Large hail and severe thunderstorm warning for flood-stricken towns

Severe thunderstorms and dangerous flash-flooding are forecast to hit inland areas of south-east and central NSW as a low-pressure system bringing heavy rain, damaging winds and large hail sweeps across the state on Sunday and Monday.

Emergency Services Minister Steph Cooke said on Sunday morning that harsh weather conditions were expected in parts of the South Western Slopes, Southern Tablelands, Riverina, and the ACT in the next 24 to 36 hours.

By 7pm on Sunday, severe thunderstorms had passed in Riverina and the ACT, but affected areas were expanded to include the Central Tablelands, Central West Slopes and Snowy Mountains. Heavy rain was expected to develop across the area from Sunday afternoon, which could lead to flash flooding.

While rain is expected to ease on Monday morning, the Bureau of Meteorology has warned of dangers in areas including Mudgee, Yass, Wellington, Wagga Wagga, Albury, Young, Tumbarumba and Holbrook. By 7pm, the list included coastal areas south of Sydney and the Illawarra such as Wollongong, Nowra, Orange, Dubbo, Cobar and Bourke.

“These thunderstorms may also lead to locally intense rainfall which may lead to dangerous and life-threatening flash flooding,” the bureau said.

A “severe thunderstorm warning” would be issued if these conditions develop, the bureau said.

The NSW State Emergency Service said crews had carried out five flood rescues and fielded 145 requests for assistance in flood-affected areas of NSW in the 24 hours to Saturday afternoon.

Cooke said emergency services authorities had established an incident control centre at Goulburn and deployed flood rescue teams to high-risk locations across the state.

“Our catchments and landscape are very saturated, they have been all year. Any additional rain that falls on our soils has nowhere to go, and therefore it does increase the risk of life-threatening flash flooding and of riverine flooding in the days ahead as our river systems try to absorb even more of the rain that continues to fall.”

The Bureau of Meteorology’s Steve Bernasconi said a low-pressure system drawing warm, moist air from tropical areas into NSW had brought wide bands of rain and severe thunderstorms throughout much of the state.

Bernasconi said warm, humid conditions in NSW on Saturday had created “unstable” weather conditions, with intense bursts of rain in Wagga Wagga and Grafton.

He expected these conditions to worsen across inland areas on Sunday, with a “very high chance” of severe thunderstorms bringing more intense rainfall of 30 to 40 millimetres, damaging winds and possibly hail.

“The trough and the cold front will combine and start marching across the state throughout the day and into Monday. That will extend to the coastline, and potentially the Sydney metropolitan area.

“All of this adds to the existing, extended flooding that’s happening in inland NSW.”

About 4pm, the Bureau of Meteorology updated the state’s severe thunderstorm warning to include the threat of large hail in areas including Orange, Canberra, Goulburn, Dubbo, Cobar and Bourke.

Large hail is two centimetres in diameter or larger.

The bureau advised people in affected areas to move their car under cover and away from trees, unplug computers and appliances and stay indoors away from windows.

Renewed warnings were issued for the state’s Central West towns of Nanami and Forbes as a result of forecast moderate to heavy rainfall over the Lachlan River.

There is a possibility of major flooding at Nanami from Monday and at Forbes Iron Bridge from Tuesday, with further rises possible. Moderate flooding is possible from Monday at Cowra.

Bernasconi said a “spell of cooler, drier and more settled conditions” was expected from Tuesday to Friday.

NSW State Emergency Services Minister Commissioner Carlene York urged residents to make safe decisions, such as avoiding driving through floodwaters and securing loose items on their properties, in the next day or two.

“Some of our towns have been in major flooding for some months, and we want to make sure that everyone remains safe through this next weather event that’s coming,” York said.

Cooke said emergency services crews were continuing their operations to deliver supplies including food, medicines and animal fodder to communities in flood-hit areas covering more than 40,000 square kilometres of NSW.

“To put it into context, that is the size of Switzerland,” Cooke said.

Our Breaking News Alert will notify you of significant breaking news when it happens. Get it here.