Nightly News | May 21, 2013
>> viewers of the weather channel know the name dr. greg forbes . he's the severe weather expert. also a very modest man. what he never tells you is he's responsible for the formulation of these f codes and efs. so when we say this was an ef-5 tornado, this next gentleman, dr. forbes, good to see you -- was part of the formation of those categories. we always talk to you in the studio, but you try to get out in the field as much as you can to see this expulsion of energy. this is about as much energy as nature can produce.
>> it really is. the worst i've personally seen, the spans of the damage, with everything destroyed, then ten miles long with pretty much everything destroyed the worst i've seen.
>> we get questions from viewers and our weather coverage seems to increase in years past people want to know is something up here? is this a new normal? are you noticing any trends?
>> i think the trend really is that our metropolitan areas are getting bigger, so instead of being wee little tiny needles in the haystack for these tornadoes that otherwise could have gone through the fields, now it's harder for them to miss the cities. i think maybe that more than the weather itself is what is changing.
>> but how perverse is it? you and i were around during the '99 storm. how close this track was to that.
>> yeah, and there was another track in 2003 . so some of the same areas have been affected by three tornadoes.
>> of course there's a reason we call it tornado alley .
>> indeed it is. we're right in the heart of it here.
>> dr. greg forbes , a pleasure to have you as part of our team of coverage