A strong tropical cyclone roaring toward Australia's flood-ravaged northeast will likely cause powerful and deadly flash-flooding, officials warned Tuesday, as residents braced for what's predicted to be one of the fiercest storms the region has ever seen.

Cyclone Yasi was barreling toward the Queensland state coast as a strong Category 3 storm on Tuesday with winds up to 137 mph (220 kph). It was expected to hit the coast Wednesday as a violent Category 4 storm with wind gusts up to 155 mph (250 kph), dumping up to three feet (one meter) of rain on communities already saturated from months of flooding.

"This storm is huge and it is life-threatening," Queensland Premier Anna Bligh said. "I know many of us will feel that Queensland has already borne about as much as we can bear when it comes to disasters and storms, but more is being asked of us — and I am confident that we are able to rise to this next challenge."

Yasi would be the second storm to batter Queensland in a week. Cyclone Anthony weakened quickly after hitting land Monday morning, and damage was limited to uprooted trees and downed power lines.

Queensland has already suffered flooding since heavy rains started in November. The floodwaters killed 35 people, damaged or destroyed 30,000 homes and businesses and left Brisbane, Australia's third-largest city, under water for days.

Yasi is expected to strike farther north and spare Brisbane and towns that have suffered the worst of the recent flooding. Still, Bligh said the storm's path could change and residents up and down the coast needed to be prepared.

"We could see very powerful flash flooding that will be dangerous and potentially deadly," said Bligh, who described the storm as one of the largest and most significant cyclones the state has ever seen.

Hamilton Island, a popular tourist destination off Queensland, began evacuating some visitors on Monday, and other islands were considering doing the same, Bligh said. Some nursing homes along the coast were evacuating, and residents of low-lying areas were urged to consider leaving their homes until the storm has passed.

"We're telling anyone in the low-lying areas they need to be moving today and find another place to go to," said Val Schier, mayor of the northern Queensland city of Cairns.

Deputy Police Commissioner Ian Stewart said residents should be prepared with flashlights, food and water.

"Please make no mistake: this storm is a deadly event," Stewart said. "Now is the time to act. Prepare yourself. Relocate out of the high-risk zones."