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A state of Emergency has been declared in NSW as parts of the state face the most dangerous combination of warm, dry weather and strong winds in more than 40 years as major bushfires swep the state.
"We're planning for the worst but hoping for the best", Premier Barry O'Farrell told reporters, flanked by Rural Fire Service Commissioner Shane Fitzsimmons.
Rural Fire Service Commissioner Shane Fitzsimmons wrote to Premier Barry O'Farrell today requestingthe move.
Mr O'Farrell says there are concerns the weather conditions would deteriorate significantly over the next few days, with the potential for a significant and widespread danger to life and property across the State.
The declaration triggers a range of measures, including allowing emergency services to direct the public to evacuate or to order power and gas supplies be shut off.
On Sunday, fire crews ramped up containment efforts around several of the blazes with the weather forecast to deteriorate and officials warning of "unparalleled" dangers.
More than 200 homes have already been destroyed and another 120 damaged by the wildfires.
One man has died so far trying to protect his property.
Firefighters had a reprieve on Friday and Saturday with an easing in the weather, but containment and property protection efforts were stepped up on Sunday ahead of an expected intensification in weather conditions set to include warmer temperatures and 100 kilometre per hour (60 mile per hour) winds.
New South Wales Rural Fire Service Commissioner Shane Fitzsimmons said there would be several extremely difficult days ahead for fire crews.
"We've got what would be unparalleled in terms of risk and exposure for the Blue Mountains and Hawkesbury communities throughout this week," Fitzsimmons told reporters.
14:00 The RFS has told residents at Mt Wilson and Mt Irvine not leave their homes - it is too late to do so safely. After telling residents of Bell to flee the same State Mine fire, residents are being told they may be isolated for days.
The FIre Service earlier said that conditions are deteriorating with temperatures rising, humidity dropping and dry winds from the northwest to return.
13:30 The Rural Fire Service has released this linescan image of the Hall Road in the NSW Southern Highlands fire taken at 12:30PM - red means more active.
An emergency warning has been issued for a bushfire burning east of Lithgow - the State Mine Fire - as fire crews spend another day battling blazes across the state.
The community of Bell is being advised by the RFS to leave now, if not prepared.
A Total Fire Ban remains in place for Greater Sydney.
RFS Commissioner Shane Fitzsimmons told the media on Sunday morning that crews are facing "a very changing, a very dynamic, volatile situation that’s going to continue to unfold."
He says the focus today in the Blue Mountains is the Bells Line of Road west of the township of Bilpin, as conditions deteriorate on Sunday.
He said the conditions being faced have not been seen since the late 1960s; the fires are 'in a whole new ball game, and a league of their own.'
NSW Premier Barry O'Farrell says the state will get through this crisis, 'not just due to the magnificent people fighting the fires' but because of the implementation of plans. He's called on people to continue to listen to authorities.
From AAP: About 200 firefighters from Queensland, Victoria, Tasmania and the ACT are helping tackle the Blue Mountains fires which have claimed more than 200 homes.
Easing conditions overnight have allowed the Rural Fire Service (RFS) to downgrade bushfires at Springwood and Mount Victoria and the State Mine fire in the Blue Mountains, as well as the Balmoral bushfire in the Southern Highlands, to a `Watch and Act' level.
But temperatures and winds are expected to pick up from Sunday afternoon and a total fire ban is now in place across Sydney, the Hunter region, Shoalhaven, the Central Ranges and the Illawarra.
Temperatures this afternoon are expected to rise into the 30s and strong winds are predicted, but they will not be as severe as those experienced on Thursday.
Earlier, Fitzsimmons bunkered down with specialist forecasters from the Bureau of Meteorology and will brief Premier Barry O'Farrell at RFS headquarters later on Sunday.
"I'm increasingly concerned about the potential for significant fire runs and consequential damage if the weather conditions materialise like they're indicating they could over this week," he told the Seven Network.
About 200 firefighters have travelled to the firegrounds from interstate and that number could be boosted.
"We're looking at bolstering that number ... particularly in light of what's expected to be some pretty deteriorating, awful conditions over the coming days," Commissioner Fitzsimmons said.
He's paid tribute to the firefighters and volunteers who have worked to protect lives and homes from the major blazes that broke out on Thursday.
"(We've got) men and women doing some pretty extraordinary work. Time and time again you're hearing extraordinary stories of what they were being confronted with, decisions and actions that they took," he said.
"They've all got each other's back and right at front of mind, they're trying to do all they can for their local communities."
The Bells Line of Road has been closed in both directions between Tadrosse Lane and the Great Western Highway. Between Mount Victoria and Bell, the Darling Causeway was also closed in both directions on Sunday morning, and buses were replacing trains on the Blue Mountains Line between Lithgow and Mount Victoria.
At Wilton, Picton Road has been closed between Macarthur Drive and the M1 Princes Motorway. Motorist have been urged to avoid all bushfire-affected areas and drive with extreme caution in areas that are experiencing heavy smoke and poor visibility.