Cold downdrafts in cumulonimbus clouds

ABSTRACT The mechanism of maintenance of cold steady downdrafts in convective clouds is investigated in a numerical experiment using a one‐dimensional steady state model of the updraft‐downdraft interaction. It is established that usually the downdraft cannot be effectively chilled unless it is fed with small droplets from the updraft by at least two simultaneously acting mechanisms: entrainment of the updraft air and fallout of drizzle‐size droplets through the inclined updraft‐downdraft interface.