A large rain band is leading to rainfall across much of Victoria as the Bureau of Meteorology (BOM) warns some areas could receive up to 100 millimetres overnight.
Key points:
- Holiday-goers have been evacuated from a site at a caravan park in Victoria's south-west
- Flash flooding has been recorded in the state's north
- The SES says people should remain vigilant and not drive through floodwater
The BOM has issued a severe thunderstorm warning for the Wimmera and parts of the Mallee, including Horsham, Stawell, Ouyen and Maryborough.
A severe weather warning is also in place for northern areas including Echuca, Shepparton, Wodonga, Wangaratta and Bright.
Flood watch warnings have been issued for most river catchments in the state's north and around Melbourne.
Emergency services are warning about the potential for isolated flash flooding.
Sandbagging has begun in places such as Shepparton and Wangaratta.
The rain arrived in the north-west on Sunday morning, before reaching Melbourne and central Victoria about noon.
The BOM on Saturday warned of potential flash flooding as a rain band settled over the state from Sunday afternoon and into Monday.
Storms in the south-west
At Warrnambool in the state's south-west, a large storm dumped significant rain.
According to the BOM, more than 50mm of rain was recorded in two and half hours.
Multiple properties are reported to be damaged and holiday-goers in a local caravan park have been evacuated from one site.
The State Emergency Service (SES) has responded to 46 callouts for assistance in Warrnambool in the past 12 hours.
Up to 100mm forecast
In the state's north, flash flooding was reported on Sunday afternoon in places such as Kerang and Cohuna where 18mm of rain had fallen.
BOM meteorologist Stephanie Miles said the bureau was expecting larger totals overnight into Monday.
"Anywhere between 40mm to 70mm in a six hourly total is what we're expecting," she said.
"A lot of places too could reach up to 100mm."
There are also severe thunderstorms expected, which could drop large rainfall totals and cause further flash flooding.
"I imagine that everyone is kind of on their way back from holidays today to start work … [on Monday]," Ms Miles said.
Flash flooding areas hard to predict: SES
State Emergency Service (SES) state agency commander Mark Cattell said the agency had received 140 callouts in the past 24 hours, with about 40 still unresolved.
"A lot of those are for people requesting sandbags," Mr Cattell said.
"There's also flooding threatening to enter premises and those sorts of things, which is generally … a lot of quick runoff which is threatening to get into people's homes."
He said storms were expected to build later on Sunday afternoon and flash flooding would be driven by isolated heavy falls, which were hard to predict.
The SES is also asking people to take care near floodwater.
"We're up to January 7 [and] we've had 20 flood rescues already, and that's 20 too many," Mr Cattell said.
"So we're definitely asking people not to drive through floodwater, we've seen plenty of footage of the result of doing those things."
More flash flooding in northern Victoria
Caitlin Sutterby owns the Exchange Hotel on Wellington Street at Kerang in northern Victoria.
She said her town had copped large rainfall totals this summer.
"We woke up this morning to heavy rain that we weren't expecting until later today," she said.
"We ended up having our rear beer garden under water, all of our back lane alleyway was under water.
"Pretty much everything was under water."
Fortunately, her business still has electricity and she is trying to find someone with pumps to divert water away from it.
Kerang has faced three separate flash flooding events in the space of two weeks. One of which was accompanied by a massive power outage.
Mrs Sutterby said other businesses on Wellington Street had water up to their doors on Sunday morning.
"There was just basically water everywhere, all over the street."