After a record year for wildfires, the American West is hoping for a breather this summer.
The Pacific warming phenomenon known as El Niño, which helped drive global temperatures to a second straight annual record, brought more snow to the peaks of the Rockies, the Sierras, and other Western ranges. As that snowpack melts, it adds moisture to the mountain forests, leaving them less susceptible to fire.
But that moisture has also boosted the growth of grasses and other small plants at lower elevations — creating more fuel in those areas. That points to high risks of wildfire for the Southwest and the lower elevations of California, where dry and windy stretches are likely to raise the odds of a big blaze, and in south-central Alaska, where a reduced mountain snowpack and an early warmup are raising the odds of a big fire.
"Our biggest concern this summer will be the lower-elevation rangelands of the West," Ed Delgado, who runs predictive services for the National Interagency Fire Center (NIFC) in Boise, Idaho, told reporters last week. "With the high fuel loadings and the grass crop, we could see a change in the fire season from the higher-elevation timber country to the lower-elevation rangelands this year."
But at higher elevations and in the northern Rockies in particular, the additional snow is expected to produce a more normal fire season. That doesn't mean there won't be any fires, but the season will start later, said Philip Higuera, who teaches fire ecology at the University of Montana.
"The timing of snowpack is well-linked to the number of large fires we expect to see in the summer. And when snowpack melts, that's what starts the clock ticking as far as allowing fuels to dry out to the point they can burn," he said.
And while most of California is still in the grip of a deep, lengthy drought, "The rest of the West has recovered quite a bit," NIFC spokeswoman Jennifer Smith said.
"It is looking better. Compared to last year at this time, everybody was having a drought throughout the West," Smith said.
The United States saw a record 10 million-plus acres burned in 2015 — a year that cost the federal Forest Service more than $2.6 billion, forcing it to shift resources from other programs that could prevent future blazes. Nearly half of that acreage was in remote Alaska, where authorities could manage the blazes with little danger to people, Smith said.
But the more populated West has been primed for bigger fires by the long-term effects of climate change, experts say. A wildfire north of San Francisco ballooned to tens of thousands of acres within hours of being touched off last September, sweeping through two small towns.
A typical fire season is nearly three months longer than it was in 1970, and there's less water available to fight a blaze. The acreage lost to fires has topped 5 million in 10 of the last 15 years, the Forest Service says.
The expectation is that this year is likely to be closer to the average for most of the West — but average doesn't mean no fires, Higuera cautions.
"The presence of fire itself is not unusual," he said. It's a natural part of the forest environment. But an increase in bigger, more frequent fires over a period of decades does have wildland managers concerned.
In the far north of Alberta, Canada, a fire that erupted May 1 forced more than 80,000 people to flee from the city of Fort McMurray, the hub of Canada's oil sands. That blaze had destroyed more than 2,400 buildings as of Tuesday and could end up being Canada's most expensive natural disaster. That fire was fueled in part by a ridge of warm, high-pressure air that parked over the province of Alberta, leaving the area without significant rainfall for weeks.
Smith said US forecasts don't predict conditions anything like that this summer, but she urged the growing number of people who make their homes on the edge of the woods to take precautions: "Be safe, be smart, and obey the fire bans, if there are any in their area."
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