The jetstream has been fragmented and weak across Europe over the past week or so, lowering the chances of organized thunderstorms. On the other hand, such environments favour slowly moving storm clusters and virtually stationary pulse thunderstorms. Such thunderstorms can produce short and intense rainfall or even prolonged intense rainfall, in case of a slow moving cluster. Flash flooding is a major threat with these thunderstorms. Over the past week, several places in Europe experienced intense flash floods as results of short, but intense rainfall.
Arlberg, Tyrol, west Austria
Intense flash floods hit Schann, Arlberg, Tyrol in west Austria.
Val Ferret, southwest Switzerland
Destructive flash flood torrent in Val Ferret, southwest Switzerland on August 1.
Reports indicate well over 100 mm of rain fell in approximately 2 hours and caused this major flash flood in Žagubici, Serbia.