Severe thunderstorms and heavy rain is lashing large areas of Victoria, as authorities urge residents to brace for dangerous flash flooding.

Communities across northern and central parts of Victoria, including Melbourne, were forecast to be impacted by wild weather from Tuesday afternoon.

The Bureau of Meteorology warned of “very dangerous thunderstorms” by 3pm in Melbourne likely to cause heavy rainfall and flash flooding.

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The weather is moving towards the southeast and is forecast to affect Glen Waverley, Ringwood, Lilydale, Dandenong, Belgrave and Berwick by the late afternoon.

Rainfall of 40 to 70mm is expected across the state.

SES personnel work to block a flooded underpass in South Melbourne. Credit: AAP

Residents should remain on alert to flash flooding in the coming hours, Victoria State Emergency Service spokesperson Josh Gamble told AAP.

“Flash flooding happens fast. Roads can become very dangerous very quickly. It’s deeper than it looks,” he said.

“Low-lying and creekside communities (should be) on alert, particularly those that are known in those flash flood areas in and around the Melbourne areas.”

The SES has urged motorists to avoid travel if possible, but to avoid floodwater, mud and debris if needing to commute.

Residents should check loose items including umbrellas and trampolines are secured and move vehicles away from trees.

- With AAP