The aim of this proposal is to exploit the added value of GNSS tropospheric product for the nowcasting of convective storm and fog by building demonstrators in support of public weather and hail suppression services in Bulgaria. The convective Storm Demonstrator (Storm Demo) will be based on GNSS derived tropospheric products (IWV) and Instability Indices (II) to derive site-specific threshold values integrated and updated in real-time on a public geoportal. The demonstrator targets development of service centered at GNSS products for two regions with hail suppression operations in Northwestern and Central Bulgaria. This service will be unique in Europe and will serve as a prototype for the real-time provision of GNSS products for storm nowcasting. The Fog Demonstrator (Fog Demo) will use GNSS tropospheric products and stability index developed for the capital of Bulgaria, Sofia. Sofia is located in a valley surrounded by mountains and during the cold part of the year fog is a common phenomenon resulting in poor air quality and traffic chaos. The fog site-specific thresholds will be developed and integrated on a publicly accessible geoportal providing a new data stream for National Weather Service but also for public services operated by the Sofia municipality.