Larry Bradshaw was riding his motorcycle down U.S. Highway 12 on Monday afternoon when he noted the building smoke and stiffening winds.
It was an acute observation for a meteorologist who has worked at the U.S. Forest Service’s Fire Sciences Laboratory in Missoula since 1992, and still maintains the National Fire Danger Rating System.
Bradshaw tuned into the scanner a few hours later and listened as chaos unfolded ahead of the West Fork II fire, the blaze jumping the highway he’d ridden hours earlier before making a run east down the Lolo Creek Canyon.
“The winds were really strong out of the west,” said Bradshaw. “The inversion broke there earlier than it did in Missoula.”
When it comes to wildfires, scientists at the fire lab have seen bigger and faster moving, though they admit the Lolo Creek Complex is drawing attention due to its visibility, and that it’s burning in what has become a wildland-urban interface.
The 1988 Canyon Creek fire and its 26-mile run through the Scapegoat Wilderness comes to mind, along with the Red Bench fire that same year in Glacier Park. The Hayman fire in Colorado covered 19 miles over one day of burning in 2002 before destroying 133 homes.
With the Lolo Creek fires billowing outside their office window near the airport and retardant bombers making a steady run, Bradshaw and Mark Finney, a research forester with the Fire, Fuel and Smoke Science Program, noted how late-summer conditions aligned to give the fires room to grow.
“It was the same recipe used on every fire – it’s dry and it’s windy,” said Finney. “We have a canyon situation and a couple fires low in the canyon. The fires have topography working in their favor – the canyon topography helping with the winds.”
The tools used by fire managers to predict the interaction of wind, topography, weather and fuel were developed here by the likes of Bradshaw and Finney and dozens of other scientists working up and down these hallways, part of the government’s Rocky Mountain Research Station.
On his computer, Finney pulls up the Wildland Fire Decision Support System, a database of all active fires burning across the nation. The Lolo Complex is listed among them, and software developed at the Missoula research lab came close to predicting the fire’s early potential, including its jump across Highway 12 and the push north and east.
“They enter all the fuels, weather and topography, and they dial up a simulation and this program runs it,” Finney said. “This was run pretty early on, but even then it showed the fire getting north of the creek. It shows the fire’s potential.”
There are places in the world – Australia primarily – where glowing embers can drift 15 miles and ignite spot fires downwind. With their long and twisted filaments, Finney named eucalyptus embers as being particularly capable of long and sustained drifts.
The fuels in Montana can also drift several miles. Residents in the South Hills of Missoula found blackened ash the size of dollar bills landing in their yards after Monday’s blowup. Lolo National Forest officials reported active spotting more than two miles downwind from the fire that evening while briefing the governor.
“When humidities are in the teens, spotting is a very real problem,” Finney said. “In our forests here, most of the embers tend to be small twigs, round and glowing. They don’t last for long, but they may go several miles in extreme conditions.”
Finney brings up the energy release component – an index based on the energy potential of fuels as related to dryness. Known as the ERC, it isn’t as high this year as last, Finney notes, and many fires haven’t experienced the run or intensity made by the Lolo fires this week.
But the recipe for fire hasn’t changed since the dawn of man – fuel, oxygen and heat. Yet the science behind the study of fires has jumped light years ahead, thanks to new technology and the work of the Rocky Mountain Research Station.
“It’s the same old ingredients – there’s nothing new here,” Finney said. “The thing we have to realize is that fires are inevitable. They’re impossible to completely exclude from the landscape.
“By trying to do that and doing it so successfully, what we’ve done is saved up the fires for the worst conditions. When you get rid of all the fires under moderate conditions, all you have left are the extreme ones.”