ABSTRACT
This chapter links cloud with rainfall. Raindrops develop in warm clouds through collisions of larger with smaller cloud droplets. The process is sometimes called accretion or collection. Raindrops are created relatively quickly in a cold cloud, because ice crystals develop rapidly amongst supercooled droplets by means of the Bergeron—Findeisen process. The various kinds of rainfall can be classified in various ways. For instance, according to either the intensity of precipitation, the intensity of uplift, or the mechanism of cloud formation. As regards classification in terms of the intensity of uplift, there are 'convective' and 'strati-form' rainfalls. Alternatively, rainfalls can be classified in terms of the mechanism of uplift. Thus there is orographic, frontal and convergence rainfall. These are events of convective rainfall and, of course, thunder. Thunderstorms are due to deep convection within cumulonimbus clouds, releasing static instability within at least 3 km depth of the atmosphere. Lightning results from every thunderstorm containing cold clouds.
