Flash floods are among the world’s deadliest natural disasters with more than 5 000 lives lost annually. Their social, economic and environmental impacts are significant. Accounting for approximately 85% of flooding cases, flash floods also have the highest mortality rate among different classes of flooding, including riverine and coastal. Flash floods differ from river floods in their short time scales and occurrence on small spatial scales, which makes flash flood forecasting a different challenge from large-river flood forecasting.
South-East Europe has experienced a significant number of severe meteorological and hydrological events in recent years. Heavy precipitation has caused floods and landslides. Droughts have increased the incidence of forest fires. People have suffered under prolonged heat and cold waves. There have been severe thunderstorms and hailstorms. These natural hazards have had significant impacts: human lives have been lost, property and infrastructure damaged, and the functioning of key sectors impaired.