Firefighters have managed to partially contain a giant wildfire in the Mojave desert that scorched tens of thousands of acres of scrub and sent smoke across the Las Vegas Strip.
The York fire was mapped at roughly 125 sq miles (323.7 sq km) on Tuesday, with 23% containment, making it the largest wildfire of the season in California.
A brief but heavy downpour on Tuesday helped crews battling the fire, but meteorologists warned of the potential for sudden and erratic wind shifts that could endanger crews later on.
The blaze erupted on Friday near the remote Caruthers Canyon area of the vast wildland preserve, crossed the state line into Nevada on Sunday and sent smoke further east into the Las Vegas valley.
Midday Monday, a smoky haze on the Las Vegas Strip obliterated views of mountains surrounding the city and suburbs. Because of low visibility, the Harry Reid international airport in Las Vegas reported departure delays of nearly two hours.
Tuesday brought a 15-minute downpour that helped firefighting efforts, but thunderstorms could pose problems if they pass over the area, said Clay Morgan, a meteorologist with the National Weather Service in Las Vegas.
If the storms miss the flames entirely, crews could face unstable wind conditions – with gusts up to 40mph (64 km/h) – and risk having the fire blown back at them, Morgan said.
Firefighters reported battling “fire whirls” in their struggle to get the flames under control.
A fire whirl – sometimes called a fire tornado – is a “spinning column of fire” that forms when intense heat and turbulent winds combine, according to the National Park Service.
The vortexes – which can be anywhere from a few feet tall to several hundred feet high, with varying rotational speeds – were spotted on Sunday on the north end of the York fire.
“While these can be fascinating to observe they are a very dangerous natural phenomena that can occur during wildfires,” the park service wrote.
To the south-west, the Bonny fire burned about 3.6 sq miles (9.3 sq km) in the rugged hills of Riverside county. The blaze was about 30% contained on Monday evening.
Meanwhile, officials in Washington state said a a new wildfire near Spokane prompted mandatory evacuations.
The Washington state department of natural resources said on Monday that the West Hallett fire started Monday afternoon and had high potential for growth.
KREM-TV reports about 20 homes are threatened. Some people in the area were ordered to evacuate, with others warned to be set to leave.
The American west has seen an usually quiet wildfire season so far, but with significant portions of the region under extreme heat warning, firefighters have warned fire risk is growing.
More than 50 million Americans remain under a heat advisory in one of the hottest summers ever recorded, and a heatwave continues to affect vast parts of the US.
On Monday, Phoenix, Arizona, ended a record stretch of daily highs over 110F (43.3C). The reprieve was expected to be brief, with the forecast predicting highs again above 110F for several days later in the week.
