DIONYSOS is a diagnostic software especially build to analyze, interpret and understand numerical weather model forecasts output, from mesoscale to large scale. Including a complete set of diagnostic equations, it enables to separate quantitatively different physic and dynamic processes effects on several important meteorological fields, such as vertical motion, divergence, local tendencies of vorticity, geostrophic vorticity, temperature, geopotential height and mean sea-level pressure. These important physic and dynamic processes are vorticity advection, temperature advection, latent and sensible heating, friction and orography. To run DIONYSOS, it requires only standard operational numerical weather forecast model output, so that it can run on most existing numerical models. This independency from a particular numerical model is possible by the development of a few simple parametrisation methods (that only uses operational standard numerical model output) to compute some meteorological fields needed by the diagnostic equations, but generally not available from standard numerical model output: latent and sensible heating, friction and orography.
DIONYSOS applications are numerous in operational forecast field and in atmospheric sciences researchs. With the different meteorological fields partitions it does, DIONYSOS is a practical tool to interpret, inter-compare and verify numerical weather forecast models in a synoptic or dynamic scope, either in realtime or in a retrospective way. Currently, DIONYSOS is used operationally at the Canadian Meteorological Centre (CMC) in Montreal. It is also used at Université du Québec à Montréal (UQAM) and at Wageningen University (Netherlands) for different research projects or in a pedagogical context.