Here is an image of the fires downloaded from the GA Sentinel site. The Esk fires noted in the report are to the far left. It is not clear to me which of the fires mentioned are the largest area in the image. That area of fire appears to be burning in an area of bushland away from any homes, roads etc.
A thick smoke plume is apparent from this fire in the imagery.
Looking at the weather conditions, these fires appear to be largely wind driven. Winds in the regions were quite strong (20-25 kts) this afternoon, with much higher gusts. Temperatures and humidities are fairly modest.