A method for providing environmental data to a vehicle such as an aircraft is provided. The method includes receiving a request from a vehicle to provide environmental data, and defining a route plan vicinity area as a part of a coverage polygon. The method further includes receiving alternate/back-up destinations selected from a list and defining and including in the coverage polygon one or more connection areas between the route plan vicinity area and the selected alternate/back-up destinations. The method smooths the coverage polygon and assembles environmental data for the smoothed coverage polygon. The assembled environmental data is sent to the vehicle.