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PMS 437

Fuel Moisture: Vegetative Greenness

Wildland Fire Assessment System (WFAS) AVARR NDVI Greenness Reference is the comprehensive source of images, data archives, and methods for handling.

These images, derived from a satellite sensor, have been produced weekly since 1989, producing a historical record of vegetation phenology that can be used to characterize current vegetation greenness. They can be used to cross-reference with drought assessments and other characterizations of plant development, moisture stress, and curing. Cloud cover can have a significant impact on image quality in portions of the image.

While not an estimate of live fuel moisture, spatial distribution of NDVI estimates and its climatological derivatives can provide important insight to past and current vegetative state and overall landscape flammability during the growing season.

There are several depictions that allow you to evaluate the current NDVI status:

  • Normalized Difference Vegetation Index (ND) is the current derived value from which all the other climatological depictions are derived.
  • Departure from Average Greenness (DA) portrays the absolute difference between current value and the historic average greenness for the corresponding week of the year based on all years 1989-last year.
  • Relative Greenness (RG) portrays how green the vegetation is compared to how green it has been over the historical reference period (1989-last year). Because each pixel is normalized to its own historical range, all areas (dry to wet) can appear fully green at some time during the growing season.
  • Visual Greenness (VG) portrays vegetation greenness compared to a very green reference such as an alfalfa field or a golf course. The resulting image is like what you would expect to see from the air. Normally dry areas will never show as green as normally wetter areas.

This image of Departure from Average Greenness is for September 12, 2011

Departure from Average Vegetative Greenness. Example graphic from the Wildland Fire Assessment System for September 12th of 2011.

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Date:  March 17, 2026
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Please contact: Fire Behavior Subcommittee

NWCG is pleased to announce that the new S-490, Advanced Fire Behavior Calculations (Blended), 2026 course is now available.

This training includes performance-based activities that allow students to apply the knowledge and concepts required for the Fire Behavior Analyst (FBAN), Long Term Fire Analyst (LTAN), and Prescribed Fire Burn Boss Type 1 (RXB1) positions. It supports individuals working towards these incident qualifications.

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S-490, Advanced Fire Calculations (Blended)

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Date:  March 13, 2026
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The NWCG Leadership Committee is proud to announce the recipients of the 2024 Paul Gleason "Lead By Example" awards. Award categories include Initiative and Innovation, Mentoring and Teamwork, Motivation and Vision, as well as a Lifetime Achievement Award.

Congratulations to the awardees:

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Paul Gleason Lead By Example Award

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Leadership Committee

NEW! S-231, Engine Boss Course Available Now

Date:  March 6, 2026
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NWCG is pleased to announce the new S-231, Engine Boss (Single Resource) course is now available on the Wildland Fire Learning Portal (WFLP). Developed through the Incident Performance and Training Modernization (IPTM) effort, this training supports individuals working towards Engine Boss, Single Resource (ENGB) incident qualifications. 

This is a performance-based instructor-led training (ILT) that focuses on the application of ENGB responsibilities during wildland fire operations, emphasizing readiness, information gathering, risk management, engine tactics, and Wildland Urban Interface (WUI) operations. Trainees apply these skills through scenario-based group work and an optional field day that reinforces hands-on engine operation tasks. 

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Date:  March 6, 2026
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NWCG is proud to celebrate 50 years of service to the wildland fire community. Beginning in 1976 with an interagency agreement between the Department of Interior and Department of Agriculture, NWCG has grown to include additional member agencies and is recognized as the standard-setting leader in wildland fire operations.

To honor where we’ve been and highlight where we are going, the NWCG team has created a video showcasing our history and accomplishments. The video is now available on the NWCG website.

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NWCG 50 Year Anniversary Video