“It must have been a tornado” is a phrase often exclaimed as people first inspect severe storm wind damage. Then, if the meteorological storm survey concludes that it was, in fact, not a tornado that caused this damage, there will still be people who will firmly believe that “it must have been a tornado.” The feeling that only a tornado can tear off roofs and tip over train cars is based on inexperience. In fact, when a tornado tears off roofs and tips over train cars, it is merely the force of the wind doing the damage. Microbursts are certainly capable of producing wind gusts in excess of 100 mph which is similar to that in a tornado with an EF1 or EF2 rating, but tornadoes and straight line winds produce different damage signatures. In the case of the Grand Forks storm Sunday night, wind damage consistent with straight line winds corroborated well with Doppler data. There was no tornado.
