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CFFDRS System Overview

  1. Introduction
  2. Use of English Units
  3. Wind Observations
  4. Fire Intensity Measures

Introduction

The Canadian Forest Fire Danger Rating System, as shown in these flow charts, is a comprehensive system of tools designed to evaluate environmental factors that influence the ignition, spread, and behavior of wildland fire. Additional detail about the system and its subsystems can be learned from an introductory certificate online course and direct access to the YouTube videos that support it:

CFFDRS Components

The system had its origins from early efforts dating to the 1920s and the development of the Tracer Index, a forerunner of the Fine Fuel Moisture Code (FFMC).

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The Fire Weather Index System. This process flow chart outlines the system inputs, as well as the array of output codes and indices

Fire Weather Index (FWI) System Process Flow Chart

The FWI system was developed and introduced across Canada in 1970. Due to its simplicity in terms of data required and outputs produced, it is used both globally and within many regions around the world.

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The Fire Weather Index System. This process flow chart outlines the system inputs, as well as the array of output codes and indices.

 

Fire Behavior Prediction (FBP) System Process Flow Chart

The FBP system tools were released in interim form in 1984, with a more formal introduction in 1992, and revisions in 2008.

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The Fire Behavior Prediction System. This process flow chart outlines the system inputs, as well as the array of primary fire behavior and secondary fire growth characteristics.

Additional systems for fuel moisture (e.g. hourly FFMC and Grass Fuel Moisture) and ignition have followed.

There are several important distinctions for NFDRS and NFBPS users.

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Use of English Units

All the CFFDRS tools and references produced by the Canadian and Provincial governments, as well as applications produced internationally, use the metric system for all measured values. For the most part, measures referenced here are in English units to facilitate utility and use in the United States.

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Wind Observations

This table provides a quick reference to aid conversion between 10m, 20ft, unsheltered Eye Level (EL Op) observations, and Forecast/Airport winds. 

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Open Windspeed Chart: Use only 10m for effective windspeed

CFFDRS weather observations, provided to the system for both FWI and FBP calculations, generally conform to familiar fire weather standards. These standards can be reviewed in the weather guide table referenced above. However, wind observation standards conform to the international 10m height as opposed to the NFDRS 20-foot height standard.

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This depiction highlights the difference in height standard among fixed and handheld wind sensors used in fire management applications.

(Andrews, 2012)

CFFDRS models and tools do not expressly apply relationships between the standard 10m wind measurements and others that U.S. users may be familiar with. Both 20-foot and eye level winds are commonly referenced and reported from U.S. RAWS observing locations and from the fireline.

Further, wind speeds reported from Airport ASOS (Automated Surface Observing System) and provided in National Weather Service forecasts generally report higher wind speed, where surrounding terrain is flat with little variation in vegetation height or structural interference, and is highly correlated with forecast wind speed provided in the National Digital Forecast Database (Lawson and Armitage, 2008).

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Surrounding terrain and surface characteristics affect the windspeed measured by sensors. Compares the speeds measured at generally flat/smooth surfaces around airport sensors, more variable and rougher terrain found in forest RAWS settings, and the highly modified results obtained in urban settings.

(Lawson & Armitage, 2008)

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Fire Intensity Measures

A major adaptation in U.S. tools and references, with uncertain validity, is the use of flame length for fire intensity outputs in the Fire Behavior Tables. FBP outputs (kW/m) were converted to BTU/ft/sec using standard conversions and then to flame length using the formula:

Flame Length = .45*"BTU/Ft/Sec"^.46

This table identifies the CFFBP Fire Intensity thresholds in kW/m and the corresponding values in English units (BTU/ft/sec) and flame length in feet. These thresholds are consistent with commonly held flame length thresholds for fire safety interpretations in the U.S. system.

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The Fire Intensity Class Conversion Table shows the relationship among English and metric representations of fireline intensity at key threshold levels.

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NWCG Latest Announcements

2025 Professional Reading Program

Date: February 18, 2025
Contact: Wildland Fire Leadership Development Program (WFLDP)

The Wildland Fire Leadership Development Program is announcing the 2025 Professional Reading list! The goal of the annual reading list is to promote the reading and discussion of the books throughout the year.

The five books chosen for this year are: Surf When You Can by Brett Crozier, Man’s Search for Meaning by Viktor E. Frankl, Elephant Company by Vicki Constantine Croke, Simply Managing by Henry Mintzberg, and Chop Wood Carry Water by Joshua Metcalf.

References:

Professional Reading Program

Task Group Volunteers Needed to Update the Property Loss or Damage Report, OF 289

Date: February 5, 2025
Contact: Julie Bennett, Incident Business Committee Chair

The Incident Business Committee (IBC) is requesting volunteers for a new task group to revise the 1981 version of the Property Loss or Damage Report, OF 289 and create an incident replacement job aid. The volunteers may be recruited from within or outside the Geographic Area Incident Business Committees.

References:

IBC Memorandum 25-02

IBC Correspondence

2025 Updates to the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1

Date: February 4, 2025
Contact: Incident and Position Standards Committee

The NWCG Incident and Position Standards Committee has updated the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1. 

These updates address changes to incident position names and requirements for qualification, training, and experience. Updates related to the implementation of Complex Incident Management (CIM) are also included.  

The NWCG Wildland Fire Position Qualification Flowchart, PMS 308 has also been updated to reflect the recent changes.

References:

NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1

NWCG Wildland Fire Position Qualification Flowchart, PMS 308

NWCG Memo: 2025-01 January 2025 Updates to the NWCG Standards for Wildland Fire Positions Qualifications, PMS 310-1

NWCG Equipment Technology Committee Releases Safety Warning: 25-001 Non-specification fire shelters

Date: January 15, 2025
Contact: Equipment Technology Committee

The Equipment Technology Committee (ETC) has released Safety Warning: 25-001 Non-specification fire shelters. Non-specification fire shelters claiming to meet Forest Service (FS) fire shelter specification 5100-606 were first found in February of 2023. As of September 2024, non-specification shelters are again being advertised and sold on the open market.

This Safety Warning outlines details and recommended procedures to purchase FS specification shelters made with materials and components that meet performance criteria and toxicity testing requirements outlined in FS Specification 5100-606. 

For additional information on identifying non-specification shelters, please view ETC Safety Warning 23-01.

References:

ETC Safety Warning 25-001: Non-specification fire shelters

NWCG Equipment Technology Committee

ETC Safety Warning 23-01