An investigation of the cellular structure of storms using correlation techniques

Abstract

A statistical technique called “full correlation analysis” has been applied to short-time interval rain data for eight intense storms recorded at two raingauge networks set up by the British Meteorological Office. The technique has been used to investigate the cellular structure of the storms. Certain important storm parameters were estimated including the velocity and direction of movement of the surface rainfall pattern, its mean spatial scale and its lifetime. The results of the analysis suggested a typical cell size of the order of 3 × 1.5 km. The velocities and directions of movement of the surface rainfall patterns agreed well with the 700-mbar wind velocities recorded at the time of the storm. The average lifetime of the storm cells varied from 4 to 6 min. at one network to considerably longer periods at the second network. Conclusions are drawn as to the types of storm to which the technique of full correlation analysis can be meaningfully applied and comparisons are made with other methods of analysis of rainfall data.