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PMS 437

Fire Assessment: Observing Current Fire Behavior

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.

  1. Visual Fire Behavior Descriptions
  2. Observing Flame Length vs. Flame Height
  3. Rate of Spread Estimator
  4. Fire Behavior Observation Reports

Visual Fire Behavior Descriptions

This guide identifies key terms for describing fire behavior and provides reference imagery and descriptive detail to aid observation reports.

Fire Observation/Description.

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Observing Flame Length vs. Flame Height

Observing Flames, as proxy for fireline intensity and indicator of tactical limitations, requires careful observation of flame length versus flame height. It is also important to identify whether the observation is for head, flank, or back of the fire.

Flame Length: The distance measured from the average flame tip to the middle of the active flaming zone at the base of the fire. It is measured on a slant when the flames are tilted due to effects of wind and slope.

Flame Height: The average height of flames as measured vertically, up, and down. It is estimated by comparing the flame to a nearby object of known height. Flame height is needed to estimate spot distance from a burning pile.

Flame length is commonly estimated and referenced as analogous to the fireline intensity one would feel at the actively burning perimeter. Flame Height, on the other hand, is what most observers commonly report. Encourage users to identify and observe correctly.

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Rate of Spread Estimator

From the NWCG Standards for Wildland Fire Module Operations, PMS 430.

Fireline observers can use this table to look up a spread rate based on how long it takes the flaming front to move a given distance.

Estimating Rate of Spread.

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Fire Behavior Observation Reports

Fire Behavior Observation Form.

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NWCG Latest Announcements

2025 Paul Gleason Award Winners Announced

Date:  August 13, 2026
Questions? 
Please contact: Leadership Development Subcommittee

The NWCG Qualifications Management Committee (QMC) and Leadership Development Subcommittee (LDSC) are proud to announce the recipients of the 2025 Paul Gleason "Lead By Example" awards. Award categories include Initiative and Innovation, Mentoring and Teamwork, and Motivation and Vision.

Congratulations to the awardees:

  • Hunter Bell, U.S. Forest Service — Initiative and Innovation
  • Shannon Deane, U.S. Wildland Fire Service— Initiative and Innovation
  • Chris Delaney, U.S. Wildland Fire Service — Motivation and Vision
  • Sean Peterson, U.S. Forest Service — Mentoring and Teamwork

References:

Paul Gleason Lead By Example Award

Wildland Fire Leadership Development Program (WFLDP)

Leadership Development Subcommittee

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.

References:

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

Technical Service Bulletin: 03-002-21