Weather & the Prescribed Burn Plan
Photo caption: A wildland fire fighter uses a drip torch to ignite the Magic Feather Prescribed Burn near Red Feather Lakes in June 2021. (Photo credit: Evan Barrientos)
Colorado’s overgrown forests are malnourished – starving for the cyclical, low-intensity fire that sustained them for thousands of years. This weakened condition makes them the ideal food for wildfires, and ironically vulnerable to destruction by a too-intense version of the very thing they need. So, like good cooks in the kitchen, our local fire management experts craft recipes that will feed them: prescribed fire plans. The goal: Provide proper food to as many acres of forest as conditions will allow, and strengthen them before wildfire moves in for a buffet.
Every prescribed fire plan is a unique recipe of specific and precise conditions that must be in place prior to ignition. Customized for the unique components, conditions, and needs of each individual burn unit, ingredient choice is guided by fuel types and density, soil moisture, topography, aspect, access, infrastructure, natural fire breaks, safety, and project goals.
Weather Rules Them All
Like broth to a good soup, the primary plan ingredient is the weather. It’s the single most critical variable before and during prescribed burns. Weather details hold the whole project together, guiding the process and results. All other burn plan components connect to and pivot on precise humidity, temperature, wind direction and speed, cloud cover, or sunshine. When the plan and conditions align and stay put, critical work gets done. For example, the Bighorn Sheep Prescribed Burn of 2019 was planned for late February in the Poudre Canyon because conditions would be cool enough to burn snow-free south-facing slopes, while snowy north-facing slopes provide a barrier to fire spread. The weather and snowpack matched the recipe, the project was completed, and the goals of improving wildlife habitat and removing hazardous fuels were met. If there had been any unexpected weather fluctuations beyond approved conditions, fire personnel would have halted further ignition, initiated a holding pattern, or transitioned to mop-up procedures. The pot would have immediately been pulled off the stove and the heat turned off.
Covering Ground: Variety Is The Spice of Success
You might think that no wind means good weather for prescribed fires, but a breeze can be an essential ingredient for project completion and is often required in a plan. The right kind of wind disperses smoke and keeps flames moving across the landscape. Diverse weather and site conditions at different project locations on any given day bring flexibility to prescribed fire scheduling, allowing as much work to get done as possible before wildfire season. If the conditions are forecast to shift out of prescription for one project, it can mean that they’ll actually end up matching the recipe for another where work can proceed.
Reghan Cloudman, Forest Service Public Affairs Specialist for the Canyon Lakes Ranger District, emphasizes these benefits and explains that “Just because we see certain conditions in downtown Fort Collins doesn’t mean those same conditions exist where the burns are taking place. Wind speed and temperature here can be vastly different from where you see smoke. Change allows us to go with the project that requires the conditions that we’re anticipating.”
The Many Measuring Cups
In the days before a project is scheduled to begin, fire professionals scrutinize spot forecasts from the National Weather Service to confirm that conditions will indeed match the recipe. Once ignitions begin, conditions are continuously observed, monitored and measured using handheld and onsite instruments, along with information relayed in real-time from fire meteorologists. Nourishing low-intensity flames are then fed to our fire-reliant ecosystem in bite-sized pieces. They chew through heaping platters of fuel buildup as a safe, manageable alternative to intense ravenous wildfires fed by our warmer, drier climate.
The human factor of experienced observation adds another layer of accuracy to high tech weather monitoring methods. No one is more attuned to weather than wildland firefighters. After years of training, observing, and anticipating situations that can mean life or death, many have developed a reliable intuitive relationship with the ever-changing atmosphere. It’s rumored that they can measure relative humidity with one deep breath, or sense a wind shift with a tilt of the head – the perfect skill set for safely delivering a healthy, hot meal to our needy forest.