A large uncontained bushfire in the Hunter Valley has been upgraded to an emergency warning level.

The blaze near Salt Ash, north of Newcastle, was downgraded to a Watch and Act alert overnight but that warning has been lifted due to wild winds.

More than 1300 hectares of bushland has been burnt already and the fire is showing no signs of slowing down.

A brand new air tanker and water bombing helicopters have been helping to fight the flames from the sky, as more than 180 firefighters work from the ground.

The 737 Large Air Tanker ‘Gaia’ has been in action in the Hunter this afternoon – the first time this kind of plane has been used to fight a fire anywhere in the world. It’s provided valuable support to firefighters on the ground. #NSWRFS #nswfires #avgeek pic.twitter.com/qHnbcddFpe

— NSW RFS (@NSWRFS) November 22, 2018

Crews are in position on the south side of the fire, ready to protect homes that are under threat.

These conditions are expected to continue through the day…meaning residents need to monitor the situation and act on their bushfire survival plans.