On October 11, 1989, Joseph Tribbia and Phillip D. Thompson interviewed Arnt Eliassen for the American Meteorological Society’s Tape Recorded Interview Project at Thompson’s residence. Eliassen recounts his early influences in meteorology, starting with seminars led by Vilhelm Bjerknes in 1938 that sparked his interest in the field, and his subsequent studies under Halvor Solberg. He details his academic path, including completing his master’s degree in 1941 during the German occupation of Norway. Eliassen describes how, despite wartime constraints, he engaged in meteorological studies and collaborated on coded communications supporting the resistance. Eliassen reflects on his work in numerical weather prediction, explaining his early post-war contributions to geostrophic methods and theoretical advancements, including his development of a quasi-geostrophic system. He shares insights into his interactions with prominent figures, such as Jule Charney and John von Neumann, during his time with the Meteorology Project at the Institute for Advanced Study in Princeton. Eliassen notes the challenges of cross-language collaboration and describes the formative period when numerical weather prediction evolved from theoretical possibilities to practical application. The interview also highlights the influence of key publications and the evolution of meteorological thought, with Eliassen referencing the works of predecessors like V. Bjerknes and contemporaries such as Rossby. He recounts his contributions to using pressure coordinates in prediction models and reflects on his broader career and the academic culture of meteorology in Norway and beyond.