Early Warning

An EF2 wedge tornado is shown on the ground near the town of Early in northwest Iowa around 9:00 PM, Saturday, April 9, 2011. This view looks north from along Lee Avenue just north of US Highway 20 and about 2.25 miles SE of Early. The image is a video frame capture, seen courtesy of a lightning flash in pitch darkness, and therefore is of poor quality. It has been electronically enhanced to bring out brightness. As our storm chase team proceeded northeast from this location, we encountered our final tornado--another wedge just west of Nemaha, Iowa--around ten minutes later. We found ourselves a little too close to that one and just escaped being in its outer fringe, speeding away from it through driving rain and golf ball size hail. The overall chase produced a least a half dozen tornadoes viewed. *** The "F"-scale was introduced by Dr. Tetsuya "Ted" Fujita in 1971. In 2007 a new scale, Enhanced Fujita (EF), became operational. The old F-scale related the degree of damage to the strength of the wind but did not take into account the typical strengths and weaknesses of different types of building construction, which would become the measure of the new EF-scale. An EF2 tornado typically produces wind speeds up to 135 mph.