After a dark and rainy Friday, Melbourne's skies have begun to clear, with light showers and a slight chance of a thunderstorm forecast for this evening.

"There's still some showers around. We've just had one go through the city a couple of moments ago," said Bureau of Meteorology senior forecaster Rod Dickson around 5pm.

"There's probably not as much thunderstorm activity around as initially anticipated."

However Mr Dickson said severe thunderstorms were expected over the Mallee in the next few hours, and areas northwest of Ballarat were also due to receive heavy rainfall.