The Role of Environmental Humidity in the Moisture Budget of Thunderstorms

As such, the moisture budget of individual thunderstorms is of interest. Observational studies (Braham 1952; Foote and Fankhauser 1973; Fankhauser 1988; Heymsfield and Miller 1988) have great uncertainty associated with them because of the difficulties of measuring, or even estimating relatively accurately, both the input of water vapor and the output rainfall of a storm. Numerical modeling (Weisman and Klemp 1982; Brooks and Wilhelmson 1992) has addressed the issue as a small part of studies on the behavior of thunderstorms, particularly severe thunderstorms. Here, we consider the moisture budget of “ordinary” thunderstorms in environments with modest potential instability and little or no vertical wind shear. In particular, we focus on the role of environmental humidity above cloud base. The results presented here represent only the beginning of a more complete investigation of the impact of environmental conditions on the moisture budget of thunderstorms.