Why does spring thaw cause flooding in northern and eastern Europe?

In northern and eastern Europe, spring flooding is primarily driven by the rapid increase in river discharge resulting from snowmelt and runoff as temperatures rise.12

This process often leads to severe flooding through the formation of ice jams. As spring arrives, rising temperatures and increased water flow break the river ice cover loose from the banks. This ice is then transported downstream until it encounters an obstruction—such as a change in river slope or an intact ice cover—where it accumulates. These jams can become thick enough to block the river's flow, causing water levels to rise rapidly behind them.1

In northern regions, this phenomenon is particularly pronounced in northerly flowing rivers, where upstream ice melts first and moves toward colder, more stable ice downstream, frequently resulting in destructive flooding. Additionally, the sheer volume of water from melting snow contributes to high discharge levels in rivers across these continental climates, making them particularly susceptible to flooding during the spring thaw.12