It may not be a “rain bomb” but record rainfall is bringing warnings of flash flooding and severe thunderstorms as wild weather lashing almost every state and territory moves east.
The buzz term hitting the headlines has been used to describe Australia’s drenching this week, with flood and marine warnings in place across the nation.
“It’s a good metaphor for what we’re expecting but it’s not a technical term we use,” said a Bureau of Meteorology forecaster, Jonathan How.
“For some places it will feel like an explosion of rain, but anyone in meteorology would never say that, we try to steer clear from dramatic terms people like to coin.
“You could say a storm or rain outbreak, which is a bit more subdued.”
The low pressure system brought record spring rainfall in the Northern Territory overnight, with more than 100mm recorded in Alice Springs, the heaviest rainfall in 20 years.
“It broke the record for the wettest November ever,” How said. “There are still quite a few flood watches for large parts of central and southern Northern Territory, as well as northern South Australia and southern Queensland.”
Widespread record rainfall will pass over south-west Queensland in the next two days, with between two to three times the average November rainfall expected.
Four catchments in New South Wales are under flood watch, with major flooding expected in rivers up to the Queensland border and flash flooding expected in inland areas. Six hourly rainfall totals exceeding 100mm are possible for northern inland parts of the state.
Two-thirds of dams in NSW are already above 90% capacity, while Menindee Lakes is at 112% and Brogo Dam is sitting above 102%. The Lachlan River is expected to remain above 2.7 metres until early next week.
“We’ve just issued severe weather warnings for heavy rain in inland New South Wales and southern Queensland, with possible flash flooding particularly in Tamworth and parts of Darling,” How said.
Sydney will see a chance of thunderstorms on Thursday and Friday, with winds of 15km/h to 20km/h and a 90% chance of rain until showers ease off on Saturday.
Melbourne will see its highest chance of rainfall on Friday and Saturday, with winds of up to 40km/h on Sunday and possible hail.
High rainfall will also lash the Australian Capital Territory, Queensland and South Australia, with thunderstorms expected after pockets of heavy rainfall overnight in north Adelaide, Western Australia and the Queensland coast.
North Rockhampton recorded 341mm of rain up to 9am Wednesday, while Bundaberg south saw falls of 68mm.
“As the storm moves east it’s given us a taste of what’s to come,” How said. “Major flooding can be a risk to communities along rivers, but flash flooding will also cause headache and grief to farmers harvesting, likely to lose their crops. The flooding impacts will last well into next week.”
The ACT is expected to be the wettest capital come Friday, once a low pressure moves to the territory, with falls expected between 25mm and 50 mm.
“It could go higher,” How said. “They’re really going to cop it.”
Storms are also expected in Brisbane and Sydney before easing off late Friday afternoon or early evening. But Victoria will see “dangerous easterly winds” increase on Friday which could cause tree damage across southern parts of the state, until an eventual easing early next week.
As storms continue, summer is looking “quite far off” with tropical moisture brewing across the east coast and cold air pushing from the south bringing a wet, cold and windy end to spring.
“It’s going to be cold across the country, more like wintertime,” How said. “We’re seeing maximum temperatures five to 15 degrees below average, and temperatures of 12 and 13 degrees in Canberra ... it’s very unusual for November.”