Organisation of convective clouds in the tropics can not only be observed from satellites or radars, but is also seen in high-resolution numerical models. Understanding convective organisation is important because changes to it under global warming might trigger radiative feedbacks and it also plays a role in the distribution of precipitation.

Yet still missing are metrics to quantify the state of organisation, necessary for further analysis of it. For application to satellite observations or large-scale model data, there have been a few metrics proposed, however they have shortcomings when applying them to radar data. Also they do not take into account the size and shape of the convective objects.

Here we show first steps towards a metric of convective organisation based on multiple years of radar observation. The metric takes into account the different sizes of the objects and aims to incorporate their shape as well. This metric is needed for further studies that will determine large-scale processes influencing  the different states of convective organisation.