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PMS 437

Fire Danger Background

  1. General References
  2. 78/88 Version NFDRS Structure
  3. 2016 Version NFDRS Structure
  4. NFDRS Version Comparison

General References

Fire Danger ratings are an effective part of daily risk rating and operational preparedness for fire management agencies across the world. Chapter 10 – Preparedness of the Interagency Standards for Fire and Fire Aviation Operations outlines processes and resources applied in the development of standard Fire Danger Operating Plans in the United States.

Included in Fire Danger Operating Plans are:

  • Specification of fire danger ratings.
  • Identification of climatological thresholds for administrative purposes. Default thresholds include the 90th and 97th percentile values for key indices in the applied system. The Bureau of Land Management (Department of Interior) uses the 80th and 95th percentiles instead.
  • Communication of those danger ratings, including both internal and external forms.

Some valuable links:

A variety of fire weather systems are applied in danger rating around the United States. There are primarily two systems used in fire danger operating plans.

U.S. National Fire Danger Rating System (NFDRS):

First introduced in 1964, NFDRS has been updated in 1972, 1978, 1988, and now 2016 to integrate newer science and improved processing. This guide will compare important aspects of the 1978, 1988, and 2016 versions, detail important outputs, and describe primary components and indices. More information about the system and the latest update to it can be found at:

NFDRS 2016 Information Page

NWCG Fire Danger Subcommittee Website

The Canadian Forest Fire Danger Rating System (CFFDRS) Fire Weather Index (FWI) System

CFFDRS was introduced in Canada in 1970. Implemented in Alaska and the lake states of Michigan, Minnesota, and Wisconsin in the early 1990's. Details about CFFDRS are included a separate section of this guide. The following websites provide data access:

Other tools, formulations, and applications are used locally across the country. Some examples are highlighted later, in the Fire Danger References Section.

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78/88 Version NFDRS Structure

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Structure and Process Flow of the 78/88 National Fire Danger Rating System.

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2016 Version NFDRS Structure

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Structure and Process Flow of the 2016 National Fire Danger Rating System.

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NFDRS Version Comparison

Category 78 Version 88 Version 2016 Version
Fuel Models and Settings
  • 20 NFDRS specific fuel models
  • Grass identified as annual or perennial
  • Shrub type not detailed
  • Specific revisions to 3 of the 78
  • Version fuel models (C, E, and N)
  • Grass identified as annual or perennial
  • Shrubs identified as evergreen or deciduous
  • Reduction to five new 2016 Version NFDRS specific fuel models (V, W, X, Y, Z)
  • Grass identified as annual or perennial
  • Shrub type not detailed
Climate Class
  • Used to determine dormant 100 hours, 1000 hours, and live fuel moistures
  • Used to specify duration of green-up process and influence curing rates
  • Used to determine dormant 100 hour, 1000 hour, and live fuel moistures
  • Station Catalog identifies location as Humid with on/off toggle. Influences Max SC and Moisture of Extinction
Manual Inputs
  • Observation type
  • Snow Flag
  • Wet Fuel Flag
  • Green-up/Freeze Flag
  • State of the Weather
  • Observation type
  • Snow Flag
  • Wet Fuel Flag
  • Season
  • 1 hour = 10 hour?
  • Daily Herb & Woody Greenness Factor
  • State of the Weather
  • Snow Flag
1 hour & 10 hour Fosberg-71 Model Fosberg-71 Model Nelson Model
100 hour & 1000 hour Fosberg-71 Model Fosberg-71 Model Nelson Model
Herbaceous and Woody Fuel Moisture Content Herb fuels classified as dead when dormant.

Transition from dormant/deal fuel moisture to live/full green-up based on climate class in spring 1000 hour based live moisture trend and load transfer		 Herb fuels classified as dead when dormant.

Season/Greenness factor based live fuel moisture trend/load transfer unless fuels declared dormant.		 Herb fuels classed as dead when dormant.

Green Season/Live Fuel Index based moisture trend and load transfer.

 
Drought Fuel Load Transfer   KBDI used to signal initiation and amount of fuel load transfer. KBDI used to signal initiation and amount of fuel load transfer.
SC, IC, ERC, BI Models unchanged.

Outputs will vary based on differences from new fuel moisture models and new fuel model definitions.		 Models unchanged.

Outputs will vary based on differences from new fuel moisture models and new fuel model definitions.		 Models unchanged.

Outputs will vary based on differences from new fuel moisture models and new fuel model definitions.

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NWCG Latest Announcements

NWCG Training Catalog now on Wildland Fire Learning Portal

Date: April 25, 2023
Contact: NWCG Training  

The National Wildfire Coordinating Group (NWCG) has migrated the training catalog from the NWCG website to the Wildland Fire Learning Portal (WFLP) as part of our ongoing efforts to streamline processes and improve efficiency. To facilitate this transition, the training catalog remains available on www.nwcg.gov through April 2024.

Starting May 2024, the training catalog will no longer be accessible on www.nwcg.gov. However, you can still access the complete training catalog by logging in as a guest to the WFLP.

References:

Wildland Fire Learning Portal

 

NWCG Website Migration

Date: April 01, 2024
Contact: NWCG Webmaster

The National Wildfire Coordinating Group is thrilled to announce a significant upgrade to https://www.nwcg.gov, involving a comprehensive redesign of over 7,000 web pages. This enhancement is focused on improving user experience. The migration to the new NWCG website will commence on April 2, 2024, starting at noon EST and is expected to take a few hours. 

During the migration period, as the www.nwcg.gov domain-name-location updates across the Internet, you might encounter either the current or the new site depending on your location. We request your patience during this transition. If you are not redirected to the new site by April 3, 2024, we recommend clearing your browser’s cache and refreshing the page.

Please note that while navigating the revamped website, there may be instances of broken links or errors. Our dedicated web migration team has made significant efforts to minimize such issues prior to launch and will promptly address any that arise via use of analytic reports. We value your patience and understanding as we work towards enhancing your overall website experience.

WFSTAR 2023 Year in Review and 2024 Core Component Module Packages Available

Date: March 6, 2024
Contact: Joe Schindel 

The 2023 Fire Year in Review module and 2024 Core Component Module Packages for RT-130, Wildland Fire Safety Training Annual Refresher (WFSTAR) are now available on the NWCG website. The 2024 Core Component Module Package provides all content needed to deliver RT-130.

 

References:

WFSTAR 2023 Fire Year in Review module

WFSTAR 2024 Core Component Module Packages

2024 NWCG Executive Board Annual Letter

Date: March 6, 2024
Contact: NWCG

The NWCG Executive Board is privileged to share with you the 2024 NWCG Executive Board Annual Letter. As we look into the future and navigate an incredibly complex and dynamic environment, we must remain focused on our mission while actively engaging in national conversations regarding numerous wildland fire initiatives. In 2024, we prioritize building upon our successes and committing to continuous improvement. Key priorities and considerations for this year include: 

  • Determining Core Workload
  • Ensuring Incident Performance and Training Modernization (IPTM) Success
  • Improving Efficiencies
  • Firefighter Health and Wellness
  • Engagement in National Conversations

Together we will continue to make significant strides in the challenging and vital work that lies ahead. 

 

References:

2024 NWCG Executive Board Annual Letter