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Surface Fire Behavior Worksheet

  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

ETC/RMC Safety Bulletin: 25-001 New Guidance on Laundering Wildland Fire Clothing to Reduce Contamination

Date: Aug 8, 2025
Questions? Please contact:
Equipment Technology Committee
 Risk Management Committee

The Equipment Technology Committee (ETC) and the Risk Management Committee (RMC) have issued Safety Bulletin 25-001: Laundering to Decontaminate Wildland Fire Clothing. Recent research revealed that wildland fire flame-resistant pants and shirts can be contaminated with chemicals from combustion byproducts, including carcinogens, and that common laundering practices can effectively remove these harmful contaminants from wildland firefighter clothing more effectively than previously understood. It is recommended to decontaminate wildland fire clothing as frequently as possible. 

Frequently Asked Questions about this new information and how to implement recommendations can be found on the NWCG Alerts page. Read the complete ETC/RMC Safety Bulletin: 25-001 to learn more. 

References:

NWCG Alerts

ETC Safety Bulletin: 25-001

Frequently Asked Questions (FAQ) on Laundering to Decontaminate Wildland Fire Clothing

Equipment Technology Committee

Risk Management Committee

FAQ Now Available for Archiving Type 1 and Type 2 Incident Positions

Date: Aug 6, 2025
Questions? Please contact:
Incident and Position Standards Committee

To support the transition to Complex Incident Management (CIM), NWCG will archive all Type 1 and Type 2 Command and General Staff (C&G) position qualifications in January 2026, as outlined in NWCG Executive Board Memo 25-002. To assist with this transition, a new Frequently Asked Questions (FAQ) document is now available.

This resource answers common questions about the status of Type 1 and Type 2 qualifications, impacts to incident qualification management, training requirements, and resource ordering considerations. Review the full FAQ to learn more.

For additional information on CIM and the transition of C&G positions, see NWCG Executive Board Memos 23-005, 24-005, and 25-002, as well as the Incident Workforce and Development Group webpage.

References:

NWCG Type 1 & Type 2 Position Archiving FAQ

NWCG Executive Board Correspondence

Incident Workforce Development Group

Incident and Position Standards Committee

Incident Position Standards and the Next Generation Position Task Books Now Available for UASD, UASM, UASL and UASP

Date: July 31, 2025
Questions?  Please contact:
Interagency Fire Unmanned Aircraft Systems Subcommittee
 

NWCG is excited to announce that Incident Position Standards and the Next Generation Position Task Books are now available for all four Unmanned Aircraft Systems positions:

  • Unmanned Aircraft Systems, Data Specialist (UASD)
  • Unmanned Aircraft Systems, Manager (UASM)
  • Unmanned Aircraft Systems, Module Leader (UASL)
  • Unmanned Aircraft Systems Pilot (UASP)

The Performance Support Packages for these positions were developed as part of the Incident Performance and Training Modernization effort. These resources support trainees, qualified personnel, and evaluators in their respective roles.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

References:

NWCG Unmanned Aircraft Systems, Data Specialist Position Page

NWCG Unmanned Aircraft Systems, Manager Position Page

NWCG Unmanned Aircraft Systems, Module Leader Position Page

NWCG Unmanned Aircraft Systems Pilot Position Page

Incident Position Standards and the Next Generation Position Task Books Now Available for RADO and INCM

Date: July 30, 2025
Questions?  Please contact:
Incident Logistics Subcommittee
 

NWCG is excited to announce that Incident Position Standards and the Next Generation Position Task Books are now available for Radio Operator (RADO) and Incident Communications Center Manager (INCM).

The Performance Support Packages for these positions were developed as part of the Incident Performance and Training Modernization effort. These resources support trainees, qualified personnel, and evaluators in their respective roles.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

References:

NWCG Radio Operator Position Page

NWCG Incident Communications Center Manager Position Page