Thunderstorms and lightning across New South Wales could exacerbate dangerous fire conditions, after much of the east coast sweltered through what was forecast to be the final day of high temperatures this year.
A cool change was due after some regions sweated through heatwave conditions, with temperatures pushing into the mid-40s.
It prompted a severe thunderstorm warning for northwest NSW, with possible damaging winds, large hailstones, heavy rainfall and flash flooding.
The Bureau of Meteorology warned Gunnedah, Narrabri, Wee Waa, Baradine, Mullaley, and Boggabri to be on high alert late on Friday. However it warned the forecast storms could spark more fires across the state.
Lightning had already sparked fires throughout NSW, with almost 70 blazes reported by late Friday. The NSW Rural Fire Service said none were of significant concern late on Friday, but warned there were total fire bans in place in the Northern Slopes, North Western, greater Hunter and greater Sydney regions.
Northern Slopes was the only NSW area with a total fire ban in place for Saturday, it said.
Stephen Stefanac from the Bureau of Meteorology said the thunderstorms posed a double danger: “Thunderstorms are accompanied with lightning, and lightning can ignite new fires in the landscape when the thunderstorms are accompanied with little rainfall.
“Many thunderstorms in NSW today will contain little rainfall so there’s a risk of new ignitions.
“Thunderstorms today have the capacity to produce strong to possibly damaging wind gusts, and this poses danger to people or crew on the ground in the vicinity of a fire when thunderstorms are present.”
The storms were due to pass through much of central NSW, including Coonamble, Dubbo, Orange and Bathurst.
While most inland towns across the state were forecast to see maximum temperatures remain high until the new year, Sydney was expected to see cooler conditions over the weekend and into New Year’s Eve.
After at hot Christmas and Boxing Day, temperatures dropped in Melbourne, with maximums forecast to remain below 30C over the next week.
The cooler conditions on Friday helped firefighters battle an out-of-control blaze in Victoria’s Grampians national park that has scorched 74,000 hectares (183,000 acres) of bushland, roughly the size of Singapore. The fire’s perimeter spans more than 360km.
Difficult terrain and dry conditions were expected to result in the bushfire burning well into the new year.
A low-intensity heatwave warning was also in place for much of Queensland, with some areas facing severe heatwave conditions. The bureau warned of “low to locally severe intensity heatwave conditions” along Queensland’s east coast throughout the weekend.
Brisbane was expected to peak at 37C on Saturday and up to 40C in its western suburbs, before dropping on Monday, with showers forecast until Thursday.
Authorities urged residents to keep cool and hydrated, and to avoid staying in the sun.
Adelaide was forecast to see maximum temperatures rise to 31C across the final days of the year, while Perth and Darwin were expected to have temperatures remain in the low 30s through to Thursday.
Hobart is likely to experience a cooler end to the year, with temperatures under 25C forecast.
