The La Nina weather phenomenon is to blame for Australia's floods, experts say.

Northern Australia was hit by what was referred to as an "inland tsunami" Tuesday night. In Brisbane, Australia's third largest city and the capital of Queensland, the Brisbane River could reach a record crest of 18 feet Thursday. Of the 2 million people living there, one-third were told to leave their homes.

"The Queensland floods are caused by what is one of the strongest -- if not the strongest -- La Nina events since our records began in the late 19th century," said Monash University Professor Neville Nicholls, who is president of the Australian Meteorological and Oceanographic Society, The Guardian newspaper reports.

La Nina conditions form when cold water in the South Pacific pushes warm waters hard against the east coast of Australia. As a result of the weather patterns, December was the wettest recorded in Queensland and the country experienced its third wettest year.

The Australian Bureau of Meteorology predicts La Nina could continue into March -- when autumn begins in Australia -- and likely will bring more downpours.

There were indications as early as June that a La Nina event was forming, the bureau said.

But Nicholls said the extent to which the floods and La Nina are linked to climate change isn't known because proper studies hadn't been conducted.

Yet experts have predicted that climate change would cause more droughts and floods in Australia and the country has had its share of both extremes in the past year.

''Australia has been known for more than a hundred years as a land of droughts and flooding rains but what climate change means is Australia becomes a land of more droughts and worse flooding rains,'' said David Karoly of Melbourne University's school of earth sciences, The Sydney Morning Herald reports.

Queensland Treasurer Andrew Fraser, who last week said it was a flood of "biblical proportions," told BBC Wednesday: "Words come up short now. Now it's gone beyond anyone's forecast of the size of the area affected, the number of people affected and it's not over yet."

Fraser said the state's mining and agriculture sectors would take "a long time" to get back to full production.

Noting that Queensland represents 20 percent of the national economy, Roland Randall, a senior strategist at TD Securities, the Canadian Bank, told the Financial Times that the state faces an estimated $2.5 billion loss in mining and agricultural output.