Cyclone Debbie appears to have added another blow to the Great Barrier Reef, hammering a region that had escaped the worst of the coral bleaching over the past 15 months, a senior researcher says.

The slow-moving category four tropical storm, which crossed the north Queensland coast on Tuesday afternoon, is likely to have left a trail of extensive damage to reefs in its path, much like Cyclone Yasi in 2011, said David Wachenfeld, director of reef recovery at the Great Barrier Reef Marine Park Authority.

"The primary concern will be the immediate physical damage in that central part of the storm with high wind speeds," Dr Wachenfeld said. "It's had lots of time for the wave energy to be built up by the winds and for that wave energy to hit the tops of the reefs."

Cyclones can be a mixed blessing for corals. While reefs near the storm's centre can be badly damaged, the tempest can also bring much-needed mixing of relatively hot, stagnant waters.