The fire is burning in the area of Mellong and moving in a northerly direction towards Putty.

"Fire activity has reduced after a southerly wind change moved over the fireground," the Rural Fire Service stated at 3.15am on Wednesday morning.

A watch and act alert means there is a still a heightened level of threat and the fire remains out of control.

Putty Road remains closed between Milbrodale Road and Long Weeney Creek trail.

AN emergency warning alert has been issued for the Gospers Mountain bushfire with the giant blaze burning within four kilometres of Putty.

Extreme fire conditions and strong winds have fanned the blaze towards the east on Tuesday.

"The fire is threatening the areas north of Culoul and south of Fleetwing," the warning by the NSW Rural Fire Service (RFS) states.

"Fire activity is increasing in the areas of Mellong, St Albans and Upper MacDonald."

The NSW RFS' advice:

The Putty Road is closed from Colo River to Grey Gums.

What you need to do

If you are threatened by fire

THE Gospers Mountain fire could travel significantly towards the east on Tuesday afternoon, a predictive fire map shows.

The NSW Rural Fire Service's (RFS) map shows under that under the extreme fire danger risk, and with predicted southerly winds on Tuesday afternoon, the fire had the ability to spread significantly.

"Fire activity is increasing in the areas of Mellong, St Albans and Upper MacDonald," the NSW RFS alert states.

The RFS' advice for people in these areas if that they plan to leave the region due to the bushfire, that they should leave now.

If your life is at risk call triple-0.

RESIDENTS in Mellong, St Albans and Upper MacDonald near the Wollemi National Park who plan to leave in case of a bushfire should leave now, the NSW Rural Fire Service (RFS) says.

The Gospers Mountain fire burning through the Wollemi National Park has grown to 30,417 hectares and is being spread by strong winds in an extreme fire danger day.

"Fire activity is increasing," the NSW RFS said in its alert to residents.

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"If you are in the area of Mellong, St Albans and Upper MacDonald, and your plan is to leave, leave now to a safer location.

"A safer location may include a built up area, well away from bushland."

The Putty Road is closed from Colo River to Grey Gums.

The fire currently is listed at 'advice' level and being controlled.

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The Lithgow local government area is experiencing extreme fire danger on Tuesday with NSW RFS operation officer Brett Taylor warning that fires burning under these conditions cannot be stopped.

Meanwhile, all state forests are closed with Lithgow TAFE and Blackheath Public School closed on Tuesday.

NSW Rural Fire Service Commissioner Shane Fitzsimmons said there are volatile fire conditions right across the state.

"We can expect pretty significant fires to break out ... whatever fires we get that start under those winds will burn very aggressively," he said.

Check and follow your Bushfire Survival Plan. If you do not have a plan, decide what you will do if the situation changes. Leaving early is your safest option.

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