Within EFAS the LISFLOOD hydrological model is run as a continuous simulation using interpolated observed meteorological data. This simulation provides the initial conditions for the EFAS forecasts. The simulated soil moisture is taken from the upper soil layer of the model. It can be provided either as a volume or as an anomaly calculated using the long term average (m) and standard deviation (s) of the soil moisture on that calendar day as
where X is the simulated soil moisture. The long term average and standard deviation are taken from a 22 year simulation of LISFLOOD.