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Extreme Fire Behavior – I

 

Fire managers make decisions throughout the day on how to suppress fires and best use resources while protecting life and property. This Standard Firefighting Order depicts a firefighter observing increased fire behavior during a time of day when temperatures are high and relative humidity is low.

3. Base all actions on current and expected behavior of the fire. A firefighter looks at his watch, which reads 2 PM, while a fire actively grows in steep terrain and heavy timber.

3. Base all actions on current and expected behavior of the fire.

Read about all 10 Standard Firefighting Orders.

Changes in fire behavior have always been present in cases of shelter deployment. It is critical for firefighters to maintain situation awareness of live and dead fuel moisture conditions, as well as predicted and current weather conditions. As fire behavior moves from mild to moderate to extreme, it is critical to act decisively regarding the changing situation.

Discuss the following indicators of extreme fire behavior:

  • Relative humidity less than 15%.
  • 1-hour fuel moisture less than 5%.
  • Transition from surface to crown fire.
  • Smoldering fires that exist in the early part of the day are beginning to burn very actively as the day progresses.
  • Approaching thunderheads with dark clouds beneath.
  • Presence of dust devils indicating atmospheric instability.
  • Increased spotting.
  • Sudden calm.
  • High clouds moving fast in a direction that is different from surface wind.
  • Predicted Haines Index of 5 and 6 in those areas where this level is a good indicator of atmospheric instability.
  • Fire whirls.

Image of a fire whirl twisting up from a forest fire.

 

Category
Weather - Fire Behavior

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NWCG Latest Announcements

Make an Impact: Serve the Wildland Fire Community as an IPTM SME!

Date:  June 11, 2026
Questions? 
Please contact: NWCG SME Specialist

Note: Positions with an * will last approximately 6 months.
Positions with ** will last 12 - 18 months.

NWCG is seeking experienced wildland firefighters and support personnel to serve as Subject Matter Experts (SMEs) for the Incident Performance and Training Modernization (IPTM) initiative. IPTM aims to transition NWCG’s training and qualification system to a performance-based model by updating position descriptions, Incident Position Standards, Next Generation Position Task Books (Next Gen PTBs), and training where needed.

NWCG is currently recruiting SMEs for the Fall 2026 positions listed below:

  • Equipment Manager (EQPM)*
  • Fixed Wing Parking Tender (FWPT)**
  • Mixmaster (MXMS)*
  • Public Information Officer Complex (PIOC)*
  • Retardant Crewmember (RTCM)*
  • Strike Team Leader Crew (STCR)*
  • Strike Team Leader Engine (STEN)*
  • Strike Team Leader Heavy Equipment (STEQ)*
  • Task Force Leader (TFLD)**
  • Wildland Fire Investigator (INVF)** 

Projects begin October 2026. Sign up by July 10, 2026, at the link below and review the attached document for additional details. 

References:

NWCG SME Interest Sign-up

IPTM Subject Matter Expert Duties and Expectations Document

Incident Performance and Training Modernization (IPTM)

RMC Safety Bulletin 26-001: Rhabdomyolysis in Wildland Firefighters

Date:  May 28, 2026
Questions? 
Please contact: Risk Management Committee

The Risk Management Committee (RMC) has issued Safety Bulletin 26-001: Rhabdomyolysis in Wildland Firefighters. Research from 2016 to 2025 shows that 88 cases of rhabdomyolysis (rhabdo) were reported. Analysis of reports from eSafety, the Safety Management Information System (SMIS), and the Wildland Fire Lessons Learned Center (LLC) indicates that rhabdo is common during this time of year due to Work Capacity Tests and contributing factors such as weather, hydration, nutrition, and medication or supplement use.

RMC issued this safety bulletin to raise awareness in the Wildland Fire Community, and to provide research findings and educational resources that support reducing future cases of rhabdo.

References:

NWCG Alerts

RMC Safety Bulletin 26-001: Rhabdomyolysis in Wildland Firefighters

NEW! D-110, Expanded Dispatch Recorder Course Available Now

Date:  May 15, 2026
Questions? 
Please contact: Dispatch Position and Curriculum Management Subcommittee

NWCG is pleased to announce the new D-110, Expanded Dispatch Recorder (Instructor-led) course is now available on the Wildland Fire Learning Portal (WFLP). Developed through the National Coordination System Committee, this course introduces the structure and function of expanded dispatch, the qualities of an effective dispatcher, and provides hands-on experience with the Interagency Resource Ordering Capability (IROC) system. 

The D-110, Expanded Dispatch Recorder course aligns with the competencies and duties outlined in the NWCG Incident Position Standards for Expanded Dispatch Recorder, PMS 350-59, and is designed for individuals with no prior experience who may be called upon to support dispatch operations.

References:

D-110, Expanded Dispatch Recorder (Instructor-Led)

Expanded Dispatch Recorder (EDRC), Position Page

NWCG Incident Position Standards for Expanded Dispatch Recorder, PMS 350-59

Wildland Fire Learning Portal

Leadership Committee IAP Flyer Now Available

Date:  May 8, 2026
Questions? 
Please contact: Leadership Committee

The NWCG Leadership Committee promotes and enables leadership development across the wildland fire service. The committee provides education, training opportunities, and support for leadership innovation and best practices throughout the community.

A new IAP flyer is now available on the committee website, offering an overview of the products, curriculum, and learning opportunities the Leadership Committee develops. This resource is ideal for posting in your office, sharing with new employees, or distributing through your incident management teams to engage new voices in the leadership journey and reinforce a culture of self‑reflection, development, and growth.

References:

Leadership Committee 2026 IAP Flyer