"What's unusual about this storm is that it will affect the whole country and not just certain zones," said Christoph Hartmann, a spokesman for the DWD in Offenbach.

The northwest of Germany would be the first to feel the full impact of Kyrill from early afternoon, before the storm swept across the rest of the country and moved eastwards into Poland, the Czech Republic and northern Austria, the DWD said.

Rain would likely continue into the weekend in affected areas, as the storm's force gradually dissipated, it added.

As Germans were warned on the radio and television to keep their cars away from trees and to stay indoors, authorities in states stretching across the length and breadth of the country said many schools were closing early due to Kyrill's arrival.

Rescue services around Germany said they had mobilized extra staff to prepare for potential flooding and destructive winds.

German airline Deutsche Lufthansa said it expected numerous flight cancellations and delays on Thursday, while Frankfurt airport said takeoffs and landings were cut by half.