Thunderstorms Complicate California Wildfires

Hundreds of Californians were evacuated from their homes Sunday after a rare thunderstorm sparked several wildfires.

Firefighters said 4,500 buildings are at risk as they contend with scorching heat and unpredictable winds in the Angeles National Forest.

A similar thunderstorm in Northern California sparked small fires and knocked out power in the San Francisco Bay Area.

California's also experiencing a heat wave and massive power outages during all this. The agency that controls the state's power grid issued a statewide emergency for the first time in nearly 20 years.

Things got even more complicated for firefighters when 15 mile-per-hour winds started pushing flames uphill, on rugged terrain, amid lightning strikes and record heat. Wind gusts reached 75 miles per hour.

Near the town of Loyalton, California, firefighters witnessed perhaps the most extreme event from these wildfires so far: a collision of a massive cloud, high winds and fire that formed a tornado-shaped spiral of flames.

Many of the state's wildfires remain largely uncontained with more strong winds still in the forecast.