Nightly News | April 17, 2011
>> typically we see an average of 163 tornadoes for the entire month of april. experts say this outbreak produced well over 200 reports of tornadoes over just three days. some of the biggest were caught on camera at the very moment of impact. tonight, veteran storm tracker jim cantori of the weather channel tells us what's behind the potent supercells.
>> reporter: if one tornado isn't bad enough, how about two of them or three of them rotating around each other?
>> oh, my god.
>> reporter: that's what we have going on here. this is tushka, oklahoma. a multivortex koertornado. a parent cone or super cell . two violents rotating tornadoes, sometimes three or four rotating around each other. this just makes a disaster wherever it happens. i don't think i've ever seen an outbreak of tornadoes where more multivortex tornadoes have been actually captured on fim film. this is jackson, mississippi, on day two. the kind of tornado you see rotating there probably has winds of 150 to 200 miles an hour. it could pick up a car. that's the kind of strength we have here with this tornado. it could easily pick up a car and throw it for 100 yards, 200 yards, who knows.
>> not good, guys.
>> reporter: power flashes going off. those are transformers blowing almost continuously. i think what surprises me the most is the number of automobiles still out there on the road. but as that storm worked its way, again, across this overpass, cars just driving, almost completely oblivious to what is probably a tornado that has winds with it of 150 miles an hour or greater.
>> blew the roof off the house.
>> reporter: this is wilson, north carolina . you can see this is probably a little bit closer than you want to be. that's a walgreens right there. look at that. boom. just exploding as that tornado moves right over the top of it. fiberglass, 2 x 4s, everything. what stands out to me the most was the tornado i saw move through raleigh, north carolina , yesterday. you could have seen that storm move through kansas. that's the way it looked structurally from a radar perspective.
>> the weather channel 's jim cantori . jim points out these tornadoes can move at ground speeds up to 50 miles an hour, making them awfully hard to outrun.