CETOSS - A collaborative editing tool for meteorological data based on open source software

The increase of frequency and intensity of extreme weather events requires measures for effective protection from these consequences of climate change. The protection from extreme weather events requires the precise and immedi-ate prediction of this danger. Even though there are elaborated prognosis systems to predict the occurrence of a dan-gerous weather situation like thunderstorms, usually their forecasts need to be revised by experts. To revise a high number of thunderstorm forecasts within and for a very short period of time (nowcast) with high quality is an impor-tant challenge. This paper presents a tool for collaborative editing of such meteorological data which is part of a me-teorological early warning system. Visual representation of automatically generated thunderstorm forecas ts can be edited collaboratively, very quickly and fail-safe. Experiences with open source software development are discussed.