 60 degrees to 6 in 2001 day, perfect for the polar bear at the zoo, not so ideal for this snowplow. >> you've got icy, snow packed roads. >> reporter: with an army of plows working around the clock, it is all hands on deck to keep the roads clear for the evening commute. in utah, the highways a nightmare. more than 300 accidents today alone. in minnesota at least 175 crashes since midnight. the deep freeze is even crippling california's citrus crop. >> they'll go bitter on you fairly fast if they're frozen hard. >> reporter: 85% of the fruit in this multi-billion industry is still on the trees. they could lose it all in an overnight freeze. >> worst-case scenario, we'll lose about $2 billion worth of product. we'll have unemployment tot