While firefighters have their hands full out west, Virginia’s gearing up for the start of a second fire season.
Jeff Koenig has been battling forest fires for 35 years – nearly a decade here in the Shenandoah National Park . Out west, he says, the forest dries out in summer. Not so in Virginia.
“Y’know the leaves coming back on, the green grass, we traditionally have a lot of summer thunderstorms that keep things pretty wet around here.”
But from late February to mid-May, the Shenandoah can be dry. This past spring, Koenig and his colleagues battled five blazes, and now they’re getting ready for a second fire season.
“Late September, early October, the leaves start coming off. We get into our fall fire season which can go into mid-December usually. When we get those strong frontal winds – 40-50 miles an hour – we have our hands full. Is it a simple matter to predict where a fire’s going to go and what’s going to happen? Not so simple.”
William Mahoney agrees. He’s a fire expert at the National Center for Atmospheric Research.
“The complexity of the terrain makes a difference, the type of fuels – whether it’s a crown fire, meaning that the fire is jumping from tree top to tree top or a grass fire which is running very quickly along the ground, and very subtle changes in any of those conditions could have the fire running in directions that are not consistent with blowing down wind.”
And even the speed of a fire can catch smoke jumpers and hot shots by surprise.
“The fact that fires create their own heat, their own thermals, they create their own channeling – you can definitely get swirls and whirls that will actually accelerate it faster than the average wind speed.”
The unpredictability puts guys like Jeff Koenig at risk. Last year, a blaze in Arizona killed 19 firefighters from Prescott.
“The forecast was for afternoon thunderstorms, and as is typical out in the West, when you get a thunderstorm, because it’s dry you do get a lot of precipitation that evaporates and causes cold air to form, and that comes down to the ground very quickly and forms what are called gust fronts. On this particular day, a lot of gust fronts started forming in the afternoon, and gust fronts from the thunderstorms turned the wind around 180 degrees, and the hotshots teams that were kind of on the edge of the burn line were not expecting that wind shift. It was a tragedy!”
To improve predictability, Mahoney and other scientists at the center have spent about twenty years refining sophisticated computer models. Using data from satellites, aircraft, ground sensors and other sources they can better predict where fires may occur and what they might do.
“So we’re hoping in the future that with better fire prediction modeling, we can in the morning or the night before show a picture of what the actual fire behavior could look like, try to identify -- Is this fire likely to exhibit extreme behaviors, blowbacks, splits, fire tornadoes, will there be gust fronts present? -- and at least provide a much better piece of guidance to the entire response team.”
Until then, Koenig and other frontline firefighters remind visitors to the Shenandoah that fires are only allowed in designated picnic and camping areas, and as the forest dries out this fall, people living around it need to be extra careful with any source that could start a blaze.
