UPDATE 11.43 PM SATURDAY

The NSW fire crisis has been made much worse by a gusting wind change from the south that turned blazes south of Wollongong toward population centres, fire authorities have warned.

On the South Coast, the Ulladulla Civic Centre has been opened for emergency accommodation as the wind-whipped flames besieged Milton.

RFS commissioner Shane Fitzsimmons said a man was missing in the Dargan area near Lithgow after telling passing firefighters he intended to stay and defend his home.

He has not been seen since, while his home was reportedly destroyed.

Authorities have confirmed four firefighters have been injured fighting out-of-control blazes in the state, with one hit by a car on the Bells Line of Road. Paramedics treated the firefighter, who was not seriously injured.

According to the Rural Fire Service, the latest day in NSW’s prolonged trial by fire saw “dozens” of homes and structures.

To the west, the energy output of infernos at Currowan and Tianjara grew so intense they have spawned their own fire-driven thunderstorms — a freak condition known to happen only with the most intense fires.

A fire-generated thunderstorm has formed over the Currowan & Tianjara fires in the Shoalhaven, and another may form over the Gospers Mountain fire. This is a very dangerous situation. Monitor the conditions around you and take appropriate action. #nswfires #nswrfs pic.twitter.com/b1kiNNkB2e

— NSW RFS (@NSWRFS) December 21, 2019

As firefighters braced for gusts of up to 80kph, the crisis intensified in Lithgow, where at least five properties were destroyed at McKellars Park, on the town’s northern outskirts, several vehicles destroyed and one person unaccounted for.

By later on Saturday night, RFS officials were saying “dozens” of homes and buildings had been destroyed, though they were unable to provide precise numbers as the wind-driven fires continued adding to their tally of destruction.

Fire crews worked to defend other properties in the area as the Gospers Mountain “mega fire” continues to spread.

Gospers Mountain was elevated to emergency warning level at 12:10pm, and people in Bilpin, Kurrajong Heights, Hartley Vale, Bell, Clarence and Dargan have been told it is too late to leave.

Smoke conditions have greatly hampered operations, obscuring the ability to spot fresh outbreaks and wreathing roads in such dense cover that emergency vehicles can move only at the slowest speeds. In Canberra, umpires were forced to suspend play ion the Big Bash League.

The umpires have met and decided to halt play due to the smoke at Manuka Oval #BBL09 pic.twitter.com/LuXL0fyToc

— KFC Big Bash League (@BBL) December 21, 2019

As greater Sydney sweltered with record breaking temperatures, authorities urged families to “put your travel off” as the heatwave set a catastrophic fire danger level in New South Wales.

At a press briefing on Saturday morning, police and emergency services said ember attack up 10km or more from a main fire front is possible under catastrophic fire conditions on Saturday.

The wind change is expected to extend that range, with smouldering fragments perhaps being carried as far as 20km.

By 2pm, there were SIX emergency warnings for out-of-control fires in Grose Valley, Gospers Mountain, Green Wattle Creek, Tianjara and Currawon.

The NSW Rural Fire Service said ember attack was impacting parts of the township of Lithgow at 2.30pm from the Gospers Mountain fire, issuing an emergency warning for residents to seek shelter.

As the Grose Valley Fire approaches the Bilpin Fruit Bow at Bilpin on Saturday, the NSW RFS warned of increased fire activity in Blackheath. Photo: AAP

NSW Traffic issued an alert that the Great Western Highway – which links Sydney to Bathurst – was closed in both directions for two hours.

Several other highways and roads including the Hume and Princes Highway have since been closed in both directions.

For all major road closures, go to the Live Traffic NSW website.

Multiple fires have jumped to #Emergency Warning levels.
A strong southerly change is bringing difficult & dangerous conditions across fire grounds. The change is due at #Nowra mid-afternoon #Sydney early evening & will continue up the coast https://t.co/8XbejZYhlp @NSWRFS pic.twitter.com/Etk1188a9S

— Bureau of Meteorology, New South Wales (@BOM_NSW) December 21, 2019

Meanwhile, in South Australia, a second person has been confirmed dead after a day of devastating bushfires which led to 15 homes being destroyed along with other buildings and significant losses to stock and crops.

Premier Steven Marshall said one person died in the Charleston area of the Adelaide Hills where the most significant fire continues to burn.

It follows the death of a man in a road crash at Lameroo, which sparked a fire there while noted SA horse trainer John Glatz is in the Royal Adelaide Hospital with significant burns suffered while trying to protect his Adelaide Hills property at Woodside.

As well as the 15 homes destroyed across SA, 28 other buildings have also been lost along with 16 cars.

“My fear is this is only the tip of the iceberg. We haven’t had a chance to get back in to assess the damage,” Mr Marshall said.

Exhausted but determined firefighters from across NSW, interstate and overseas including Canada are currently working on 111 fires in NSW, with fears fire fronts could be pushed further with Saturday’s horrific conditions.

“That is the sort of scale that we are talking about. The profound effect that the drought is having on the landscape and on the flammability of the vegetation cannot be overstated.

“Under the conditions we are expecting today, that is the scale we are talking about and we’ll see what the day brings,” NSW RFS commissioner Shane Fitzsimmons said.

One volunteer firefighter told the ABC many brigades had been fighting fires for up to six weeks.

“They are extremely tired. We manage their mental health by trying to give them a day off whenever we can, but we are an active brigade of 51active members and so we try to share the load around as much as we can, but unfortunately when you’ve got crews out 24 hours a day, that’s rally hard to do.

“At the moment they are running on pure adrenaline. Most of our very experienced people are on the fire ground. Everyone is out there doing whatever they can do and hoping that we do have whatever is available to us to fight this today,” she said.

NSW RFS Deputy Commissioner Rob Rogers urged people to think about about not driving if you don’t need to, and if you’re in a heavily vegetated area and have to go down a single road, think about staying as major roads continued to be closed throughout Saturday afternoon.

“Firefighters will do their best to look after your house but we just want to get through the day with lives in tact.”

“Think very carefully about staying in that area.

“And maybe, not necessarily evacuate, but go somewhere else in the heat, go to the beach, go to a shopping centre, go somewhere that’s not bushfire prone.

Already thousands of firefighters, including 2000 volunteers, are working in shifts to battle over 100 fires in extreme conditions across NSW.

Just over a day after two fellow volunteer firefighters died, Geoffrey Keaton, 32, and Andrew O’Dwyer, 36, the Horsley Park Rural Fire Brigade were back fighting blazes on Saturday.

The rest of the 68-strong brigade put aside their grief to get back on their trucks and help battle blazes.

NSW premier Gladys Berejiklian said the death of Mr Keaton and Mr O’Dwyer had rocked them and their families.

“Especially after the tragic loss of Geoff and Andrew yesterday, our heart goes out to the volunteers who are in the field today,” Ms Berejiklian said.

Catastrophic fire danger Greater Syd, Illawarra/Shoalhaven & Sthn Ranges, & statewide total fire ban. People in areas of Catastrophic areas should avoid bush fire prone areas, identify locations e.g. large towns, cities, shopping centres. https://t.co/6tqOye7ksB #nswrfs #nswfires pic.twitter.com/1vxFVKyLys

— NSW RFS (@NSWRFS) December 20, 2019

There is fear that the Princes Highway south of Nowra could be closed because of several fires in the region including the Currowan blaze.

A catastrophic fire danger has been declared for greater Sydney, the Illawarra and Shoalhaven regions and southern ranges where several significant fires are burning, including some of which are out of control.

Authorities remain particularly concerned about the Gosper Mountain fire in the Wollemi National Park which was on Saturday morning upgraded to an ’emergency warning’ level.

It has already burned almost 450,000 hectares and joined up with two other fires last week, creating a so-called mega blaze.

“Areas around Kurrajong Heights, Bowen Mountain, Bilpin and where that fire gets to around Kurrajong Heights, when the southerly change starts pushing that fire north, we’re worried about the impact of areas there,” Mr Rogers said.

The RFS said they were also concerned about the Grose Valley fire in the Blue Mountains, warning that it could hit Blackheath.

Advice – Grose Valley (Blue Mountains LGA)

If you are in the area of Hat Hill Road or Pulpit Rock, you may experience increased fire activity, embers and smoke.

Embers can be blown ahead of the main fire front, starting spot fires that may threaten property in the area. #nswrfs pic.twitter.com/HsNom8Ivdu

— NSW RFS (@NSWRFS) December 20, 2019

The Green Wattle Creek fire in the Southern Highlands is expected to affect areas in Bargo, Balmoral, Hill Top, Pheasants Nest, Colo Vale and could run all the way down to Mittagong.

Over 200 additional trucks from the NSW Fire and Rescue Service and RFS have been allocated on Saturday and residents are being urged to be prepared to leave.

New South Wales ambulance Commissioner Dominic Morgan at the RFS headquarters said heat-related conditions were up 34 per cent on the same time last year, warning people with respiratory conditions that Saturday’s heatwave could be life-threatening.

“I do want to stress that this was done as a pre-planning exercise. It went very well yesterday. More than 500 people were relocated. The simple reality is that it takes 4-6 hours to relocate that many people.

“With the catastrophic conditions, it was assessed that we really needed to move quicker because the fires are likely to move very quickly today [Saturday].

-with AAP