Jurgen Steppeler studied mathematical Phzsics, solid state Phzsics and particle phzsics in Goettiongen. After finishinng hos studies with a PHD in Goettingen, he joined the german Weather service in Offenback (DWD) as a specialist for mathematical methods. Research visits of a total of more than 10 years led hom to the USA, ECMWF, UK, and `China. He was project manager for the development of the nonhydrostatic model of DWD. This means that that no approximations specific to meteorology are made. Together with Johm Baumgardner, Los Alamos he pioneered tha use of polygonal grids on the sphere. These are grids derived bz inscibing platonic or semi platonic solids into the sphere. He showed that the cut cell technique to describe mountains leads to a significant increase of forecast quality.