The Bureau of Meteorology has issued a severe weather warning for a huge chunk of NSW and storms continue to batter Australia's east coast.

The BOM revealed early Thursday morning that heavy rainfall was on the cards for people in parts of North West Slopes and Plains and Northern Tablelands Forecast Districts, which may lead to flash flooding.

"Humid air persists over New South Wales, and is interacting with a surface trough over the interior to produce showers and storms over the northwest slopes, and some locally heavy falls," the BOM said.

"Heavy rain which may lead to flash flooding is possible this morning, with the focus initially in the western part of the warning area, then shifting eastwards.

"In these areas, widespread falls of 20 to 40mm are likely, mostly falling before midday, with local totals possibly exceeding 100mm beyond those experienced earlier this morning."

Locations which may be affected include Inverell, Moree, Barraba, Ashford, Bellata and Bingara.

It revealed Upper Horton has received 165mm of rain between midnight and 6am, with Cobbadah recording 95mm.

Rainfall and storms are also expected for the Sydney area, with storm activity tipped to ramp up in the days ahead.

The warning comes after a man was killed after being swept away by flash flooding in Killarney, Queensland yesterday evening.

Investigations indicate the 69-year-old farmer was moving cattle to higher ground at a property along Condamine River Road when he and his vehicle were consumed by rapidly rising water and washed away around 8.30pm.

Emergency services were called to the scene and immediately commenced a search and rescue operation.

The man was located deceased inside his vehicle approximately 100m downstream at 12.20pm.

A report will be prepared for the Coroner.

Meanwhile, new footage has shown the impact of the storms that have lashed Australia's east coast for days on end, with a time-lapse video revealing the moment rapid flooding inundated a bridge.

The clip was created with Bellingen Shire Council's webcam, which recorded Moodys Bridge at the Kalang River for hours this week.

It shows the bridge, located south of Bellingen on the NSW Mid North Coast, rapidly overcome by rising floodwaters which cut off residents on either side.

The waters soon completely swallow the road and bridge, with railings and nearby land totally underwater.

The footage is used by the council to warn locals about the real-time dangers of certain areas during bad weather events, with Bellingen Shire Council mayor Dominic King telling it was "quite amazing how quickly the water goes up" in the area.

Meanwhile, more heavy rain is on the way for the area, with the Bureau of Meteorology issuing a strong wind warning for the Coffs Coast, Macquarie Coast and Hunter Coast and a severe thunderstorm warning for "heavy rainfall" in the North West Slopes and Plains and parts of Mid North Coast, Hunter, Central Tablelands and Northern Tablelands.

Moodys Bridge started out reasonably dry … Picture: Bellingen Shire Council
Moodys Bridge started out reasonably dry … Picture: Bellingen Shire Council

According to the BOM, "severe thunderstorms are likely to produce intense rainfall that may lead to dangerous and life-threatening flash flooding in the warning area over the next several hours".

Locations which may be affected include Scone, Armidale, Tamworth, Gunnedah, Moree and Narrabri.

However, there is some good news, with a severe thunderstorm warning cancelled for the Metropolitan, Illawarra, south coast, Southern Tablelands, Central West Slopes and Plains, South West Slopes, Riverina, Snowy Mountains and Australian Capital Territory districts as conditions improve.

… But it didn’t take long before it was swallowed. Picture: Bellingen Shire Council
… But it didn’t take long before it was swallowed. Picture: Bellingen Shire Council

The State Emergency Service (SES) advises that people in affected areas should keep clear of creeks and storm drains, avoid walking, riding bikes or driving through flood water and seek refuge in the highest available place if you are trapped by flash flooding, and ring triple-0 if you need rescue.

According to the SES, residents should also be aware that run-off from rainfall in fire affected areas may behave differently and be more rapid. It may also contain debris such as ash, soil, trees and rocks.

It advises people to unplug computers and appliances, avoid using the phone during the storm, stay indoors away from windows, and keep children and pets indoors as well.

Originally published as 'Severe weather warning': Millions at risk

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