Unpredictable thunderstorms with high winds and lightning have been threatening the efforts of firefighting crews battling a Montana wildfire, dubbed the Roaring Lion Fire, in the Bitterroot National Forest. More than 500 families were evacuated from the area due to the blaze, which destroyed 16 homes and burned more than 8,300 acres.
About 800 firefighters were on hand to battle the blaze, in addition to aerial resources. According to the National Interagency Fire Center, Canada also deployed a Convair 580 to support U.S. wildfire operations in the area.
Lightning is believed to have sparked four new blazes, and fire officials warn that sudden downdraft winds from the base of a thunderstorm, known as “microbursts,” can cause trees to fall with little to no warning. (See related article, “When Lightning Strikes: Wyoming Wildfires.“) These dangerous downdrafts often lead to “extreme fire behavior.”
Extreme fire behavior has the greatest potential to put firefighters at risk. It’s characterized by rapid fire spread, intense burning, presence of fire whirls, and a strong convection column. According to the National Fire Protection Association (NFPA), “Under these levels of fire behavior characteristics, direct control is no longer possible.”
“There are myths about the safest place to be. The actual answer is in a vehicle or a building. There is no other safe place.” – Fire Information Office Mike Cole
“Every time a (lightning) strike shows up on the map, when we see things like that coming toward the fire, we pull off and have crews go to their vehicles,” U.S. Forest Service fire information officer Mike Cole said. “There are myths about the safest place to be. The actual answer is in a vehicle or a building. There is no other safe place,” he added.
And if the thunderstorm includes pouring rain, getting back up to the fire line can be a slippery mess. In addition, a torrential rainstorm may not be the help firefighters are looking for. If this is the first rain in a while, most of it will be lost to run-off.
It can also create an incredible amount of smoke, without truly dousing the hotspots.
What’s needed is about 24 hours of continuous — or near continuous — light to moderate rain. That’s the ideal precipitation for extinguishing a wildfire blaze.
The Roaring Lion Fire is expected to burn through the end of September, according to InciWeb.
Evacuees returning home have been advised to proceed with caution and to watch out for fire-weakened trees, as even those that appear healthy can fall with little or no warning.