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.
Both EFAS and GloFAS require total precipitation. Data availability defines the list of the remaining meteorological forcings. Specifically, EFAS makes use of minimum and maximum temperature, average wind speed, surface solar radiation downwards, and water vapour pressure; GloFAS makes use of 2-metre dew temperature, 10-metre V wind component, surface solar radiation downwards, surface thermal radiation. For both EFAS and GloFAS, reference values of evapotranspiration are derived from the meteorological forcings according to the Penmann-Monteith equation, as implemented in the open-source pre-processor LISVAP.
For EFAS, the meteorological observation maps 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 Meteorological Data Collection Centre. The observation dataset and the quality checks are presented into details in the Annual Reports of the CEMS Meteorological Data Collection Centre. The gridded dataset is therefore constantly updated, it is available for download from the European Commission Joint Research Centre Data Catalogue. More detailed information on EFAS meteorological forcing can be found in EFAS Meteorological observation maps.
For GloFAS, the meteorological proxy observation maps are based on the Copernicus Climate Change Service atmospheric reanalysis, ERA5 and its timely component, ERA5T. The pre-processing and interpolation from native resolution to the desired resolution is described in this page.