The father-of-three, whose family voluntarily left the area, said he first learned of the fires on Sunday evening [US time] when he saw flames encroaching down the valley towards a friends house and winery.
"I drove down to see if he was awake and aware of what was going on and ended up staying there. Twelve of us turned up and pretty much saved his house and winery."
The group kept hoses on structures to keep them wet and used a bulldozer to dig out fire roads, he said.
"The fires came all the way down the hill. We kept them about 20 metres from the structures, but properties next door just went up in flames. It was pretty crazy.
"It's heartbreaking because you know that its somebody's everything. I've got a lot of friends who have lost everything - particularly from the Sunday night fires, because no one was prepared for it and they started up around 10.30pm."
The 45-year-old, who works for Goosecross winery in Napa Valley, said many people had mere moments to pack before they evacuated.
"They just grabbed what they could and got out. They lost everything. We all got told to pack bags to grab everything and go."
Nancarrow was among those who chose to stay in the smoke-filled region and help others.
"There's some pretty tough and resilient people around here and people are banding together and helping each other out."
