Hot dome burns through mountain snow in western US, warning issued for fire season

The mountains that typically receive the most snowfall in March have turned brown this year, thanks to the spring heat dome that kept the western US warm for much of the second half of March. This is raising alarm bells for the fire season, which is already on the rise.

“Everything across the West is headed toward a potentially catastrophic fire season … warning signs are flashing,” said John Abatzoglou, a climate science professor at the University of California Merced.

a heat wave Relaxed over the weekend after Temperatures remain constant between 30 and 40 degrees Celsius – 11 to 17 degrees Celsius above normal for several days in some states.

a search Released on 20 March Found that such a heat wave would be “virtually impossible” without climate change caused by human CO2 pollution, primarily fossil fuels.

Heat records were broken in March in more than a dozen states, causing snow to melt rapidly in the mountains of the western US.

The rapid melting of ice has been linked to long fire seasonBecause it dries out the landscape and provides more time and opportunity for fires to ignite and spread, said Jared Bialik, a research scientist at Western Colorado University in Gunnison, Colo.

But if snow cover was less before the snow quickly melted, that doesn’t mean more forest area burned. The risk of very severe fires also increases – reducing the likelihood of forest regeneration after a fire, Bialik finds in a new study. Published last week.

This is bad news, considering Monday, Snowpack at almost every western US ski destination was on track to be the lowest on recordAccording to Daniel Swain, a climate scientist at the University of California, Los Angeles.

And not just at ski resorts — across much of the western U.S., Abatzoglou said, snowpack is at its lowest level in 20 to 30 years.

Amid record-low snowfall, fire season has begun

Colorado, where Bialik lives, saw record low snowfall throughout the winter. And by Friday, when he spoke to CBC News, it was almost all gone. Balik said it’s the first time he’s seen snow melt this fast in his decade of living in the area, and one and a half months earlier than normal.

This has given the fire season an edge in both colorado and neighbors nebraska.

“Colorado is now covered in smoke from the Nebraska fires,” Bialik said. By Monday, they had already More than 25,000 hectares of land was burnt.

there is also a forest fire Reported in California. most have been still small and in grasslands, but Abatzoglu said he suggests the grass in the area is now dry enough to extinguish the fires.

Where he is in central California, temperatures were over 30 C for several days, and vegetation that is usually green in the spring was turning brown. “It’s extremely hot,” he said Friday. “My air conditioner has been on for the past week.”

How low snowfall causes extremely intense wildfires

Bialik’s research shows that conditions now could lead to more severe fires later.

The U.S. Department of Agriculture keeps track of the amount of water held in snowpack during the winter—which is important not only for crops, but also for forests at the end of the year.

“It provides the water that trees depend on during their growing season,” Bialik said. Less snow means drier, more flammable trees – and more serious fires. His team demonstrated this by combining satellite measurements of snowpack with satellite measurements of forests before and after wildfires over several fire seasons.

“We were surprised that there was such a strong relationship between declines in snowfall and burn severity in the subsequent fire season.”

In less severe fires, he said, the fire can burn dead wood on the forest floor, leaving mature trees intact.

On the other hand, massive fires in dry forests destroy everything, including the seeds that help the forests regrow.

“This creates an opportunity for other types of vegetation to invade the system and replace the forest that was there,” Bialik said. It can be possible Convert forest to grassland or shrublandThis is changing how much carbon is stored in the landscape, he added, and impacting the availability of water and wildfire habitat.

What can be done to reduce the risk?

Whereas Long-term declines in snowpack are being seen due to climate change Across North America, Bialik said, “It’s not all doom and gloom… every winter is another opportunity to get snowpack.”

The study found that climate change may lead to more low-snow years, but weather patterns such as El Nino and La Nina still bring snowy winters from time to time.

And those years, Bialik said, “are an excellent opportunity to do prescribed burning.” This can reduce the amount of fuel available for wildfires, reducing their severity, and such intentionally set fires are easier to contain and control in wet years.

Does this apply in Canada?

Hossein Bonakdari, Professor at the University of Ottawa, Recently used satellite and drought data to look at the factors behind severe wildfires Which devastated more than 8,000 square kilometers in Manitoba last May and how they could have been predicted.

This followed unusually low snow cover, which caused the snow to melt quickly, and an early heat wave that brought record temperatures of up to 37 °C in Winnipeg in May.

Bonakdari said that in Canada, like the U.S., low snowfall is a major risk factor for wildfires, especially in the West. However, he said other factors, such as overall heat and drought, may be more important in the boreal forest.

Bonakdari said much of Canada has been in drought conditions for the past few years Abnormally warm temperatures expected in 2026 due to El NinoMany parts of Canada are still at risk of severe fire season, even if the recent US heat wave has not crossed the border.

Meanwhile, in the US, Abatzoglou is concerned about how widespread the heat wave is – and therefore how fire danger is increasing.

“It’s essentially the entire region of the western United States,” he said. This makes it unlikely that states will be able to borrow firefighting resources from other regions.

But Abatzoglu said it’s not too late to change the risks: “I’m expecting rain in April.”