SEVERE thunderstorms which may cause flash flooding are moving across parts of Victoria this afternoon.

A warning for damaging wind, heavy rain and large hailstones has been issued for Central, North Central, parts of the Northern Country, North East and West and South Gippsland.

Bureau of Meteorology duty forecaster Tracey Malmborg told Weekly Times Now the thunderstorms extended from Seymour, into Melbourne and across to Wilson's Prom in the west.

She said a second trough of cold air would bring further storms tomorrow in the southern half of Victoria.

Ms Malmborg said Cape Otway had 12mm of rain since 9am to about 2pm and Mt Macedon had 10mm.

The warning from the bureau states the rain may lead to flash flooding. Places listed in the warning include Seymour, Geelong, Melbourne, Morwell, Traralgon and Moe.

The next warning is due at 5.10pm.