Properly predicting the rapid transition from shallow to precipitating
atmospheric convection within a diurnal cycle over land is of great
importance for both weather prediction and climate projections. In this
work, we consider that a cumulus cloud is formed due to the transport of
water mass by multiple updrafts during its life-time. Cumulus clouds
then locally create favorable conditions for the subsequent convective
updrafts to reach higher altitudes, leading to deeper precipitating
convection. This mechanism is amplified by the cold pools formed by the
evaporation of precipitation in the sub-cloud layer. Based on this
conceptual view of cloud-cloud interactions which goes beyond the one
cloud equals one-plume picture, it is argued that precipitating clouds
may act as predators that prey on the total cloud population, such that
the rapid shallow-to-deep transition can be modeled as a simple
predator-prey system. This conceptual model is validated by comparing
solutions of the Lotka-Volterra system of equations to results obtained
using a high-resolution large-eddy simulation model. Moreover, we argue
that the complete diurnal cycle of deep convection can be seen as a
predator-prey system with varying food supply for the prey. Finally, we
suggest that the present model can be applied to weather and climate
models, which may lead to improved representations of the transition
from shallow to precipitating continental convection.