A sudden change in the weather has seen Sydney cop an afternoon drenching, with reports of hail and flash flooding in some parts.

Drive listeners have reported hail battering parts of Western Sydney including Penrith, Emu Plains and the lower Blue Mountains.

Flash flooding westbound on the Anzac Bridge, Leichhardt’s Darley Road and Parramatta Road at West Street are causing delays to motorists.

The hail has forced motorists, including Drive listener Andrew, to pull over on the M1 as seen in the vision below.

A severe weather warning is in place for damaging winds, large hailstones and heavy rainfall in parts of the Blue Mountains/Hawkesbury, Gosford/Wyong and Sydney areas, issued by the Buraeu of Meteorology at 4pm.

Short-lived severe thunderstorms are continuing to develop.