Severe thunderstorms are sweeping across Victoria and southern NSW on Sunday afternoon and evening, with the potential for wind gusts in excess of 120km/h.

A line of showers and storms can be seen popping up all along the cold front crossing western parts of Victoria, with more storms and cloud over the east and NSW in a pre-frontal trough. These storms will continue to build, and cross central and eastern parts of the state, including Melbourne, this afternoon and evening.

A severe thunderstorm warning was issued at 2:55pm Sunday for all western and central districts of Victoria, with warnings for damaging wind gusts exceeding 90km/h, large hail (larger than a 20c coin), and heavy rainfall that could lead to isolated flash-flooding.

Image: Severe thunderstorm warning for Victoria issued at 2:55pm Sunday. The latest warning can be found here.

These storms are moving extremely quickly, with some cells passing towns at 105km/h, and are still intensifying this afternoon. With further development and the potential for both squall lines and supercell thunderstorms, winds gusts could reach destructive speeds (exceeding 120km/h) during the late afternoon and evening. Giant hailstones (larger than a golf ball) are also a possibility if more intense thunderstorms develop.

As of 3:30pm, 3cm hail had already been observed near Bendigo.

Thunderstorms are also developing over South Australia, Tasmania, and the Australian Capital Territory on Sunday afternoon, as record warmth at the surface mixes with cold polar air aloft. Nine lightning strikes were being recorded per second over Australia at 3pm EST and will likely increase later in the afternoon.

With the storms just beginning to form and impact, please keep an eye on the latest warnings and radar at Weatherzone.com.au.