More and more European countries are developing policies to release their data as so-called Open Data. Open Data refers to information that can be freely used, modified, and shared by anyone for any purpose. In this context, also a number of National Meteorological Services are adopting an Open Data policy. Examples range from the Finnish Meteorological Institute (FMI) launching its Open Data online service already in May 2013, to a more recent member of the “Open Data Club”, the German National Weather Service (DWD). The range of spatial data offered on such Open Data services is wide and can include model forecasts, radar data, current measurements and observations, a large amount of different types of climate data and many more. In some cases the data sets are additionally available via GeoWebServices, e.g. in OGC compatible WMS and WFS formats.

Besides those "classical" Open Data, more and more efforts are also devoted towards the use and integration of datasets obtained via crowdsourcing methods. Such crowdsourced observations can be used in a variety of applications, e.g. as input for numerical models / data assimilation systems or as viable source of information for impact modelling activities.

The session invites contributions on both technical and user focused developments related to providing and using these freely available datasets. This includes amongst others:
• The development of client applications based on Open Data
• New ideas where and how Open Data can serve society
• The development of user friendly geoportals including
o Catalogue services
o Download services
o Visualization services
o Transformation services
• Tools and interfaces (APIs) for utilizing Open Data
• Opportunities and challenges regarding Crowdsourced Data
o data sources, data fomats, legal issues...

The aim of the session is to bring together the provider and current/future user of Open Data portals and crowdsourced data across Europe, to share their experiences and requirements.