A man has been plucked from floodwaters in north-west Queensland and calls for help are rising as an unseasonal deluge sets in over the state’s north.

A Queensland Fire and Emergency Services swiftwater rescue team helped the man in his 20s to safety after he got trapped in floodwaters in Soldiers Hill, a suburb of Mount Isa, about 11pm on Monday.

A severe weather warning has been issued from Townsville west to Cloncurry, and from Croydon in the north and south to Blackall.

The Bureau of Meteorology has warned flash flooding is likely with six-hour rainfall totals of 60-100 millimetres forecast from Wednesday.

Heavy rainfall is unusual outside the wet season, but some areas can expect 10 times their monthly average for May in just 24 to 48 hours.

Tweet from @BOM_Qld

The BOM said six-hour falls of up to 150 millimetres were also possible in the central-west and north-west districts.

“Locally intense rainfall with embedded thunderstorms, which may lead to dangerous and life-threatening flash flooding is also possible for the central-west and parts of the north-west districts,” the forecaster said in an alert.

QFES assistant commissioner Andrew Short said emergency services had responded to 39 calls for help in the 24 hours to Tuesday morning, but the most intense downpours were yet to come.

“We think that that’s going to go up over the coming … two to three days, we know that in fact,” he told ABC Radio on Tuesday.

“We had a single rescue out at Mount Isa, where a person found their way into floodwaters.

“That’s where we are right now. But we believe that because of the what’s playing out in front of us, then we’re going to see those numbers go up.”

He said QFES crews had pre-deployed and towns had been getting ready ahead of the rain, but hopefully it would last only three days.

Mr Short said people could still get into trouble and urged people not to drive into floodwaters.

“Think about your family, think about those around you, think about the rescuers who actually are going to have to come and help you in that event,” he said.

“We’re looking for people to be a bit considerate of others [before] getting involved in these situations.”

-AAP