Local man Philip Gary Lambert, 54, was coming home from work at a Gympie shopping centre when he attempted to ride over nearby Greens Creek at 1.30am on Wednesday, Acting Inspector Paul Algie said.

“As a result of riding into floodwater he has come off his motorcycle and has been washed away,” Insp Algie said on Thursday.

A motorcycle helmet and a bag in a tree were discovered during the search for Mr Lambert, and his body was found close by at 11.30am on Thursday.

“Mr. Lambert’s family were at the scene, obviously highly distressed because he lived in very close proximity,” Insp Algie said.

The motorcyclist’s death follows that of a 63-year-old woman killed in the floods triggered by a slow-moving low pressure system which has dumped up to 600mm of rain in some parts of the state’s southeast.

Her body was found in her car, which was submerged in floodwaters west of Eumundi on the Sunshine Coast on Wednesday morning.

Premier Annastacia Palaszczuk says there were 19 flood rescues and 240 calls for help throughout Wednesday and on Thursday morning.

The Bureau of Meteorology has issued a severe weather warning for intense rainfall of up to 300mm possibly causing “dangerous and life-threatening flash floods” from Maryborough to the NSW border from Thursday afternoon.

A weather system is currently sitting offshore of the Sunshine Coast, and Insp Algie said the Bureau of Meteorology is warning of two possible outcomes.

“I am very concerned that if that rain does return to the coast and it gets dumped in the Mary catchment, then we will have real problems in the Gympie area,” he said.

The forecaster is also warning of possibly damaging winds, with gusts of up to 90km/h from the Sunshine Coast to the Gold Coast.

Palaszczuk urged residents in the state’s southeast to watch out for alerts and avoid going out if possible.

“Our message is very clear to people this afternoon: please listen to your radio, social media, television,” Palaszczuk told parliament on Thursday.

“Please keep up to date to see what is happening, especially if you’re planning to go out this evening and probably during the pick up time this afternoon for (school) children.”

There is a major flood warning for Eyre Creek and moderate flood warnings for the Georgina, Mary and Stanley rivers, as well as Tinana and Six Mile creeks.

Boaties were also urged to rethink planned outings.

Transport and Main Roads Minister Mark Bailey said a trough and low pressure system threatened to bring heavy to intense rainfall and strong winds along the coast.

“Boaties can expect poor visibility, stronger stream flows and currents and possible flash flooding with the associated dangers of floating or submerged debris,” Mr Bailey said.

“Conditions this week and through the early part of the weekend make it dangerous for anyone thinking of going boating.

“I urge skippers to rethink any plans to take their boats out.”