To calculate the flood forecasts EFAS and GloFAS need the hydrological initial conditions for LISFLOOD which are derived from forcing LISFLOOD with gridded, near real-time meteorological (proxy) observations. They include total precipitation, 2-metre temperature, 2-metre dew temperature, 10-metre U wind component, 10-metre V wind component, surface solar radiation downwards, surface thermal radiation. Reference values of evapotranspiration is derived from meteorological forcing according to the Penmann-Monteith equation implemented in the open source pre-processor LISVAP.
For EFAS, these are based from a large-number of in-situ meteorological data from various data providers, collected, quality checked and interpolated to a regular grid by CEMS MDCC before being transferred to COMP.
For GloFAS, they are based on the Copernicus Climate Change Service atmospheric reanalysis, ERA5 and its timely component, ERA5T. The meteorological variables are upsampled using an interpolation algorithm from the open-source pre-processor pyg2p from their native resolution to 0.05 degrees resolution using bilinear interpolation from GloFAS v4, and the nearest neighbour interpolation was used for 0.1 degrees GloFAS set up (v3 and preceding versions).
More detailed information on EFAS meteorological forcing can be found in EFAS Meteorological observation maps.