Doppler Radar Observations of a Mountain Hailstorm

By means of an X-band, vertically pointing Doppler radar observations were made of a thunderstorm on 20 August 1973 producing hail about 6 mm in diameter.The observations confirm earlier ones showing a highly variable internal structure.Updrafts are composed of high velocity "eddies" having diameters of about a few 100 m to a kilometer.It is speculated that such hailstorm features as the size and layering of ice type and the sporadic nature of hail showers are explained by the highly variable character of each updraft region and the sequence, at periods of 3 to 4 minutes, of updraft formation.