Solutions and problems when applying qualitative and quantitative information from weather radar

Abstract Based on experience made in various Alpine countries, the advantage of radar to grasp the present weather situation is discussed (e.g. for nowcasting purposes). Often, we spend too much effort in discussing sophisticated algorithms for solving special aspects. When aiming to apply radar data in a quantitative way, errors involved (such as shielding, clutter, beam-resolution, attenuation, variability of the Z-R-relationship and calibration) may let us forget the dominant advantage of radar: to tell us in detail when and where something is happening. Of course we should make the best estimate of e.g. the rain arriving at ground level. But for many applications a rough estimate of the precipitation intensity (together with its uncertainty) may already be helpful and more realistic, than to try obtaining the accuracy needed to distinguish a “disastrous” precipitation from “just a strong” one.