Thunderstorms are forecast to sweep through Sydney over the next few days, continuing the wet weather that began on the weekend.

A severe thunderstorm warning was issued by the Bureau of Meteorology on Tuesday afternoon for parts of the metro region, with large hailstones, heavy rainfall and damaging winds expected in the Illawarra and Blue Mountains over the next several hours.

Fog over Sydney’s northern beaches on Tuesday morning, ahead of a warm day that will result in afternoon storms. Credit:Nick Moir

Bureau of Meteorology duty forecaster Gabrielle Woodhouse said about 7pm that severe thunderstorms would make their way across Sydney's far western suburbs in the next hour.

"We are experiencing bursts of rainfall which is expected to move from the western suburbs into the Sydney basin but won't be as intense towards the coast," she said. "Along with strong winds, hail is also not out of the question."