At a Washington meeting of the American Meteorological Society last week, Glenn E. Stout of the Illinois State Water Survey showed the first radar movie of a full-grown tornado roaring across the prairie (see cuts).
The radarmen of the Water Survey first focused on a thundercloud which had suddenly grown a tail (the large blob of light near top in first cut). This was the start of the tornado funnel, still high in the air and shooting toward the east at about 48 m.p.h.
Eight minutes later, the funnel had curled into a thin spiral, with its tip dipping down to the ground...