The surface geometry after laser hybrid arc welding is an important quality criterion. What isoften called welding in a rough industrial environment can in many cases systematically bereduced to a few local conditions of the joint edge during welding, particularly depending onthe edge preparation technique. In the present study, beside the influence of surface oxidesstudied in separate publications, the conditions are reduced to the local gap width, verticalsurface position and edge mismatch. Gas cut edge conditions are compared to milling andlaser cutting. By scanning the steel edges of a 10 mm butt joint before and during hybridwelding and relating the systematic variation of the above three properties to the scannedtopology of the resulting weld, quantitative correlations are identified. By the aid of highspeed imaging, explanations for the trends can be found. Operating windows with controllabletrends can be quantitatively mapped and distinguished from instable regimes. Beside higherroughness, gas cut edges show a superimposed edge oscillation of longer periodicity, beingless visible but important. During welding, concave surface bending and gap widening alterthe initial conditions. Awareness and quantitative identification of the edge conditions isrecommended to control the welding process in a rough industrial environment.