CFFDRS System Overview

Introduction
Use of English Units
Wind Observations
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).

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.

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.

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.

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.

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).

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.

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

The Incident Position Standards and Next Generation Position Task Book are now available for Medical Unit Leader (MEDL)

Date: October 16, 2024
Contact: Incident Medical Subcommittee

NWCG is excited to announce that the NWCG Incident Position Standards for Medical Unit Leader, PMS 350-39 and NWCG Position Task Book for Medical Unit Leader (MEDL), PMS 311-39 are now available.

The Performance Support Package, which for MEDL 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.

References:

NWCG Medical Unit Leader Position Page

NWCG Incident Position Standards for Medical Unit Leader, PMS 350-39

NWCG Position Task Book for Medical Unit Leader (MEDL), PMS 311-39

The Wildland Fire Learning Portal is Now Available

Date: October 9, 2024
Contact: Wildland Fire Learning Portal

The Wildland Fire Learning Portal (WFLP) is back online following a migration to a new learning management system (LMS) application. The WFLP team is actively addressing any issues that may arise as a result of the update, and appreciates your patience as the team works to enhance your experience. NWCG will share information from the WFLP as it is available.

Should you have any issues with accessing or using the WFLP, please use the link below to submit a ticket through the Help Center.

References:

Wildland Fire Learning Portal

Wildland Fire Learning Portal Help Center

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.