A THUNDERSTORM lashed Chinchilla, Dalby and other parts of south-east Queensland this week, but forecasters say the worst is yet to come.

Bureau of Meteorology forecaster Adam Woods said today would be the wettest day of the week with heavy rain and another thunderstorm predicted to hit the region.

"This will be falling over broad areas of the Western Downs," Mr Woods said.

"It's looking like a wet day."

He said the wet weather would be unlikely to ease off before the weekend and predicted showers and possible storms again tomorrow and Saturday.

"It's an impressive trough over the next few days," Mr Woods said.

However he said the wet weather should ease off on Sunday and into next week.

"It's certainly a wet week this week but next week shouldn't be nearly as bad," he said.

"It will move further into the south-east of the state."

Mr Woods said the rainfall was "good news for farmers" right through the Western Downs but said the rainfall was particularly good for Chinchilla.

"Chinchilla picked up 17mm from Tuesday night's rainfall," he said.

"It was very useful."

However Mr Woods urged people to make the most of their rain gauges now before the dry weather returned.

"We're seeing an El Nino spring ahead," he said.

"This means we're expecting fairly dry conditions."