Wettest day on record for parts of SA
In short
The winter storm that loomed over the weekend has delivered, dumping record-breaking rain across parts of South Australia and Victoria.
Two South Australian towns recorded their wettest day on record, and flash flooding, water rescues and damaging alpine winds have followed.
What to watch
The rivers are the story now, so treat swollen waterways, muddy flood plumes and dangerous coastal bars as the real hazard this week.
The powerful cold front that prompted a flood watch across the south has now done its damage, and the numbers are genuinely striking.
Widespread heavy rain fell across South Australia and Victoria over the weekend, with two towns setting all-time daily rainfall records in the process.
The Bureau of Meteorology reported the heaviest falls through the ranges, where saturated ground has sent creeks and rivers rising quickly.
For anyone who fishes, boats or paddles the rivers and estuaries of the southeast, the coming days are about the aftermath, not the storm itself.
Wettest day on record
The standout figures came from South Australia's west coast, where the rain fell hardest against the usual dry winter pattern.
Ceduna recorded 75 millimetres and Wudinna 69 millimetres, and both towns notched their wettest day on record in doing so.
On the western Eyre Peninsula, where a whole winter month can pass with little rain, a single day like that is extraordinary.
Records like these are the clearest sign that this was not a routine front but a genuinely notable weather event.
The big totals
Through the ranges the totals climbed even higher, driven by moist air forced up and over the terrain.
Mount Buffalo Chalet in Victoria collected 161 millimetres from 9am Sunday, while Strathbogie North gathered 128 millimetres over the same period.
The Flinders Ranges and Victoria's eastern ranges both topped 150 millimetres, and a number of spots in the Adelaide Hills passed 100 millimetres.
Falls of that size on cold, sodden winter soil run straight off the slopes and into the rivers below.
"A whole month of winter rain in a day is the kind of total that reshapes rivers, not just wets the ground."
Flooding and rescues
The flooding that the Bureau's watch had warned about duly arrived, catching some people out on flooded roads.
Emergency services rescued three people in South Australia after they drove into floodwaters, a reminder of how quickly a road can become a trap.
Both flash flooding and slower riverine flooding remain a risk, because the rivers are still carrying the weekend's rain downstream.
The simple rule holds firm, so if you meet water over a road, turn around rather than trying to guess its depth.
Damaging winds behind the front
The same system brought a serious wind threat, with severe weather warnings for damaging gusts across the eastern ranges and the alps.
Over the Snowy Mountains above 1500 metres, winds averaged 60 to 70 kilometres an hour with peak gusts above 90.
Higher still, above 1900 metres, gusts topped 125 kilometres an hour, which is destructive wind in anyone's language.
The front was pushing across New South Wales and offshore by Monday evening, so the wind eases from the west first.
What record rain does to the coast
The effects of a downpour like this do not stop at the riverbank, because all that water eventually reaches the sea.
Rivers in flood carry a brown, sediment-laden plume of freshwater out into the estuaries and along the coast for days.
That plume drops the water clarity and the salinity, and it can push fish out of their usual haunts while they wait for conditions to settle.
It also carries logs and debris downstream, turning a familiar estuary into an obstacle course almost overnight.
On the water right now
For boaters the message is blunt, because swollen rivers and floating debris make the next few days a poor time to be out.
Coastal bar crossings are especially dangerous when heavy river outflow meets an incoming swell, so treat every bar with real caution.
Anglers can still do well once the water clears, and the edge of a receding flood plume often concentrates baitfish and predators.
For now, though, the safest move is to let the rivers drop and the debris flush through before you launch.
How long will it last
The front clears offshore quickly, but its legacy lingers in the rivers, which tend to peak a day or two after the rain stops.
Alpine winds ease through Monday, and the showery airstream behind the front gradually fades across the southeast into midweek.
The muddy plumes along the coast take longer to clear, so expect discoloured water in the estuaries for several days yet.
Keep an eye on the Bureau's warnings, because river levels can rise again if further rain lands on already full catchments.
Common questions
Where did the record rain fall?
Ceduna and Wudinna on South Australia's west coast both recorded their wettest day on record, with 75 and 69 millimetres respectively.
How much rain fell in the ranges?
Mount Buffalo Chalet gathered 161 millimetres from Sunday morning, and both the Flinders and eastern Victorian ranges topped 150 millimetres.
Is it safe to drive or boat through floodwater?
No, as floodwater hides its depth and current, and three people already had to be rescued after driving into it in South Australia.
When will the coast clear up?
The muddy flood plumes can linger for several days, so give the estuaries time to settle before you expect clean water.
Check the latest South Australian warnings and Victorian warnings before you head anywhere near the water.
