A new application for satellite altimetry is showcased in this paper. Altimetric satellites are originally intended for oceanographic application through their sea surface height measurement. A different perspective is used here, in which the altimetric satellites are utilised for atmospheric measurement using their microwave radiometer. This paper showcases that the radiometer measurement can be used to study the water vapour variability over the tropical Indian Ocean, which can contribute to the rainfall-induced disaster risk assessment around the region.

The transition into northern Australia’s dry season marks an important time for beef and sheep producers with regard to decisions on animal feed rationing. The last wet season rains – known as the northern rainfall retreat date – could be a useful decision date for northern graziers. This study describes different ways of defining the rainfall retreat and shows that the Australian Bureau of Meteorology’s seasonal forecast system (ACCESS-S2) has moderate skill at forecasting if the retreat is likely to be later or earlier than usual at a lead time of 2.5 months across the far northern wet tropics.