Debbie is forecast to be Category 4 when it makes landfall on Tuesday

SYDNEY — Thousands of Australians abandoned their homes as a powerful cyclone bore down on coastal towns in Queensland on Monday, while others ignored authorities’ advice to evacuate with winds forecast to reach up to 300 km/h.

Cyclone Debbie is forecast to strengthen to a Category 4 storm before it makes landfall in the northeast state early on Tuesday, the Australian Bureau of Meteorology said.

State Premier Annastacia Palaszczuk warned it would be the most powerful storm to hit the country since Cyclone Yasi in 2011, which destroyed homes, shredded crops and devastated island resorts.

About 3,500 people left low-lying townships near Townsville, while authorities advised 2,000 more people in the town of Bowen to also leave, Palaszczuk said, adding that the “window of opportunity to leave is drastically closing” as weather worsens.

“This is going to be a nasty cyclone,” Palaszczuk told Nine Network television. “These wind gusts are going to be absolutely huge.”

Second strongest

A Category 5 storm is the strongest on the five-step Saffir-Simpson scale of hurricane intensity.

The Abbot Point coal terminal and ports at Mackay and Hay Point were closed until further notice, ports spokeswoman Fiona Cunningham said.

BHP Billiton suspended operations at its South Walker Creek coal mine, which is just to the south of the cyclone’s expected path. Glencore said it was halting operations at the Collinsville and Newlands coal mines.

Gales were already lashing the tourist resorts at Airlie Beach and the Whitsunday Islands.

Townsville Airport was