Lightning-sparked wildfires in Northern California have spread to become some of the largest in state history, forcing thousands to flee and destroying hundreds of homes and other structures as reinforcements began arriving to help weary firefighters.
At least 100,000 people are under evacuation orders. Fire crews made slow progress Saturday battling some of the largest wildfires in California history — thanks to improved weather conditions and additional resources coming from others states.
But danger loomed with the threat of thunderstorms and lightning forecast for Sunday that could spark new fires and overwhelm firefighters battling hundreds of fires throughout the state.
"The worst is not behind us, we are in a battle rhythm," California Department of Forestry and Fire Protection Chief Thom Porter tweeted.
Light winds, cooler and more humid nighttime weather and more equipment arriving for firefighters helped them make their most significant progress battling three massive Northern California fire "complexes" -- multiple wildfires in one area being treated as a single incident. They have burned 1,045 square miles (2,700 square kilometers).
The fires that started this week have killed five people, destroyed nearly 700 homes and other structures and forced tens of thousands from their houses.
California Wildfires
Diane Brickley comes back home to take care her goats after she was evacuated as the Apple Fire burns nearby in Cherry Valley, Calif., Saturday, Aug. 1, 2020. A wildfire northwest of Palm Springs flared up Saturday afternoon, prompting authorities to issue new evacuation orders as firefighters fought the blaze in triple-degree heat. (AP Photo/Ringo H.W. Chiu)
California Wildfires
A mouse runs as flames flare at the Apple Fire in Cherry Valley, Calif., Saturday, Aug. 1, 2020. A wildfire northwest of Palm Springs flared up Saturday afternoon, prompting authorities to issue new evacuation orders as firefighters fought the blaze in triple-degree heat.(AP Photo/Ringo H.W. Chiu)
California Wildfires
A tanker makes a drop on the Lake Fire which has rapidly grown to more than 10,000 acres north of Los Angeles, Wednesday, Aug. 12, 2020. (David Crane/The Orange County Register via AP)
California Wildfires
A helicopter makes a water drop over the Ranch Fire, Thursday, Aug. 13, 2020, in Azusa, Calif. Heat wave conditions were making difficult work for fire crews battling brush fires and wildfires across Southern California. (AP Photo/Marcio Jose Sanchez)
California Wildfires
An air tanker drops retardant while battling one of several wildfires comprising the Deer Zone fires a unincorporated Contra Costa County, Calif., on Sunday, Aug. 16, 2020. Firefighters scrambled to contain multiple blazes, sparked by widespread lightning strikes throughout the region, as a statewide heat wave continues. (AP Photo/Noah Berger)
California Wildfires
A helicopter carries water to drop onto the River fire near Salinas, Calif., Sunday, Aug. 16, 2020. (AP Photo/Nic Coury)
California Wildfires
A flag flies as flames from the LNU Lightning Complex fires crest a ridge Tuesday, Aug. 18, 2020, in Napa County, Calif. The blaze went on to destroy multiple homes near Lake Berryessa. Fire crews across the region scrambled to contain dozens of blazes sparked by lightning strikes as a statewide heat wave continues. (AP Photo/Noah Berger)
