The flood at Mount Fulufjallet, 30-31 August 1997 was caused by the most furious rainstorm ever documented in Sweden. Private measurements on the mountain show nor less than 276 mm over 24 hours, and the distribution of severe damage suggests even higher amounts in other parts of the mountain. The precipitation was connected to a front attacking a high pressure that had been dominating the weather in Sweden for several weeks, but orographic lifting on the east-facing slopes of the mountain may partly have caused the extreme intensity. In River Fulan. one of the upper branches of River Dalalven, the discharge peaked at a diurnal mean value of 233 m(3)/s, the highest since measurements began in 1913. At the stream Tangan and the new common outlet of the streams Store and Lilla Goljan, both locations with a normal discharge of only around 1 m(3)/s, instantaneous values of approximately 300 m(3)/s have been estimated, corresponding to values close to the normal discharge at the mouth of River Dalalven on the coast of the Sea of Bothnia.