Fire Behavior
View article.
The Climate Forecast System Reanalysis (CFSR) is used to provide the meteorological data for calculating the indices. Our results indicate that HDW can identify days on which synoptic-and meso-alpha-scale weather processes can contribute to especially dangerous fire behavior. HDW is shown to perform better than the HI for each of the four historical fires. Additionally, since HDW is based on the meteorological variables that govern the potential for the atmosphere to affect a fire, it is possible to speculate on why HDW would be more or less effective based on the conditions that prevail in a given fire case. The HI, in contrast, does not have a physical basis, which makes speculation on why it works or does not work difficult because the mechanisms are not clear.
View guide.
The Fuels Guide and Database (FGD) is intended to provide fuel loading and vegetation information for big sagebrush (Artemisia tridentata) ecological sites in the Morley Nelson Snake River Birds of Prey National Conservation Area (NCA) in southern Idaho. Sagebrush ecosystems in the NCA and throughout much of the Great Basin are highly influenced by non-native plants that alter successional trajectories and promote frequent wildfires, especially due to fine-fuel loadings that are highly variable over time and space. These dynamic fuel conditions can increase uncertainty when attempting to project fire risk and fire behavior. The FGD was developed to help quantify and assess these dynamic fuel loadings, and it provides access to fuels data across a range of conditions, from relatively intact sagebrush-bunchgrass communities to degraded communities dominated by nonnative annual grasses and forbs. The FGD can be queried for a variety of environmental conditions, and it provides tabular data, reports, and photographic records of fuels based on user queries. This report describes the FGD, including overall data content and data-collection methods, as well as instructions for installing and using the database.
View article.
Through a series of examples spanning at least four research disciplines and three ranges of spatial scale, we illustrate that by precisely defining parameters in a way that holds across scales and relaxing one steady-state simplification, we begin to capture the inherent variability that has largely eluded the fire behavior community. Through exploring examples of “deep interdependence,” we make the case that fire behavior science is well equipped to launch forward into more complex lines of inquiry.
View webinar recording.
Webinar presented by Faith Ann Heinsch, S&K Global Solutions, RMRS Missoula Fire Lab
The webinar described major changes from version 5 to version 6, showed sample Runs demonstrating these changes, provided suggestions for calculating surface fire behavior using BehavePlus v6, described how changes in BehavePlus affect NWCG courses that use this program (e.g., S-490; RX-301/341), and provided ways to get additional information.
View study.
This study examines differences in temperature, vapour pressure deficit, fuel moisture and wind speed for large and small lightning- and human-caused wildfires during the initial days of fire activity at ecoregion scales across the US. Large fires of both human and lightning origin occurred coincident with above-normal temperature and vapour pressure deficit and below-normal 100-hour dead fuel moisture compared with small fires. Large human-caused wildfires occurred, on average, coincident with higher wind speeds than small human-caused wildfires and large lightning-caused wildfires. These results suggest the importance of winds in driving rapid fire growth that can allow fires to overcome many of the factors that typically inhibit large human-caused fires. Additionally, such findings highlight the interplay between human activity and meteorological conditions and the importance of incorporating winds in modelling large-fire risk in human-dominated landscapes.
View report.
The original objective of the study was to determine how ignition, smoldering, and flaming are affected by the age of masticated fuels using a combined field and lab approach.
View webinar recording.
This seminar was presented by W. Matt Jolly and recorded by the USFS, RMRS, Missoula Fire Sciences Laboratory.
View report.
This report is an outstanding complete description of not only the Rothermel model, but also the modifications and addendums that have evolved for supporting the many systems that use the model. This work shows all the equations, discusses their relevance, and illustrates graphically their response to changes in their inherent variables. The variables required for driving the models referred to as inputs, which must be obtained to describe the environment in which the fire is burning, are often misunderstood.
View article.
This study compared fire size, seasonality, and environmental conditions (e.g., wind speed, fuel moisture, biomass, vegetation type) of large human- and lighting-started fires that required a suppression response. Mean large fire size varied by three orders of magnitude: from 1 to 10 ha in the Northeast vs. >1000 ha in the West. Humans ignited four times as many large fires as lightning, and were the dominant source of large fires in the eastern and western U.S. (starting 92% and 65% of fires, respectively). Humans started 80,896 large fires in seasons when lightning-ignited fires were rare. Large human-started fires occurred in locations and months of significantly higher fuel moisture and wind speed than large lightning-started fires.
This mobile-friendly, current, and interactive map combines data from the National Digital Forecast Database and RAWS surface weather observations.