The weather bureau has upgraded its forecast for hot northerly winds on the Aberfeldy fire in Gippsland for Thursday.
The bureau is now predicting northerly winds on Thursday morning, easterlies in the afternoon and back to hot northerlies overnight Thursday and Friday.
The South west change is now expected later, about midday on the fire-ground.
The fire travelled about 50 kilometres from Aberfeldy to Glenmaggie last Friday burning 22 houses and scores of sheds and outbuildings.
Towns on the southern edge of the fire from Walhalla across to Coongulla could be under threat with the northerly winds.
Some rain is possible with the change on Friday.
Further east crews are still trying to round up a series of fires near Orbost started by lightning late yesterday but the main effort remains on the southern containment lines of the growing Aberfeldy fire.
The upgraded weather comes as fires services diverted aircraft away from the .
Fire crews have about 36 hours to do as much work shoring up containment lines.
Emergency crews closer to Melbourne, may have been caused by machinery sparks.