Abstract
An investigation of the effective maximum range of detection of 500-kc./sec. sferies was conducted by examining recorded sferies data from widely separated locations and also during times when a circular area surrounding the detector was devoid of both radar echoes and severe weather events. Sferies were recorded from all severe weather events identified radaras well as severe weather events listed in Storm Data within 200 mi. of the detector. As the range radius of the clear area was increased beyond 200 mi., the number of severe weather events which failed to give detectable sferies pulses increased rapidly.
