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.
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 neighbor 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.