Flooding could last ‘weeks or months’ warns BOM

Flooding from the mega rain could last for “weeks, or months” meteorologists have warned due to the sheer amount of moisture coming down.

Meteorologists have said it could take weeks, or months” before much of the flooding caused by this week’s huge rain event finally subsides.

Record amounts of rain have fallen on the east coast over the last week. Mt Seaview, 80kms west of Port Macquarie, has seen the heaviest rain nationwide recording 1083mm by Tuesday afternoon, more than a metre. In some areas, two thirds of the annual rainfall has descended in a matter of days.

A second major front charged in from the west today forming a single mega rain event stretching from south east Queensland to Tasmania.

Bureau of Meteorology (BOM) forecaster Jonathan How said today would be a “critical day”.

Impacted will include parts of Queensland, NSW, the ACT and even eastern Victoria.

“We’re really concerned about the rainfall from early Tuesday morning into southern

It may have been going for days but unfortunately this situation is far from over. This map shows #Flood Watch & #Warning zones with rain radars overlaid. You can see rain still falling in flood areas, with more forecast for coming days https://t.co/n6uSzt271E@[e-mail]/oXD9pWq4UI

— Bureau of Meteorology, New South Wales (@BOM_NSW) March 22, 2021

Queensland and Brisbane right down the NSW coast and the ACT and central tablelands into Gippsland,” Mr How said.

“There are concerns for heavy rain and the heaviest storms, which could bring thunderstorms.”

Major flooding is expected in Grafton overnight, as well as flooding on the south coast. That’s in addition to already flooded areas.

It comes a day after Queenslanders experienced torrential rain and flash flooding and entire towns in NSW were forced to evacuate as rivers and creeks swelled then overflowed.

Sky News Weather senior metrologist Tom Saunders said this morning that there was “24 hours of wild conditions left”.

RELATED: Follow the latest flood updates as they happen

Two rain bands are set to merge across the east coast. Picture: Sky News Weather.

FLOODS COULD LAST ‘WEEKS, MONTHS’

The skies are set to clear late on Tuesday and into Wednesday. Nonetheless, the effects of the weather could last for months, said the BOM’s Victoria Dodds this afternoon.

“Coastal catchments tend to respond very quickly. So, as that rain clears the situation can improve.”

That doesn’t mean the floodwaters will recede immediately. In western Sydney, the mid north coast and the south coast of NSW as well as Queensland, rivers could remain high until the weekend as that rainfall washes out to sea.

But as we head into the weekend, with little extra rain, rivers should begin to return to normal levels.

However that is certainly not the case west of the Dividing Range.

“In western New South Wales, once the rivers get going, they can keep flowing for not just days but weeks or months on end, as the floodwaters make their way through the state,” said Ms Dodds.

The issue is manifold. In the interior, the land is relatively flat, so the water is given little encouragement to drain. And the distance that water has to cover is vast before it finds its way to a major river like the Murray or to Lake Eyre.

TUESDAY’S WARNINGS

In NSW, residents along the Colo River have been told to “prepare to evacuate” by helicopter and boat as “extremely high” record floods threatened the Hawkesbury-Nepean catchment.

In western Sydney, thousands more residents are preparing to evacuate as the Hawkesbury River continues to rise.

And on the mid-north coast, residents of Kempsey spent a second night away from home as the Macleay River threatened to surge again.

In Queensland, beaches are shut, theme parks closed down and the capital drenched with more than 100mm in 24 hours.

All of the Gold Coast’s theme parks were shut on Monday due to flash flooding and dangerous surf conditions shut the region’s beaches.

Further inland from the Gold Coast, Mount Tamborine recorded more than 250mm and footage on social media showed a tiny creek transformed into a torrent of water.

Significant rain expected in the southern interior from today as a trough moves into SW #WesternQld. Heavy rain possible across the south as this new system moves E. The current #SEQ coastal trough will make way for the western rain tomorrow. Forecasts: https://t.co/d8hW8TyyRwpic.twitter.com/ixOrd8V4kZ

— Bureau of Meteorology, Queensland (@BOM_Qld) March 22, 2021

Queensland SES director Brian Cox said Brisbane and the Gold Coast had been the worst hit.

“The emergency warning went out last night to most of the residents in the Gold Coast area; we received over 300 calls for assistance since,” he said.

“There’s also been swift water rescues conducted. We’re also warning our residents that the rain has not stopped, we still have another couple of days to go through.

“What we are prepared for is more rain on its way … there’s quite a few smaller rivers, as well as water across roads. If it’s flooded, forget it.”

Despite Queensland expecting 200mm in some parts of the state over the coming days, Mr Cox said NSW was still worse off.

“I don’t think (we’ll get) as much as NSW,” he said.

“In actual fact, to support this at once we sent a team of 60 down to NSW yesterday.

“We’ve also got another 40-person team ready to deploy to NSW to help them out.

“What we are concerned about here in Queensland is that flash flooding. That’s the highest risk we have.

“The water is saturated from the ground. And we know that there is a significant risk that this very short notice rainfall is ahead of us.”

– with Natalie Wolfe

Originally published as Flooding could last ‘weeks or months’ warns BOM