Introduction

A Cold Front is passing over Austria. The prefrontal airmass is very unstable. In the morning (06.00 UTC) there are several mature MCSs over Hungary, Slovakia and Poland indicating a strong tendency for convection.

A few hours later convection starts in Austria. The Cbs in the south-eastern part are shown in this case study. Nowcasting tools demonstrate the possibilities for advanced warnings of severe weather events.

Within the unstable prefrontal air, the mature Cb stage is reached in the early afternoon due to diurnal heating. Besides the hail which caused damage in the western and north-western parts, a tornado was also observed. The total amount of rainfall is shown below. It exceeds the average monthly amount.