Thunderstorm to hit Brisbane spectacle

Around half a million Queenslanders hope it doesn't rain on their parade.

Riverfire, the state's biggest annual celebration when thousands flock to the banks of the Brisbane River, could be hit by a thunderstorm.

Eleven tonnes of fireworks will be launched into the city skyline from barges on the water, the rooftops of buildings in the CBD and the Story Bridge to mark the end of the Brisbane Festival on Saturday night.

A series of fly-overs by RAAF jets, which start in the afternoon, will kick off the show that will light up the state's capital.

But a storm developing in the city's west in the afternoon is expected to pass over in the evening.

"It'll most likely come through the city as a line of thunderstorms, so there is a bit of a risk there'll be something around at the time of Riverfire," Gordon Banks, Bureau of Meteorology forecaster, told AAP.

"Thunder and lightning, and there's a potential for some heavy rain and some gusty winds. Hail-wise, there's a possibility but it's more likely to be further south.

"It is a bit of a concern, yes."

It would be one of southeast Queensland's first storms of the spring-summer.

Riverfire is in its 21st year.