Smoke from two fires burning near Yosemite National Park sent air quality plummeting to very unhealthy levels in Carson Valley over night.
Fire.airnow.gov sensors are reading an air quality index of 246, indicating people should limit or avoid outdoor activity in places around the Valley.
A Gardnerville Ranchos sensor is indicating unhealthy conditions of 165, which includes a recommendation to reduce outdoor activity.
Visibility was down to 2 miles at Minden-Tahoe Airport at 7:35 a.m. Sunday.
Most of the smoke is being generated by the Oak Fire, which grew to more than 14,000 acres, more than doubling in size over the last 24 hours, with no report of containment.
The fire destroyed 10 structures and damaged another five in Mariposa County about 100 miles due south of Carson Valley.
More than 2,000 firefighters were working on the fire as of Sunday morning, including 51 hand crews, 225 engines and 17 helicopters.
The cost of fighting the fire is up to $1.6 million. The cause is still under investigation.
A dozen miles east of the Oak Fire, the Washburn Fire remains at 79 percent containment as it smolders through the duff and fallen trees within its perimeters. Smoke from the Oak Fire is actually helping cool down conditions near the fire lines on the Washburn.
Smoke is expected to continue drift north through the day, which combined with hot temperatures will make life miserable for residents without air conditioning.
A new fire is burning 100 miles due south of Carson Valley is forecast to send smoke into Western Nevada tonight as the wind shifts.
The Oak Fire is burning a dozen miles west of the Washburn Fire in Yosemite National Park.
Smoke from the fire was visible from Western Nevada on Friday night, according to National Weather Service forecasters in Reno.
“The … smoke model suggests near-surface smoke will advect over the eastern Sierra as westerly Zephyr winds develop through the afternoon into the evening hours,” forecasters said on Saturday morning. “Southeasterly flow at mid-levels will push any vertically integrated smoke northward into the Tahoe Basin and Western Nevada overnight tonight, though visibility and air quality impacts should be minimal in those areas.”
Fire.airnow.gov sensors in Carson Valley are reading in the good range this morning but could indicated deteriorating air quality as the day wears on.
The Oak Fire grew from 60 to more than 6,000 acres since the first update on Friday afternoon with no report of containment as of Saturday morning.
“Fire activity is extreme with frequent runs and group torching,” according to a CalFire update. “Vegetation is very receptive to new spot fires due to hot, dry weather and drought. Heavy fuels, strong winds and low humidity are also influencing fire behavior.”
Federal fire mapping indicated that the fire could spread across almost 12,000 acres and is threatening more than 1,000 homes.
Nearly 400 firefighters were working the blaze as of Saturday morning, with 11 hand crews.
With the Washburn Fire at 79 percent containment, firefighters working that blaze are starting to demobilize, according to Saturday’s National Interagency Coordination Center situation report.