Vilhelm Friman Koren Bjerknes ForMemRS (/ˈvɪlhɛlm ˈbjɜːrknɪs/; 14 March 1862 – 9 April 1951) was a Norwegian physicist and meteorologist who did much to found the modern practice of weather forecasting. He formulated the primitive equations that are still in use in numerical weather prediction and climate modeling, and he developed the so-called Bergen School of Meteorology, which was successful in advancing weather prediction and meteorology in the early 20th century.