He said this had "given us the break we need".
The wind would pick up to 40km/h this afternoon.
Mr McNamara said a forest fire couldn't be contained with just aircraft.
"The only way you can get a fire like this out is to get the crew on ground to kill it.
"There's no way you can get a fire out with aircraft as you can't get underneath it and break it apart," he said.
He said firefighters along with heavy machinery, heavy tankers and pumps would be on ground today.
Mr McNamara estimated about 30 per cent of the fire was contained at present.
"It's looking really good."
He credited the pilots and firefighters for their work.
"It's a dangerous job but we can do it safely if we keep to the rules of looking after each other," he said.