The Werri Berri fire has breached the Snowy Mountains Highway with a two-kilometre firefront, RFS Community Liason Officer Greg Potts says.
"It's made a run through grassland across the highway in the Mogilla area," he said.
"The Snowy Mountains Highway is closed between the Princes Highway intersection north of Bega to the Princes Highway-Mogilla intersection.
"This means people should not be travelling on the highways. If you are in Bega, stay in Bega and delay travel."
An emergency warning text has been sent to people between the Princes Highway, Snowy Mountains highway, Candelo, Bega Road and Buckajo Roads.
It is possible the firefront will impact Buckajo, Springvale, Kameruka, Desert Creek and Candelo Roads area.
"We are asking anyone who receives an SMS to read it carefully and note localities and follow advice," Mr Potts said.
"Weather conditions are unfolding as forecast. So far there are reports of a southerly wind on the Victorian border, but it has not reached any of our firegrounds yet."
There have been some small electricity brown-outs reported in Bega. Bodalla is without power. The Coondella fire is "reasonably settled".