WILD weather is sweeping across southern Australia with forecasters warning of a possible “significant flooding event”.

South Australia was drenched overnight, now Melbourne and Canberra are in the firing line. Victoria is bracing for a “10 out of 10” storm.

The Bureau of Meteorology (BoM) upped the possible upper amount of rain that could fall in Melbourne over the next five days from 150mm to 200mm and warned rainfall records could be broken in parts of the state.

BoM senior meteorologist Scott Williams said, “This is an event of absolute massive scale, half the inhabitants of Melbourne have never ever seen anything like this.”

At least 12 people have already been injured falling from ladders trying to clear their gutters, Ambulance Victoria has said.

Less rain than originally expected had crossed the CBD by Friday lunchtime. However, forecasters have warned that any clearing in the rain this afternoon could just be temporary with a trough bringing in more moisture and possible storms overnight and across the weekend.

The real fear is sudden and intense deluges associated with thunderstorms which could give a downpour destructive force “If you don’t get thunderstorm activity, rainfall could be in the 5-30mm range on (Friday afternoon). But if we get thunderstorm activity, we could easily see up to 50 and even 80mm quite quickly,” the BoM’s James Taylor said on Friday morning.

“The real risk in Melbourne is the next six to eight hours. A trough will move its way into Melbourne probably around 5-6pm (Friday).”

The #Rain event has started. Ararat collecting the heaviest #December rain in 7 years with 28mm in the gauge. HEAVY RAIN continuing today & tomorrow in #Victoria! @SkyWeatherAUS

— Samantha Chiari (@samanthachiari) November 30, 2017

Waiting for the ‘super storm’ to hit Melbourne #melbournestorm #Melbourne #Melbourneweather #stormageddon #rain #melbournerain

— Corey Ander (@_corey_ander) December 1, 2017

Away from the city, in the north east ranges, more constant “extreme rain” is expected. Sky New Weather meteorologist Tom Saunders said there would be no respite in the rain for northern and eastern Victoria until about lunchtime Sunday.

The Bureau has issued an unprecedented two-day severe weather warning for heavy rainfall across the entirety of Victoria, with the exception of the south west, as well as southern NSW including Albury, Wagga Wagga and parts of the ACT.

Southern NSW could get “more than a month’s rain in 36 hours” and flood warnings are also in place for Tasmania and Victoria as a low pressure trough sweeps through the country’s south.

The heavy rain is due to hit Canberra later on Friday afternoon.

The BoM is predicting showers and thunderstorms this evening with further falls expected overnight after a top of 29C.

Those in the capital can expect between 25-60mm of rain on Saturday, with the rain gauge topping out at as much as 100mm over the weekend and early next week.

Elsewhere, Hobart could get up to 80mm of rain and Brisbane 120mm.