Torrential rain in New South Wales has reduced the number of active fires in the state by a third, from more than 60 down to 42.
The commissioner of the NSW Rural Fire Service, Shane Fitzsimmons, said on Friday there had been a “dramatic shift” in the hot, dry and windy conditions that have driven the unprecedented fire season for months.
“This has been an absolute welcome disruption to that weather pattern and a massive reprieve and relief to so many people right across New South Wales,” he said.
“Obviously we don’t want to see lots of widespread damage and destruction from flooding, but it is certainly a welcome change to the relentless campaign of hot, dry weather resulting in widespread damaging, destructive fires that we’ve experienced for too long now.”
The RFS is taking advantage of the conditions to strengthen containment lines and, where possible, conduct back-burning operations.
Fitzsimmons said of the 42 fires still burning in NSW, 17 were uncontained.
He said there was optimism that rainfall over the next week would result in many of those being declared contained, and “hopefully going to the status of out”.
Most of the rain has hit fires in the north and northeast of the state.
“It’s certainly not across all the fire grounds at this stage. We’ve seen it concentrated largely up through the north-east of the state, it is slowly moving south-eastwards toward Sydney and parts of the Illawarra,” Fitzsimmons said.
Coastal areas of NSW, including Sydney, could receive their highest rainfall levels in more than three years as a trough makes its way down the state.
Multiple severe weather and flood warnings were in place across the state on Friday, with emergency services warning of possible land slips in areas near fire grounds cleared of vegetation.
The Bureau of Meteorology said Friday could see Sydney receive its largest amount of rainfall over a 24 hour period since 2018, with 60mm to 90mm forecast.
The last time the city had more than 100mm of rain in one day was 28 November 2018.
The city could also receive more rainfall over a three-day period than it has has at any point in the past three and a half years, with 40mm to 90mm forecast for Saturday and another 40mm to 80mm expected on Sunday.
“The last three-day event when we saw rainfall totals potentially this high was 226mm and that was in June 2016,” Dean Sgarbossa, a senior meteorologist, said.
The heavy falls are due to a trough that is making its way from southeast Queensland and northern NSW down the NSW coastline.
Within the trough there are smaller low pressure centres that are leading to intense rainfall over some areas. The BoM said the small scale of these low pressure centres was making precise forecasting of rainfall levels in some areas difficult.
The heavy falls are expected to move into fire-affected parts of the NSW south coast over the weekend. There could also be significant falls in areas with active fires near the ACT and in Victoria’s East Gippsland region.
But those heavy falls come with warnings of water contamination from ash and silt.
Increased run-off could also lead to flash flooding and land slips, which may block access trails and roads in some areas.
WaterNSW has been monitoring areas around the Warragamba Dam, the source of 80% of untreated supply for greater Sydney.
Two silt curtains designed to trap material that could pose a risk to water quality have been in place since January.
Brogo dam, on the south coast, which supplies Bermagui, is also close to a fire ground.
On Friday, the flooding led to road closures in some areas, including several in Sydney.
In the northern rivers region, a car was washed off the road and two people had to be rescued from a caravan due to rising floodwaters.
The road to the Jenolan Caves, south-west of Katoomba, was also closed due to fears the heavy rain could cause landslides.
The RFS said there were still some areas west of the ranges around Canberra, where a number of fires were burning and yet to see rainfall.
Crews were back-burning where possible, but very heavy rain could make that difficult in some places.
However, Fitzsimmons said the wet weather was putting much needed moisture back into the landscape and this would help firefighting efforts, even if hot, dry weather returned.
“We’re certainly not going to have the underlying conditions of such profound moisture deficit and drought situations dominated by this massive heat event that’s been sitting there literally for months,” he said.