50 litres of rainfall per square metre are expected in parts of the country, more than in the historic 1997 flood which killed 100 people across central Europe.
A firefighter died in a rescue operation in a cellar in Austria as the region of Lower Austria declared a state of emergency.
“We are experiencing difficult, dramatic hours in Lower Austria,” said Johanna Mikl-Leitner, Governor of the region.
“For many Lower Austrians, these will be the hardest hours of their lives”.
“We will do everything we can to stand up to the water to protect the land and its people.” A Black Hawk helicopter was deployed to rescue two trapped motorists near Markersdorf.