The Emergency Services Agency is warning that the fire in the south of Canberra could spread substantially on Saturday.
In a worst case scenario, the NSW and ACT "fire spread prediction" for February 1 shows the Orroral Fire widening substantially to the east, encompassing Tharwa and covering a large area of the southern parts of the ACT.
"Currently, there is the potential that fire could spread as far north as to Tharwa and close to the southern suburbs of Canberra including Banks," the ACT Emergency Services Agency said.
Residents in danger areas coloured red on the map "may be impacted by fire. If your plan is to leave, leave early and avoid being in these areas during the heat of the day."
ACT Emergency Services Commissioner Georgeina Whelan said hot and windy conditions plus a potential thunderstorm were expected over the weekend.
"If wind conditions prove to be challenging, we could see suburbs such as Conder, Banks and Gordon come under attack from ember attacks on Saturday afternoon," Ms Whelan told ABC radio on Friday morning.
"These are the areas we have been doorknocking for several days now. What people will see is potentially spot fires continue to be ignited forward of the main body of the fire."
The commissioner said those in southern Tuggeranong suburbs who intended to stay and defend their property should have a bushfire survival plan in place and know where to shelter should an emergency warning be issued.
"Our community needs to be clear on what their plan is and understand that plan and take appropriate action to protect themselves," Ms Whelan said.
"On our worst fire day, we won't be able to to put a firetruck on every corner and at every home.
"People need to be alert and not paralysed with fear by the environment around them by the consequences of not being prepared."
The NSW RFS statement says: "Severe fire danger is forecast across south eastern NSW and the ACT for Saturday.
"Under these conditions, a number of fires will spread and may threaten properties. Embers may be blown ahead of fires and could start spot fires."
It says that people in the solid red areas on the map "may be impacted by fire. If your plan is to leave, leave early and avoid being in these areas during the heat of the day.
"The red dotted area shows locations which may experience embers. These may be blown from fires which are currently contained, or from fires as they spread. Watch out for spot fires and be ready to take action. If you choose to stay and are impacted by fire, you may not be able to leave."
On top of that, the big series of fires stretching down New South Wales for about 150 kilometres from Bundanoon nearly to Bega were close to merging on Friday evening. The RFS "fires near me" map showed them joined in a thin line near Kiora.
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