Variations of thunderstorm cloud-top parameters are examined using high temporal frequency satellite digital data. The day chosen as a case study, 5 May 1977, featured an extensive severe weather outbreak and was part of the Research Rapid Scan Day program during which three-minute interval satellite data was collected from GOES-1. Overshooting top heights, measured by a shadow casting method, are added to infrared-determined heights and compared to radar echo top ...