For anyone who’s spent time in the woods of northern Arizona lately, it’s pretty obvious how extreme the fire danger is right now. Vegetation is dry, stock tanks are low, and in some areas large-scale tree die-offs are a vivid reminder of the drought that’s plaguing the Southwest. In the midst of the region’s driest months of the year, many residents are growing nervous and officials are on high alert. KNAU’s Ryan Heinsius recently met up with True Brown, fire management officer with the Coconino National Forest, to check out the conditions firsthand.
True Brown: It is very dry right now. We’re currently in very high fire danger. That’s the current conditions on the ground right now, but we’re also in, really across the western U.S. particularly in the Southwest right now, in a severe to exceptional drought pretty much across the Southwest as a whole. So, as we were just walking in here you can just hear it on the ground, all those needles and sticks just crunching and cracking, really very little moisture in the fine fuels on the ground right now. But things are kind of browning out with the grass here right now, and our indices, our predictors of fire behavior, and just what we monitor on a daily basis just based on weather conditions, fuel moistures, are all on the upswing as we get into the heart of our fire season.
Ryan Heinsius: When you say fine fuels, could you actually show me what you’re talking about here on the ground? What are we looking at here?
TB: Really what we’re looking at is some of these finer fuels, and just picking up a clump of needles and what we like to see is for them to bend before really breaking, but as you can see with these needles here right now, as soon as you put just a little bit of pressure on them they just break right in front of us. That’s really indicative of just how little moisture is in those fuels. And folks can see this in their own backyards after a rainstorm. Grab a bunch of needles and you’ll be able to bend them almost in a complete circle, which just shows how that moisture really affects that and how fast the wind and sun really dry out the ground fuels. And these are the primary carriers of fire as it moves across the landscape here in the Southwest in this ponderosa pine stand that we’re looking at right now.
RH: Maybe you could tell me about the specific scientific metrics that go into determining how dry a forest is and how dangerous it might be for wildfire.
TB: Some of the primary ones that we’re looking are the energy release component and then the burning index. Really those are indicators of if we were to get a fire, what kind of fire behavior would be exhibited with that burning index. Kind of a rough rule of thumb is, the burning index, you take that number and, it varies considerably, but we’ll take that number and then divide it by 10 and that gives us roughly what our flame lengths are going to be on the ground each day. So for example, if we had a BI of 65 for the day we would be looking at potential flame lengths out here right now in this fuel type of about 6-and-a-half feet. And that gives us an indication of when we do respond to a fire, what we’re going to need to respond to it, because that 6-and-a-half-foot flame lengths, I mean, that’s taller and I am right now. And a lot of the time that means we’re going to be using resources more looking at heavy equipment and looking at more aviation resources to help try to suppress those fires.
RH: Looking ahead to the next weeks or months, what are we looking at? Could this potentially be worse that previous years?
TB: There is always that potential, Ryan, and that is something that we are very concerned about and we’ve been talking about for quite some time. After last year, and effectively having two years of the non-soon as everybody’s liking to call it these days, and then really a very poor winter when it comes to snowpack, this year could shape up to be a very challenging fire season with how dry it is across the Southwest. You know, really, where we’re at too is a couple weeks ahead of where we were last year. We are looking at some pretty significant fire events if we do get the wrong start in the wrong place at the wrong time of day it’s going to be a challenge for sure. And that’s something we’re looking at really across the Southwest right now.