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Surface Fire Behavior Worksheet

Table of Contents for This Page

  1. Available Tools and Resources
  2. Required Surface Model Inputs
  3. Surface Model Outputs
  4. Acceleration Effect on Rate of Spread

This comprehensive worksheet can be used with the surface fire behavior lookup tables, the Nomograms and Nomographs, as well as BehavePlus, and runs if you want a paper copy.

Consider using this as your briefing documentation by including a weather forecast narrative, your thoughts about recent fire activity, your sense of how accurate the predictions seem, and when you expect changes through the burn period.

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Worksheet for recording information collected and estimates produced when estimating surface fire behavior.

Available Tools and Resources

This section describes how to estimate expected surface fire behavior and provides several references tools used in the process:

  1. A Worksheet (above) designed to document a complete assessment for surface fire behavior and growth using either the lookup tables or the nomographs.
  2. EWS Tables for estimating Effective Windspeed from Slope and Midflame Windspeed. The Effective Windspeeds that result from these tables assumes that wind is blowing ± 30° from upslope. For other situations, manual vectoring using the EWS Table would be necessary.
  3. Surface Fire Behavior Lookup Tables for making estimates of surface fire spread and flame length. Note these assumptions:
    • 10-hr and 100-hr moisture values of 6% and 8% are used in the lookup tables.
    • The *20ft/FCST wind line is provided as a convenience, but only works with stated Wind Adjustment Factor (WAF) & no slope adjustments.
    • Backing & flanking columns are only rough estimates based on ½ and 1 mph windspeeds. Use the Flanking and Backing Fire Behavior Nomograph , or BehavePlus for more precise estimates.
  4. Instructions for Surface Fire Behavior Nomographs and Nomograms.
  5. Flanking and Backing Fire Behavior Nomograph for estimating rate of spread and flame length where fire is spreading more slowly on the flanks and at the back of the fire perimeter.

These tools can help you make expected surface fire behavior estimates. Consider the following:

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Required Surface Model Inputs

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Surface Model Outputs

  • Rate of Spread is useful in fireline tactical applications; identifying what is at risk in the burn period, escape route limitations.
  • Flame Length/Fireline Intensity is used generally in determining what tactics make sense during the peak burn period, interpreting safety zone concerns, and suggesting spotting potential.
  • Heat per Unit Area is available from nomograms and BehavePlus. Like the Energy Release Component, it may be helpful in suggesting burn duration and fire effects.

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Acceleration Effect on Rate of Spread

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Fire Spread Acceleration. Fire spread accelerates over a period of time after initiation. The period of time varies based on the fuelbed.

Fire acceleration is defined as the rate of increase in fire spread rate. It affects the amount of time required for a fire spread rate to achieve the theoretical steady state spread rate given 1) its existing spread rate, and 2) constant environmental conditions.

Because initiating fires can take 20 minutes to over an hour to reach a steady spread rate, fire behavior and fire growth can be significantly reduced in the first burn period, and when beginning to spread in subsequent periods.

At this time, fire acceleration is implemented only in FARSITE, using the model developed for the Canadian Forest Fire Behavior Prediction System (Alexander et. al. 1992).

It is active by default, but can be turned off as a model input.

As implemented, inputs are segregated by type of Ignition (point vs. line source) and potentially by fuel type (grass, shrub, timber, slash, a default, or by fuel model). Grass fuels are expected to have more rapid acceleration rates (shorter time to reach equilibrium) than fuel types with larger woody material (slash, etc.).

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NWCG Latest Announcements

NWCG Equipment Technology Committee Releases New Equipment Bulletins

Date: September 27, 2024
Contact: Equipment Technology Committee

The Equipment Technology Committee (ETC) has released three new Equipment Bulletins:

  • ETC-EB-24-003 Diesel exhaust fluid (DEF) in fuel containers.
  • ETC-EB-24-004 Two-compartment fuel and oil container (Dolmar) unavailable in the United States (US) and reminders for upkeeping current inventories.
  • ETC-EB-24-005 Personal Protective Equipment (PPE): Inspection, Care, and Maintenance.

These bulletins remind field going personnel of important issues related to equipment for wildland firefighting efforts.

References:

NWCG Alerts

ETC-EB-24-003 Diesel exhaust fluid (DEF) in fuel containers

ETC-EB-24-004 Two-compartment fuel and oil container (Dolmar) unavailable in the United States (US) and reminders for upkeeping current inventories

ETC-EB-24-005 Personal Protective Equipment (PPE): Inspection, Care, and Maintenance

The Experiential Learning Subcommittee is looking for your feedback on Staff Rides

Date: September 20, 2024
Contact: Ashleigh D'Antonio and George Risko, Leadership Committee

The Experiential Learning Subcommittee needs to hear from the field about where the greatest need lies regarding staff rides and their accessibility.

  • Do you have an event you would like to turn into a learning experience?
  • Do you have a staff ride built, but are struggling to implement the delivery?
  • Do you need help building capacity?
  • What other ideas do you have to support experiential leadership training?

Fill out this short survey below to help us help you.

References:

Staff Rides: Feedback

Staff Rides

Updated NWCG Single Resource Casual Hire Information, PMS 934

Date: September 19, 2024
Contact: Incident Business Committee

The Incident Business Committee has updated the NWCG Single Resource Casual Hire Information, PMS 934. This update expands the provisions for hiring emergency personnel.

References:

NWCG Single Resource Casual Hire Information, PMS 934

IBC Memorandum 24-03

NWCG 2024 Spring/Summer Highlights

Date: September 13, 2024

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Welcome to our latest highlights from the National Wildfire Coordinating Group, where we explore the latest updates, insights, and efforts that develop interoperable wildland fire operations among federal, state, local, Tribal, and territorial partners.

The Performance Support Package, which for ABRO includes the Incident Position Standards and Next Generation Position Task Book were developed through the Incident Performance and Training Modernization (IPTM) effort. The Performance Support Package will support trainees, those qualified in the position, and evaluators.
 

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NASA JOINS NWCG!

The National Aeronautics and Space Administration (NASA) is officially an associate member of NWCG. As such, NASA is beginning to collaborate with wildland fire management agencies with the goal of increasing collaboration across agencies and leveraging NASA data, technology, and innovation for nation-wide efforts in wildland fire management. NASA has a rich history of research, development, and technology transfer in the areas of Earth science, space technologies, and aeronautics that support the NWCG mission.

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WWW.NWCG.GOV HAS A NEW LOOK AND DESIGN

The NWCG web team dedicated the past two years to making a significant upgrade to the www.nwcg.gov site. This upgrade involved a comprehensive redesign of over 7,700 web pages.

The modernization of NWCG’s website involved migrating to Drupal 10, a cutting—edge content management system, and leveraging Amazon Web Service GovCloud for secure and efficient hosting. These upgrades help ensure that the NWCG website remains current in content management practices, offering enhanced customization, improved performance, and an overall superior user experience.

NWCG Leadership Committee

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WFLDP PRP book covers

The Wildland Fire Leadership Development Program announced the Professional Reading Program’s 2024 list!

The years books include:

  • Young Men and Fire by Norman Maclean
  • The Wisdom of the Bullfrog by William H. McRaven
  • The Art of Clear Thinking by Hasard Lee
  • Emotional Agility by Susan David
  • Writing to Persuade by Trish Hall

Learn more at the NWCG Leadership Committee

INCIDENT PERFORMANCE AND TRAINING MODERNIZATION

In 2023, NWCG kicked off the Incident Performance and Training Modernization (IPTM) effort. A training system overhaul focused on developing a performance-based training system designed to shift training to on-the-job when appropriate.

Over the next five years, NWCG intends to analyze all positions within the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1. To date we are currently working on 30 incident positions, and planning for 20+ in calendar year 2025.

Subject Matter Experts from a variety of geographical areas and agencies recently completed the position analysis for 16 positions. From this analysis, Incident Positions Standards and a Next Generation Position Task Book will be developed for each position.

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Incident Performance and Training Modernization

NEXT GENERATION POSITION TASK BOOK

In April 2024, NWCG launched the new Next Generation Position Task Book (Next Gen PTB) which is a key component of the IPTM effort. This revised evaluation tool is designed to work in conjunction with the newly developed Incident Position Standards.

Major Next Gen PTB changes:

  • Structured to improve constructive conversations between evaluators and trainees.
  • Reference new Incident Position Standards.
  • Include only tasks required to be evaluated for successful performance.
  • Trainees will be rated on their performance vs. initialing whether a task was completed.
  • Must include written feedback when trainee does not meet the standard.
  • Will be position specific (no combined PTBs).
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NWCG’s training course catalog is now available on the Wildland Fire Learning Portal (WFLP).

To access the training course catalog, visit WFLP and either set up an account or login as a guest.