Forecasting daily reference evapotranspiration for Australia using numerical weather prediction outputs

Abstract

Farmers and irrigation system operators make real-time irrigation decisions based on a range of factors including short-term weather forecasts of rainfall and temperature. The simplest and oldest statistical method for forecasting daily ET is to use the long-term monthly mean ET based on historical observations. Forecasts of reference crop evapotranspiration (ET ) can be calculated from Numerical Weather Prediction (NWP) outputs and ET has the advantage of being more directly relevant to crop water requirements than temperature. This paper evaluates forecasts of ET made using the Bureau of Meteorology's operational NWP forecasts derived from the Australian Community Climate and Earth Sys..