Images posted to social media show ominous bright orange skies and thick smoke wafting across roads and towns throughout the region.
It warned that some blazes were creating their own weather conditions and that fire clouds — which can produce lightning without rain — were developing.
“These (fire clouds) are extremely dangerous. Do not be caught in the open,” the NSW RFS said.
Fitzsimmons said the fire service has received reports that several communities have been impacted by the blazes, including reports of injuries to residents and damage to buildings.
The “high concentration of fire and extreme volatility and extraordinary fire behavior” was being driven by a “drought stricken landscape” and hot, dry, windy conditions,” he said.
Winds are set to be “relentless” throughout the evening, Fitzsimmons added.
In a tweet Friday, Rob Rogers, Executive Director Operations at the NSW Rural Fire Service described the fires as “unprecedented” and asked residents to “avoid fire affected areas.”
About 50 bushfires are also blazing in the neighboring state of Queensland. Residents in several areas there have been told to evacuate as emergency-level fires threaten homes and properties.
Queensland and New South Wales are prone to wildfires in spring and early summer, and this year’s blazes follow Australia’s hottest summer on record, which brought worsening drought, bushfires and very low rainfall.