‘Unstable’ weather system to smash FOUR states with severe rain, hail, winds

An “unstable” weather system will smash several states from Thursday with meteorologists warning it will go down as “one of the most significant storm days we've had this season".

Moist winds blowing off the Pacific Ocean and into a low pressure trough, combined with cold air in the upper atmosphere, are set to produce severe storms over the next week.

Forecasters are predicting flash flooding, heavy rain, damaging winds and large hail with parts of Queensland, New South Wales, Victoria and South Australia in the eye of the storm.

“Today is probably the biggest day but the next couple of days also look reasonably significant,” Brett Dutschke, Meteorologist at the Weatherzone, told Yahoo News Australia.

“Any of the next three or four days in isolation could be significant days.”

He said the system’s slow movement, as well as “extraordinarily” humid air as a result of La Nina, have made the situation worse.

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“It’s just given more time for these humid easterly winds to fuel a low pressure trough as it slowly moves from west to east,” Mr Dutschke said.

“Because it is slow moving, some locations are picking up rain and thunderstorms for three or four days running.”

Queensland’s ‘big rain’ event

The Sunshine state is set to cop the worst of the weather with residents from the Northern Goldfields to the Darling Downs put on alert.

The Bureau of Meteorology has issued a severe thunderstorm warning for eastern islands and the coast from Bowen to Shoalwater Bay, with damaging winds, large hail and heavy rain possible.

It’s already been a very wet week for Queensland with some areas breaking rainfall records.

More than 120 millimetres has fallen in Lochington and Springsure in the Central Highlands over the last couple of days, the biggest total in six years.

While Heathwod, outside Brisbane, recorded 150 millimetres in the past two days, it’s highest falls in about 12 years.

“For some places it is not just big rain for October,” Mr Dutschke said. “It's big rain outright.”

Significant damage expected in NSW

Northwestern and central western NSW are the main areas of concern for severe thunderstorms, according to Weatherzone.

“[It’s] the most likely area for significant damage from thunderstorms,” Mr Dutschke explained.

Large hail, heavy rainfall and damaging winds are expected, as well as flash flooding.

In the last 24 hours, Mungindi in northern NSW gained 58 millimetres of rain to notch up its biggest October rainfall in 53 years.

While Wilcannia broke a 12-year daily rainfall record for the month with 40 millimetres.

Widespread storms for Victoria

After a few dry days following record flooding, the wet weather will pick up again in Victoria’s north from Thursday, with storms becoming fairly widespread over the next week.

“Just about everywhere in the state will receive some rain or a thunderstorm over the next few days,” Mr Dutschke said.

“Some places will get rain and storms for four days or more. It's a big deal."

With the month still far from over, many parts of northern Victoria and north central districts, where a lot of the main flooding has been occurring, have already tripled their average rainfall for October.

South Australia ‘not going to be left alone’

While South Australia will escape the worst of the weather, some parts of the state will still experience intense rain and thunderstorms.

“There'll be some showers and thunderstorms most days in the next week, particularly in the east and occasionally reaching central and western parts of the state,” Mr Dutschke said.

“So they're not going to be left alone that’s for sure but in general, it won't be quite as intense as what is going to be going on further east.”

He added that any flooding would be brief and “relatively minor.”

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