Assessing environmental actions from modern meteorology

This paper gives an overview of current achievements where modern weather forecasting techniques are implemented for the assessment of especially ice and wind loadings on electrical overhead lines, TV towers, masts and similar infrastructure. Modern numerical weather prediction models (NWP ) incorporate far more details on e.g. cloud physics and dynamics than those generally necessary for regular weather forecasts. Such models describe in principle all physical and dynamical processes in the atmosphere in 3-D. In combination with detailed data on the physical properties of land and water surfaces, it is now possible to obtain realistic values of weather parameters related to wind, turbulence, precipitation and atmospheric icing down to a horizontal scale of a few hundred meters. Such models are therefore powerful tools for the planning and final design for various infrastructures in remote terrain where little or no weather data can provide sufficient bases for the establishment of extreme weather loads necessary for their design