Powerful wind gusts, extremely low humidity and the threat of dry lightning are fueling an outbreak of large wildfires across the Southwest.

The largest fire in the United States has marched through thousands of acres of tinder-dry forest in Utah, fueled by conditions that fire managers and experts call unprecedented.

Extreme heat watch in U. S: A cold front on Sunday will bring winds that could push the fire in new directions before the weather starts stabilizing next week