A server system 150 for providing data to at least one mobile device 200, the server system comprising a processing resource 174. In a first embodiment, the processing resource 174 is configured to generate contour data representing a boundary of a respective area for which a weather-related parameter has substantially the same value, the contour data being sent to a mobile device 200. In a second embodiment, the processing resource 174 is configured to determine a plurality of parameter values of a model representative of weather-related data, and to filter the parameter values such that only some of the values of sent to a mobile device 200.