South Australia weather: Month’s worth of rain falls in one day

A huge rain band has swept parts of Australia, including one town that was soaked by its heaviest December rainfall in 75 years.

A huge rain band has swept parts of SA, delivering record-breaking falls to cities and towns including the capital.

An unseasonal cool change and dramatic wet weather event brought heavy rain, severe thunderstorms and damaging winds to SA this weekend.

More than 20,000 lightning bolts hit the state while wind gusts of more than 100km/h raged.

A storm rolls in over SA. Picture: Adelaide Advertiser.

The event made for the wettest December day in 75 years in Cleve, on SA’s Central Eyre Peninsula, with 55mm falling in the 24 hours to 9am on Sunday. It caused the nearby Yeldulknie Weir to overflow for the first time in nearly 30 years.

Kimba received 47mm, its heaviest December rainfall in 61 years, while Mount Ive saw 51.2mm, breaking a 53-year-old December rainfall record.

Minlaton, Noarlunga and Edithburg received 47.8mm, 40mm and 36.8mm respectively, all of which broke December rainfall records that were more than 20 years old. For Wudinna in western SA, the event set a historic record of 48.6mm received in one day — the largest single-day deluge since that meter opened in 1999.

Rainfall in the 24 hours to 4:30pm local time on Sunday. Picture: Weatherzone.

While the totals mightn’t sound like much in other parts of the country, they’re notable because SA is usually dry at this time of year.

“By the end of [Sunday], it’s anticipated that some of these places will have received more than 100mm of rainfall, and while that’s not a lot for some parts of Australia, it’s typically dry in SA,” Bureau of Meteorology meteorologist Angus Hines said.

“A lot of places [that are] expected to receive between 50 and 100mm of rain only average about 20mm over the course of a typical December, so that’s double or triple what they normally get.”

Adelaide, for instance, received double its average monthly rainfall for December in a single day. More than 50mm of rain fell on the city on Saturday, trampling its December average of 25.9mm, according to the BOM.

Rainfall over SA on Monday. Red shading indicates heavy rains. Picture: BOM.

The region was also battered by strong winds.

Cape Borda recorded severe gusts of up to 104km/h on Monday morning, while Stenhouse Bay recorded 87 km/h and Cape Willoughby, 81 km/h.

South-easterly winds are “notoriously damaging” for parts of the Mount Lofty Ranges and Adelaide Hills, according to Weatherzone.

“When a low-level inversion forms, such as during a cold day and night like Sunday, south-easterly winds get squeezed between the ground and the inversion like a wind tunnel, amplifying the winds over the region,” Weatherzone meteorologists explained.

More than 900 calls were made to State Emergency Services in SA over the weekend as the wild weather destabilised trees and powerlines.

In Marryatville in Adelaide’s east, a 50 tonne gum tree flattened a family home. Local resident Glynn was inside the home at the time but escaped uninjured.

“I mean it’s pretty devastating, first we’re pretty glad that Dad is OK,” Glynn’s daughter, Hannah, told Channel 9.

More than 30,000 properties lost power while some schools were shuttered on Monday.

Wind gusts expected in the early hours of Monday morning. Red and purple indicate strong winds. Picture: Weatherzone.

The rain also drove bushfire warnings, with an extreme fire danger warning in place for the Murraylands district on Monday.

“Hot and unstable conditions with fresh and gusty southeast to north-easterly winds shifting west to north-westerly with the passage of a trough,” the BOM explained.

“Thunderstorms are expected with strong and erratic outflow winds and the risk of damaging wind gusts and heavy falls.”

A severe thunderstorm warning remains in place for southeast SA, with the rain band and low pressure system expected to linger for several more days.

Flash flooding is possible in locations including Lameroo, Meningie, Karoonda, Berri, Tailem Bend and Coonalpyn, the BOM said.

Originally published as South Australia weather: Month’s worth of rain falls in one day