meteorology

Australia’s Bureau of Meteorology has also warned that the volcanic ash might drift to parts of the country's north on Wednesday.

Virgin Australia, which cancelled all its flights to and from Bali on Wednesday, said in a statement: “Safety is always our highest priority, and our meteorology team is closely monitoring the situation.”

Lalas spent a formulative part of his childhood in Greece, where his father, Demetrius, a professor of mechanical engineering and meteorology, was director of the national observatory in Athens.

“Experts have talked about an absolutely unprecedented situation,” he said, citing the “abrupt nature of meteorology”.

The Polish Institute of Meteorology and Water Management later extended the highest alert level from the four southern provinces to the mouth of the River Odra in Szczecin, where it spills into the Baltic Sea.