The start of fire season has been declared in Yosemite National Park due in part to warm, dry conditions that include daytime highs in the 90s in Yosemite Valley through Wednesday this week.

“You expect the heat sometimes, but the dryness is what’s really getting to our forests,” said Gary Wuchner, a fire information specialist for the Park Service. “Right now the relative humidities are reflecting the fact it’s dry as well as hot.”

Fire personnel in the park planned to begin defensible space inspections in Aspen Valley, Hodgdon Meadows, Foresta, El Portal and Wawona on Monday. They inspect about 600 residential and commercial properties annually, Wuchner said.

‘Year-round fire season’

For people who live at lower elevations in Tuolumne and Calaveras counties, peak fire season is expected to be declared June 20, Chief Josh White of Cal Fire’s Tuolumne-Calaveras Unit said Monday.

White emphasized the Tuolumne-Calaveras Unit has been in perpetual fire-season readiness since 2014 due to multiple consecutive years of drought.

Cal Fire in Tuolumne and Calaveras counties staffed up from five engines to 13, with more crews and bulldozers available on weekends, on April 18. All aircraft at Columbia Air Attack Base became available May 9.

Stations at Skull Creek and Hermit Springs got staffed May 19, with two more engines bringing the Tuolumne County unit’s engines up to 15 total.

“On June 20th we will be staffing an additional six engines” for a two-county total of 21, White said in an email. “These engines are the second engine at every two-engine fire station. As I write this, we have one additional engine staffed due to the above-normal temperatures.”

Weekend fire

There were no prescribed burns, lightning fires or any other active fires in Yosemite as of Monday afternoon, Wuchner said.

There was a fire caused by someone in the valley on Saturday, and two engines responded, and contained it, he said.

The cause of the fire was being investigated, Wuchner said.

The Soupbowl prescribed fire project in Wawona has been postponed indefinitely. First, fuels in the project area were too wet. Then a high-pressure atmospheric condition set in, which would have affected air quality, Wuchner said.

Intended to reduce hazardous fuels in mixed conifer forest in and around Wawona, it may be completed this fall.

‘Decent winter’

There’s still snow melting at some high-elevation locations in Yosemite, Wuchner said. Flows for waterfalls, streams, creeks and rivers may peak sometime this week as snowmelt runoff crests.

“We had a decent winter, but the snowpack is pretty much gone now below 6,000 feet,” Wuchner said. “There’s still some on north-facing slopes above 7,000 feet.”

With warm, dry conditions over consecutive days this week and last week, grasses and other vegetation at lower elevations have started drying out. Residents and homeowners are urged to clear a defensible space of 100 feet or to property lines around homes and other structures to reduce fire hazards.

Wuchner said fire personnel and equipment in Yosemite this fire season include one hand crew, four Type 3 wildland engines, one helicopter and fire management staff.

No pile burning

Pile burning is discontinued throughout the park until further notice, Wuchner said.

Fire management staff urge visitors to make sure all campfires have been extinguished with water, mixed with ashes, and are out cold.

Don Coffman, fire marshal for Yosemite National Park, said residents of Yosemite Valley are not required to follow state code for defensible space.

“Fire danger in the valley is relatively low, in part because of the flat topography on the valley floor,” Coffman said.

Along the Highway 49 corridor this week, daytime highs are expected in the mid-90s through Wednesday and in the 80s Thursday and Friday. Overnight lows are expected in the 60s tonight and in the 50s through Saturday.