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PMS 437

Fire Assessment: Evaluating Expected Fire Behavior

  1. What Makes a Good Analyst
  2. Selecting the Best Tool
  3. Basic Fire Behavior Tools
  4. Spatial Analysis Tools
  5. Online Resources

What Makes a Good Analyst (Mark Finney...FBSC YouTube Video)

Time: 07:19

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Selecting the Best Tool

The fire spread and intensity models have been configured in a variety of forms to address fire potential in different temporal and spatial configurations. This table can help focus the assessment with the most helpful information.

How will the tool help answer your question?How will fire behavior change with the next big change in fire environment?
Sensitivity Analysis
Where will fire go today and how long will it take?
How will fire behavior vary across areas of interest during the burn period?
Where will fire go over several days given changing weather as well as fuel and terrain?What risk do identified values face over a given planning period?
Tool or Model
  • BehavePlus
  • Lookup Tables
  • Nomograms
  • Nomographs
  • Nexus
  • FLAME/CPS
Short-Term Fire Behavior (STFB) or FlamMap Minimum Travel Time (MTT)  (Finney 2002).Near-Term Fire Behavior (NTFB) or FARSITE     (Finney 1998).
  • Fire Spread Probability (FSPro).
  • Uses Minimum Travel Time (MTT)  (Finney 2002).
Best Use, Calc TimeFirelineIncident/Event, 15 min to 1 hour.Incident Planning, 1 to 3 hours.Risk Assessment, 2 or more hours.
Forecast HorizonSingle PeriodUp to 3 days if weather persistent.Up to 6 days (evaluate forecast confidence).One week to 30 days.
WeatherSingle weather (wind and fuel moisture) scenario.Single weather (wind and fuel moisture) scenario over duration of run.Hourly, variable weather (wind and fuel moisture) over duration of run.Short term forecast plus ERC seasonal trend after that produce range of daily weather scenarios.
Gridded WindNoYes (WindNinja)NoNo
SpottingYes
Max Spot Distance, Probability of Ignition.
Yes
Spotting Distance and Frequency
(one ember per node; spotting probability value higher than NTFB; start with .10% spotting probability).
Yes
Spotting Distance and Frequency
(16 embers per vertex; spotting probability value lower than STFB; start with .05%).
Yes (like STFB)
Principal Output(s)

Not Spatial

  • Rate of Spread.
  • Flame Length.

Spatial

  • Major flow paths and arrival times.
  • Perimeters.
  • Fire behavior grids.

Spatial

  • Progression perimeters.

Spatial

  • Probability contours.

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Basic Fire Behavior Tools

Manual (Fireline) Methods:

Lookup Tables, Nomograms, and Nomographs are all direct implementations of the surface fire spread and spotting models and are constructed for use without computers.

  • Lookup Tables and Fire Behavior Nomograms are constructed for only the original 13 fuel models and represent only surface fire behavior. They provide simple means to estimate fire behavior on the fireline based on observed fine fuel moisture, fuel model, wind, and slope. They can be found in the Surface Fire Section, Surface Fire Behavior Lookup Tables.
  • Spotting Nomograms are for single torching trees only and do not account for terrain features. They can be found in Crown Fire Behavior Section, Spotting Fire Behavior.
  • Fire Behavior Nomographs, PMS 436-3, include only the 13 original fuel models.  Nomographs for Estimating Surface Fire Behavior Characteristics (Scott 2007) include both the 13 original fuel models (Anderson, 1982) and each of the additional 40 models implemented more recently (Scott and Burgan, 2001).

FLAME and the Campbell Prediction System are systems rooted in the concept that in the fire response to a fire, firefighters need to have a thought process that can help them identify what the fire is doing, how that relates to the fire environment (wind, slope, fire flammability), and what the upcoming changes will produce. Further, they focus on firefighter safety implications and encourage means of organizing thoughts for briefing firefighters.

While neither is in widespread use, they represent important attempts to blend the fire behavior prediction models and processes with fireline operations.

The Fireline Assessment Method, FLAME (Bishop, 2007) expects users to:

  1. Describe current fuels, winds, and terrain influences and the fire spread it is currently producing
  2. Identify what the Next Big Change will be during the burn period (slope reversal, fuel type change, forecasted change in the wind)
  3. Apply multipliers for windspeed, fuel, and slope to produce new estimates of fire spread to apply tactically.

Campbell Prediction System(CPS) identifies “three primary forces causing variations in fire behavior: wind slope and pre-heat.” It highlights the need to:

  1. Evaluate the specific “alignment of [these] forces” on each side of a fire and place on the landscape, and recognize the “fire signature, [or] the observed fire behavior” it produces.
  2. Identify “trigger points where a change in the alignment of forces will change the fire behavior [signature], creating either opportunity or danger.”

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BehavePlus

A desktop computer application that is composed of a collection of mathematical models that describe fire behavior, fire effects, and the fire environment based on specified fuel and moisture conditions. The program simulates rate of fire spread, spotting distance, scorch height, tree mortality, fuel moisture, wind adjustment factor, and many other fire behaviors and effects; it is commonly used to predict fire behavior in multiple situations.

Online Reference and Learning Resources

Due to periodic updating, users should check the Splash information found in the help menu to determine the version currently installed. Install the latest version. The latest version can be identified and downloaded from the BehavePlus Fire Modeling System website.

A collection of publications that support the BehavePlus Modeling System

A comprehensive set of training resources can be found at the BehavePlus online reference Tips and Reference Materials.  

An online self-paced course can be found among the self-study courses at the Frames Online Course System.

Creating a Workspace

To take full advantage of the BehavePlus system, users should consider recording their inputs, assumptions, and configurations within the BehavePlus file structure rather than on paper worksheets provided in the past. There are now enough options within the system that only knowing the fire environment inputs may not be sufficient to duplicate the results. Use these few guidelines to establish a BehavePlus Workspace and record all work, including documentation, by saving in the appropriate file format provided in the software.

In the BehavePlus File menu, the workspace submenu allows the user to open an existing workspace, create a new empty workspace, or clone the currently open workspace to a new location. The default workspace is located with the program files and is opened by default each time BehavePlus is opened.

Users should consider either creating a workspace on external storage (network folder or USB flash drive) or cloning the default workspace to one of those locations at the end of a work session when data files need to be shared, backed up, or archived.

There are individual folders for worksheet files, fuel model definition files, fuel moisture scenario files, individual run files that include system settings and modeling inputs, and unit settings. Work should be stored there.

Models and Tools Specific to BehavePlus

  • Two-Fuel Model Projection.
  • Special Case Fuel Models (Palmetto-Gallberry and Western Aspen).
  • The Tools Menu includes Units Converter, Relative Humidity estimator, Fine Dead Fuel Moisture (Fosberg) Estimator, Slope from Map Inputs estimator, and Sun-Moon Calendar.

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NEXUS

NEXUS 2.1 is crown fire hazard analysis software that links separate models of surface and crown fire behavior to compute indices of relative crown fire potential. Use NEXUS to compare crown fire potential for different stands, and to compare the effects of alternative fuel treatments on crown fire potential. NEXUS includes several visual tools useful in understanding how surface and crown fire models interact.

The NEXUS2 installation file is nexus2.1.exe. Save this file to your machine and install from there; admin rights required. Alternatively, you may download the NEXUS21.zip archive which contains the installation program plus the associated Readme.txt and ReleaseNotes.txt files.

Mobile Apps

Wildland Toolkit 

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Spatial Analysis Tools

There are a number of different fire behavior analysis systems that incorporate different combinations of the models referenced here.  This a good guide to the different modeling systems, their inputs, and how they are used.

Scott, Joe H. 2012. Introduction to Wildfire Behavior Modeling. National Interagency Fuels, Fire, & Vegetation Technology Transfer.

FARSITE

FlamMap

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Online Resources

Wildland Fire Decision Support System (WFDSS)

Interagency Fuels Treatment Decision Support System (IFTDSS)

Alaska Fire Weather and Fire Behavior Prediction Tool

Great Lakes Fire Weather and Fire Behavior Prediction Tool

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NWCG Latest Announcements

NEW! S-212, Intermediate Faller (Online) Course Available Now 

Date:  April 23, 2026
Questions? 
Please contact: Hazard Tree and Tree Felling Subcommittee

NWCG is pleased to announce that the new S‑212, Intermediate Faller (Online), course is now available on the Wildland Fire Learning Portal (WFLP). This second course in the series provides students with the knowledge and skills required to perform the duties of an Intermediate Faller (FAL2), as described in the FAL2 Incident Position Description. This course is intended for individuals seeking to advance from Basic Faller (FAL3) to FAL2.

S‑212, Intermediate Faller is a fully online, self‑paced training program consisting of 13 units. Learners will engage with interactive, scenario‑based content designed to progressively build foundational skills and knowledge essential for the FAL2 role.

Students must be qualified as a Basic Faller (FAL3) prior to enrolling in S‑212, Intermediate Faller course.

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 2027.

References:

S-212 Intermediate Faller (Online)

RMC Memo 26-01: Transition Plan for Implementing Updates to Intermediate Faller (FAL2) Position Qualifications

Intermediate Faller (FAL2) Position Page

NWCG Standards for Wildland Fire Chainsaw Operations, PMS 212

New Aircraft Flight Schedule Form, PMS 249

Date:  April 17, 2026
Questions? 
Please contact: National Coordination System Committee

A new publication from the National Coordination System Committee (NCSC) is now available. The NWCG Aircraft Flight Schedule Form, PMS 249, will be used for aviation crews and dispatch to share flight information that is needed for resource tracking, and if needed, for emergency procedures.

For further details, please contact your NCSC representative. 

References:

NCSC Memo 26-01: Implementation of NWCG Aircraft Flight Schedule Form, PMS 249

NWCG Aircraft Flight Schedule Form, PMS 249

New Glossary Term for Review

Date:  April 15, 2026
Questions? 
Please contact: Data Standards and Terminology Board (DSTB)

The Data Standards and Terminology Board is requesting feedback on a new glossary term: Resource Protection Measure (RPM).

The proposed definition is: Practical guidance provided for incident personnel in a manner in which incident objectives can be achieved while reducing impacts to identified resources across the landscape. RPMs are informed by, but not restricted to, Minimum Impact Strategies and Tactics (MIST).

Please review, share with your subgroups, and provide feedback as appropriate through the following form: Request Feedback The comment period will close May 10, 2026.

Thank you for your engagement in the NWCG glossary process – your participation is key to our success.

References:

Glossary Request Feedback

Quarter Three Materials for the 2025-2026 Wildland Fire Leadership Campaign Now Available

Date:  April 1, 2026
Questions? 
Please contact: Leadership Committee

NWCG is excited to announce that Quarter Three materials for the 2025/2026 Wildland Fire Leadership Campaign are now available. This annual initiative offers all students of leadership and wildland fire management an opportunity to engage with essential leadership skills and knowledge needed to lead effectively in dynamic environments.

Quarter Three materials focus on Leadership Level 3: Leader of People (Develop Intent). Leadership Level 3 is where your values, your team, and your influence come together. Leaders of People put their teams first, build trust, and lead with authenticity. They mentor future leaders and shape decisions up and down the chain.

References:

2025/2026 NWCG Leadership Campaign - Leadership Levels

Wildland Fire Leadership Development Program

Leadership Committee