The 1984 Soviet Union tornado outbreak, also known as the 1984 Ivanovo tornado outbreak, was one of only three disastrous tornado outbreaks in modern Russian history (one of the others being the 1904 Moscow tornado) and the third-deadliest tornado outbreak in European history. Occurring on June 9, 1984, the outbreak struck the Ivanovo and Yaroslavl regions north of Moscow, an area over 400,000 km2. At least two of the eleven known tornadoes were violent events, equal to F4 or higher in intensity on the Fujita scale, based upon observed damages. The main tornado, an F4 in Ivanovo, which was up to 1,130 metres (0.70 mi) wide, caused extreme damage, throwing heavy objects of 50,000 kilograms (110,000 lb) for distances up to 200 metres (0.12 mi). Another tornado, assessed to have been at least