A rapidly growing wildfire in Utah surged overnight, driven by intense heat and strong, dry winds that forced more communities to evacuate, officials said Saturday.

Air tankers and helicopters were unable to operate Friday as winds intensified around the Cottonwood Fire, now the largest active wildfire in the United States. 
Gusts reached 45 mph and humidity levels dropped into the single digits, creating extremely dangerous fire conditions.

With the blaze spreading quickly through the treetops, firefighters had limited options to slow its advance