Contents: Thunderstorm turbulence measurements by air-craft and concurrent radar echo evaluations; Investigation of severe storms with pulse Doppler radar; 500-kc./sec. sferics studies in severe storms; Movements and patterns of development of thunderstorms; Some relations between thunderstorm radar echoes and surface wind fields; On vectoring aircraft through thunderstorms; and Analysis of the severe weather factor in automatic control of air route traffic. (Author).