Oak Fire burns over 16,000 acres; number of firefighters quadruples

The number of firefighters now battling the Oak Fire near Yosemite has quadrupled in the last 24 hours.

As of Monday, slightly more than 16,000 acres have burned, the Oak Fire has ballooned in size and is consuming property as it rapidly spreads through parched, drought-stricken land.

Flying embers are creating spot fires, contributing to the growth of the fire.

"Any spots that are flying if they do land into the fuels. Those fuels are so receptive and that's what's causing this fire to grow so, so rapidly and giving us such a hard fight," said Natasha Fouts, a Cal Fire spokesperson.

Another factor contributing to the hard fight is the topography.

"We often utilize bulldozers to put in lines and some of this terrain is just too steep to get dozers in there," said Fouts. "So we're having to use hand crews, which moves a little bit slower, so that's been a big challenge for us." 

In 24 hours, the number of personnel assigned to the firefight has jumped from 403 to 2,093 as mutual aid has been called in from across the state to battle what’s now considered the high-priority fire in the state.

Cal Fire lists the number of structures threatened at more than 2,500, and as the fire grows, so does the number of people being forced out of their homes.

"We just issued more mandatory evacuation orders so that number is probably going to push up to 5,000," said Fouts.

Air quality, northeast of the fire, has rapidly degraded to unhealthy in the area around Lake Tahoe and south. Computer models from the National Weather Service show smoke pushing toward the Bay Area into Monday, but a spokesperson with the Bay Area Air Quality Management District said, even though they’ve issued an air quality advisory, the smoke isn’t expected to rise to unhealthy levels.

"We do expect that smoke to kind of stay aloft and not impact air quality at the ground level here," said Erin DeMerritt with the Bay Area Air Quality Management District.

Cal Fire said weather and smoke have not hampered their ability to attack the fire from the air.

Conditions are expected to remain stable in the coming days, and firefighting may get progressively more difficult as each day develops.

"We'll continue to see in the afternoons as the temperature rises and the humidity drops, that's when we're seeing that explosive fire behavior in the afternoons, late afternoon," said Fouts.

Cal Fire moved its command center Sunday west from Mariposa to Merced, but said the move was not motivated by fire danger. They said they needed more space and nearby lodging to accommodate the growing number of firefighters.