Conflagrations like the 1871 Peshtigo have reemerged as important threats across North America and around the world. Understanding the factors and the phenomena that produced the fire environment of that day is possible because of weather observations collected and recorded at the time and studies of extreme fire behavior that continue to this day. Recounting it should be a cautionary tale for our lives as we continue to live them.
Here, we focus on the elevational distribution of forest fires in mountainous ecoregions of the western United States and show the largest increase rates in burned area above 2,500 m during 1984 to 2017. Furthermore, we how that high-elevation fires advanced upslope with a median cumulative change of 252 m (−107 to 656 m; 95% CI) in 34 y across studied ecoregions. We also document a strong interannual relationship between high-elevation fires and warm season vapor pressure deficit (VPD). The upslope advance of fires is consistent with observed warming reflected by a median upslope drift of VPD isolines of 295 m (59 to 704 m; 95% CI) during 1984 to 2017. These findings allow us to estimate that recent climate trends reduced the high-elevation flammability barrier and enabled fires in an additional 11% of western forests. Limited influences of fire management practices and longer fire-return intervals in these montane mesic systems suggest these changes are largely a byproduct of climate warming. Further weakening in the high-elevation flammability barrier with continued warming has the potential to transform montane fire regimes with numerous implications for ecosystems and watersheds.
No significant change was projected for the number of human-caused fire ignitions, but we projected a 14% reduction in lightning-caused ignitions under future conditions. Mean fire sizes were 31% and 22% larger under future conditions (2031–2060) for human and lightning-caused ignitions, respectively. All but one climate model projected increased frequency of record-breaking events relative to the contemporary period, with the largest future fires being about twice the size of those of the contemporary period. This work contributes to understanding the role of lightning- and human-caused fires on future fire regimes and can help inform successful adaptation strategies in this landscape.
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The Pack Creek Wildfire, ignited by an abandoned campfire, started early in the fire season on June 9, 2021 in the Pack Creek Day Use Area on the Manti-La Sal National Forest.
Under the influence of down-slope, down-canyon winds, the fire made a push west and down Pack Creek. The fire quickly exploded as a crown fire through a riparian area composed largely of cottonwood trees and pinyon and juniper landscapes. Within the community, fuel breaks implemented by Forestry, Fire and State Lands (State of Utah, FFSL) were designed to act as intermittent catch points for firefighters to actively engage the fire.
Large wildfires need four key ingredients to burn, not just one. Ignitions, fuels, and drought thresholds must be crossed at the same time, enhanced by anomalous weather events such as foehn winds. But how do these ingredients, or drivers, fit together in various ecosystems? In this important concept paper, Pausas and Keeley (2021) outline the mechanistic flow of these complex drivers for fire prone ecosystems and illustrate this in the figure below (Fig.1). In brief, the fire weather for a given ecosystem helps to push the other three essential driver thresholds, or saturation points, down. With ignitions, fuel continuity, and drought saturation points simultaneously lowered by the right weather, wildfire will be triggered.
WindNinja, a tool developed by RMRS scientists, delivers high-resolution wind predictions within seconds for emergency fire responders making on-the-ground decisions. The program computes spatially-varying wind fields to help predict winds at small scales in complex terrain. These predictions are extremely important in fire-prone landscapes where local changes in the near-surface wind are not predicted well by either operational weather models or expert judgment but are extremely important for accurate fire behavior predictions.
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Description: Compare and view up to 5 Weather Scenarios to evaluate effects on fire behavior. Only in the Interagency Fuel Treatment Decision Support System (IFTDSS) can you run fire behavior models and compare the outputs side-by-side. Easily view on the map, change the inputs and re-run to explore the impacts of weather on fire behavior outputs. Great for enhancing your burn plans, NEPA documents or understanding and calibrating model outputs.
Description: This free online symposium for researchers and fire managers will highlight the latest advances in using soil moisture information to better understand and predict wildfire danger. These recent discoveries are revealing the potential for soil moisture estimates from in situ monitoring stations, remote sensing, and models to improve fire danger predictions and to advance our understanding of fire behavior. This interactive symposium will provide researchers and fire managers a unique opportunity to connect with others, to learn about ongoing research in this area, and to discuss ways to move forward with new research and end uses.
John Bolten, Hydrological Sciences Branch, NASA Goddard Space Flight Center
J. D. Carlson, Biosystems and Agricultural Engineering, Oklahoma State University
Nicholas Coops, Forest Resources Management, University of British Columbia
W. Matt Jolly, Rocky Mountain Research Station Fire Sciences Laboratory, U.S. Forest Service
Brian Magi, Geography and Earth Sciences, University of North Carolina at Charlotte
Brad Quayle, Geospatial Technology and Applications Center, U.S. Forest Service
J. T. Reager, Terrestrial Hydrology Group, NASA Jet Propulsion Laboratory
Angela Rigden, Earth and Planetary Sciences, Harvard University
Description: The idea of using sensors to remotely measure things is not new. Aerial photos taken from hot air balloons were first proposed as a tool for mapping streets in the 1850s. In 1941, a US Forest Service ranger developed a technique for mapping fuels with aerial photos. Recent advances in remote sensing have dramatically increased the amount of spatial information that can be generated for a given area. This webinar will look at some of the ways the Fire and Environmental Research Applications Team at the Seattle Fire Lab is using remote sensing to measure fuels and fire behavior. We’ll also discuss how this information can improve our capacity to model fires.
Presenter: Jim Cronan is a forester at the Pacific Wildland Fire Sciences Lab in Seattle, WA. He coordinates field data collection for scientists on the Fire and Environmental Research Applications Team and has been involved with research on fuels and fire behavior for 20 years.
Rapid advancements in wildland fire modeling are promoting innovations in how we characterize and map wildland fuels. Before these models can be widely used, more research on fuel characterization and mapping methods is needed to support3D model inputs. The 3D Fuels Project is characterizing surface and canopy fuels on pine-dominated sites in the southeastern and western United States and western grasslands that represent fuels commonly characterized for prescribed burning. Through this project, researchers are developing a library of tools and datasets to leverage multi-scale estimates of 3D fuel structure and consumption that can be used directly within models of fire behavior and smoke production.