The entire state of Victoria and large parts of New South Wales and South Australia are on flood watch as an unprecedented wet weather system looks to smash through the recent record-breaking heat.
Southern and eastern Australia is about to cop a lashing from Mother Nature, the Bureau of Meteorology (BoM) advises, with falls of up to 200mm predicted in parts of Victoria and western NSW.
Severe thunderstorms are expected in South Australia late on Thursday and into Friday, bringing with them damaging winds, hail and heavy rainfall up to 100mm.
As the system moves into Victoria and NSW, that predicted rainfall only gets higher.
"The system will ramp up over Victoria and western NSW on Friday and into Saturday with rainfalls of 100-200mm expected in these areas, particularly those areas closer to the ranges,” BoM senior forecaster Scott Williams said.
“Peak falls in the northeast of Victoria could top 300mm over the 48 hours to Saturday night.
"Melbourne is likely to see at least 50 to 100mm of rainfall and severe thunderstorms overnight Friday into Saturday. There is a chance that heavy rain could return to the Melbourne area on Sunday, possibly delivering another 50mm or more.”
The entire state of Victoria is the subject of an initial flood warning, while much of southern NSW is also on flood watch.
"Southern parts of NSW and the ACT could see falls in excess of 100mm on Friday and Saturday with some places seeing 200mm,” Mr Williams said.
The weather could hit Canberra but at this stage is unlikely to impact Sydney.
"Rainfall rates could be quite intense," said James Taylor, a senior meteorologist with the BoM's extreme weather desk. "There's some risk of riverine flooding."
"To get a rainfall event like this at any time of the year of the year is certainly unusual," Mr Taylor said, adding that spring is the most likely season for such weather.
In Wagga, where it’s expected to receive 50mm on Friday and 80mm on Saturday, the State Emergency Service (SES) called for extra volunteers to help fill sandbags on Wednesday night after a flood watch was issued for the Murrumbidgee River.
Acting SES regional controller for Murrumbidgee Jon Gregory said the alert could be best described as a “heads-up”.
“It’s not a bulletin or warning. It’s advice that there could be minor to moderate flooding, depending on rainfall,” Mr Gregory said.
With Victoria under a severe weather warning, the SES isn’t taking chances.
Bendigo SES deputy controller Natalie Stanway said residents should prepare their properties before the rain hits.
“If that volume of rain comes down with blocked gutters, water can come into ceilings, so it is well worth (clearing gutters) and checking down pipes before the rain starts,” she said.
“If like last Sunday, we received something like 37 calls in a short space of time, it is not possible for us to get to everybody.
“So people need to prepare to take steps themselves.”
WATCH: BoM senior meteorologist Adam Morgan explains how the wild weather will come in.
The State Emergency Service advises that people should:
- Not walk, ride or drive through flood water
- Keep clear of creeks and storm drains
- Be aware that in fire affected areas, rainfall run-off into waterways may contain debris such as ash, soil, trees and rocks
- Be alert that in areas recently affected by fires, heavy rainfall increases the potential for landslides and debris across roads