Large uncertainties still remain about the mechanisms of genesis and interaction of clouds in a large scale environment. Through a semi‐empirical dynamical model using hourly data from TOGA‐COARE IOP (130E–180E and 15S–15N, 01.11.91–28.02.92), we show that the convective activity leading to clouds is a self‐regulating, threshold process embedded in a large‐scale environment. The convective activity is prescribed through a of hourly fractional cloud cover while the environmental forcings are defined in terms large‐scale moist state defined in terms of the average brightness temperature. A prognostic model is then developed for cloud cover as the dynamical variable. To validate the model we integrate it with a given initial condition from observed data. The model reproduces the observed spatio‐temporal structure of the cloud with a remarkable degree of success. We identify and quantify two thresholds for large‐scale forcing for genesis and intensity of high clouds.