Fire Behavior Field Reference Guide, PMS 437

NWCG Committee Realignment Website Updates: Content will continue to be updated over the coming days as we work through final reviews and adjustments, and all publications and products are currently under revision.

PMS 437 Cover. Decorative.
The Fire Behavior Field Reference Guide is intended to be used in conjunction with the NWCG Guide to Fire Behavior Assessment, PMS 437-1.

The Fire Behavior Field Reference Guide contains helpful references to the factors from the fire triangle (fuels, weather, and topography), including features that are vital to field-going fire managers. It provides detail about the fire behavior models and tools used to estimate fire ignition, spread/size, fireline intensity, and crown fire potential. The reference material will assist with decision support using various tools and methodologies.

The guide will be updated twice annually (April and November) as necessary to reflect the most recent science and technologies for field use to help improve and assist with decision support, fireline safety, and fire behavior interpretation. As new and improved safety zone research is obtained and available for distribution, the Fire Behavior Field Reference Guide will be updated to house that information. YouTube videos will be uploaded periodically to provide additional supporting documentation:
www.youtube.com/user/FireBehaviorSC.

The Fire Behavior Field Reference Guide is developed and maintained by the Fire Behavior Subcommittee (FBSC), under the direction of the Fire Environment Committee (FENC), an entity of the National Wildfire Coordinating Group (NWCG).

While they may still contain current or useful information, previous editions are obsolete. The user of this information is responsible for confirming that they have the most up-to-date version. NWCG is the sole source for the publication.
Comments, questions, and recommendations shall be submitted to the appropriate agency representative assigned to the FBSC. View the complete roster.

The National Wildfire Coordinating Group (NWCG) provides national leadership to enable interoperable wildland fire operations among federal, state, Tribal, territorial, and local partners. NWCG operations standards are interagency by design; they are developed with the intent of universal adoption by the member agencies. However, the decision to adopt and utilize them is made independently by the individual member agencies and communicated through their respective directives systems.

Last Modified / Reviewed: April 01, 2025

Print PDF

NWCG Latest Announcements

LMC Equipment Bulletin 26-001: Aquatic Invasive Species – Seasonal Reminder for Mussels

Date: July 30, 2026
Questions?
Please contact: Equipment and Technology Subcommittee

The Logistics and Equipment Management Committee (LMC) issued Equipment Bulletin 26-001: Aquatic Invasive Species - Seasonal Reminder for Mussels, reminding the wildland fire community that aquatic mussels continue to be a problem. Mussels rapidly colonize hard and soft surfaces, including aquatic plants and fire equipment, clogging pipes, fouling motors, disrupting water systems, and impacting native species.

To help prevent their spread, fire personnel must follow the decontamination procedures outlined in the NWCG Guide to Preventing Aquatic Invasive Species Transport by Wildland Fire Operations, PMS 444. Additionally, report any sightings immediately to your Lead Resource Advisor and include clear, close-up photos (with a pen or your hand for size reference) and location details.”

Read the complete LMC Equipment Bulletin 26-001, to learn more.

References:

NWCG Alerts

LMC Equipment Bulletin 26-001: Aquatic Invasive Species - Seasonal Reminder for Mussels

NWCG Guide to Preventing Aquatic Invasive Species Transport by Wildland Fire Operations, PMS 444

Intermediate Faller (FAL2) Position Task Book Update

Date: July 24, 2026
Questions?
Please contact: Tree Felling Subcommittee

NWCG Operations Management Committee (OMC) has issued an update to the NWCG Position Task Book for Intermediate Faller (FAL2), PMS 311-91. To ensure clarity for both trainees and evaluators, the updated FAL2 Position Task Book (PTB) explicitly states who is authorized to sign off on your tasks:

“Evaluators must be qualified as a FAL2, or an Advanced Faller (FAL1).”

If you are currently working out of a previously published version of the FAL2 PTB, you do not need to restart. However, OMC highly encourages you to take the following step to prevent any confusion in the field:

Print and replace the updated evaluator information page (page 2) in your current physical PTB.

References:

Intermediate Faller (FAL2) Position Page

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

NWCG Position Task Book for Intermediate Faller (FAL2), PMS 311-91

Equipment Advisory 26-001: Potential Front Driveline Joint Failure on 2018 and Earlier Ram Pickups

Date: July 10, 2026
Questions?
Please contact: Equipment and Technology Subcommittee

The Logistics/Equipment Management Committee (LMC) has released Equipment Advisory 26-001: Potential Front Driveline Joint Failure on 2018 and Earlier Ram Pickups. This advisory highlights multiple U.S. Forest Service regions reporting front driveline joint failure incidents.

This advisory recommends firefighters and fire managers to:

Follow all Ram-issued inspection, maintenance, and service guidance for front driveline joints.
Consider installing a driveline loop.
Coordinate with fleet managers and service providers to determine the most appropriate driveline loop kit for each pickup.

For further details, please refer to the complete advisory.