Frontogenesis and cross frontal circulation in a strong summertime cold front

Summary The characteristics of a strong European summertime cold front are investigated using the wealth of synoptic observations, which were analysed by the dynamical initialization scheme of an operational meso-scale model. The study was also extended to forecasted fields.Cross-sections perpendicular to the front, covering a dormain of more than 2000 km in the horizontal and 10 km in the vertical direction, bring out the basic parameters (as potential temperature and the components of the geostrophic and ageostrophic wind vectors), the ageostrophic crossfrontal circulation and all cross-frontal frontogenesis terms.None of the many frontogenesis terms plays a dominant role, there is a concerted action of geostrophic and ageostrophic deformation and shear, of tilting and diabatic sources in producing a rather complex structure of total frontogenesis. The cross-sectional fields of all presented terms strongly underline the fact, that a front is not a line of discontinuity but a rather wide three-dimensional field phenomenon.With 12 Figures