The largest firefighting force in NSW history will be mobilised today.
Statewide more than 3000 firefighters will be dispatched with 90 aircraft on standby.
About 700 of those volunteer firefighters trudged into base camp at Penrith Panthers yesterday afternoon, ready to battle the blazes threatening Blue Mountains communities.
The NSW Rural Fire Service established a base camp in the grounds of Panthers on Monday to accommodate about 700 volunteers who have driven or flown in from around the country to help.
Base camp coordinator Inspector Tim Butcher of the NSW Rural Fire Service said 220 volunteers arrived on Monday night and by this morning their ranks would have swelled to about 700.
''They're here partly to relieve and, more importantly, to reinforce the locals,'' he said.
''They've come from all around NSW, from as far as the north coast zone based at Tweed, as far west as Dubbo and down south to Eden.
''There are also crews from the South Australian CFS, CFA Victoria and Queensland RFS.''
''They'll be here for at least one week, and then depending on the fires.''
Superintendent Butcher said the staff and management at Penrith Panthers in Mulgoa Road, had been very supportive.
''They have been absolutely fantastic,'' he said.
''They have bent over backwards to help.''
As Superintendent Butcher prepared for today's expected onslaught, volunteers unpacked equipment and supplies from shipping containers.
Pallets of pillows and blankets were unloaded by volunteers driving forklifts, while others forged friendships with colleagues from other brigades, drank coffee and enjoyed yesterday evening's cool and rain while they could.
When Fairfax spoke to Ryan Hoschke of Orana (near Coffs Harbour) yesterday afternoon, he was keen to get to work.
''We got here [Monday],'' he said.
''Hopefully we'll be going up [the mountains] tonight.''