Winds and lightning strikes have sparked and fanned wildfires across the Pacific Northwest this week, including the largest fire currently burning in the US, which has been rapidly expanding near the Oregon-Idaho border.
The Durkee Fire near Huntington in Oregon, has scorched 1,600 sq/km, an area more than half the size of Rhode Island's land mass, authorities said.
It is threatening several towns.
The blaze was set off by lightning on 17 July, and wind gusts up to 100 kph drove the flames across brush, timberland and ranches, killing hundreds of cattle.
The fire was only 20% contained yesterday, officials said.
While there is zero chance of rain through next week, winds have dropped and cooler air is in store, said meteorologist Marc Chenard of the National Weather Service.
"Hopefully it gives firefighters a break," he said.
As of Thursday, wildfires this year have burned almost 400,000 hectares in Oregon and 125,900 acres in Washington, according to the Northwest Interagency Coordination Center in Portland, Oregon.
In 2020, the worst year in recent memory, Oregon wildfires scorched more than 1.14 million acres, according to a tally by CBS TV affiliate KOIN.
A large, fast-moving and rapidly growing wildfire in northern California forced more than 4,000 people to evacuate as firefighters battle gusty winds and perilously dry conditions, authorities said.
Fuelled by a crushing heatwave, the so-called Park Fire - the most intense wildfire to hit the state this summer - has rapidly devoured nearly 240,000 acres as of last night and is continuing to gain strength.
"This fire has been rapidly expanding 4,000 to 5,000 acres an hour," incident commander Billy See said at a press conference yesterday evening.
For now, it is "zero percent" controlled, despite the efforts of some 1,700 firefighters, according to state agency Cal Fire, with hundreds of additional resources ordered on the way.
A total of 4,000 people have been forced out of the towns of Cohasset and Forest Ranch, plus an additional 400 from the small city of Chico, due to the fire.
The blaze has so far destroyed 134 structures, authorities said.
Despite the structure losses, Butte County Fire Chief Garrett Sjolund said, "many more have been saved".
"It is a fire that is challenging our strategies, but we are finding opportunities to deploy our resources in successful ways," Mr Sjolund told reporters.
The fire started on Wednesday near Chico, in Butte County, and within hours had devastated a wide area there and in neighbouring Tehama County.
In just two days, the Park Fire has already become the 20th largest fire in California history by land area.
The blaze has generated an enormous column of dense grey smoke, with gritty clouds akin to those of a violent storm now visible in nearby US states.
Fire departments from across the state have sent crews to lend a hand.
The National Weather Service issued a Red Flag Warning for the region through last night, predicting "critical" fire weather conditions.
On Thursday, police detained a 42-year-old man on suspicion of having started the fire by pushing a burning car into a ravine.
Smoke from fires in western Canada and the Pacific Northwest have brought hazy skies and unhealthy air from the Rocky Mountains to Minneapolis and as far east as Detroit, weather reports said.
Denver had the worst air quality in the US yesterday and ranked the 30th worst in the world, according to IQAir, a group that tracks air pollution across the globe.
Much of the smoke coming into the central and eastern US comes from a raging wildfire in the mountainous Jasper National Park in the Canadian province of Alberta.
The park and the town of Jasper, which draws more than two million tourists a year, were evacuated on Monday, displacing 10,000 residents and 15,000 park visitors.
As much as half of the structures in the town could be damaged or destroyed, officials said, as the blaze burned more than 89,000 acres as of late Thursday.
Videos posted on social media show entire streets levelled by the blazes in the Alberta province, with scorched trees, charred metal remains of cars and nothing but rubble where homes and businesses had stood.
