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PMS 425

PMS 425

NWCG Guide to Fire Weather Forecasts, PMS 425

1. Introduction

2. Fire Weather Forecast Variables

3. Types of Fire Weather Forecasts

4. Building a Mental Model of the Weather Forecast

NWCG Guide to Fire Weather Forecasts: Introduction

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.

Fire weather forecasts are likely one of the first professional introductions firefighters have to meteorological information. They may even be the first thing a firefighter reads each day when they get to their duty station. Forecasts convey certain atmospheric variables. The intent of this guide is to describe best-practices on how to interpret and use the weather information provided.

Fire weather forecasts include several components:

  • Header information
    • Date and time the forecast is valid for
    • Applicable forecast headline
  • Forecast discussion
  • Mandatory forecast elements of sky/weather
    • Temperature
    • Relative humidity (RH)
    • Wind
  • Optional forecast elements that may include the chance of:
    • Wetting rain
    • Mixing height
    • Transport wind
    • Smoke dispersal
    • Inversion information
    • Haines Index
    • Lightning activity level (LAL)
    • Extended forecast or outlook

Each forecast element is generally given only one value per operational period.

The weather forecast is a static document that may not adequately describe the changes one sees in the weather through an operational period. For example, fire weather forecasts only provide the high temperature for day operational periods and the low temperature for night operational periods. It is left up to the firefighter to interpret how fast and when the temperature will rise and/or fall during their shift. Consistent weather is a firefighter’s friend. It is the change in weather conditions that prove problematic and sometimes fatal to operational resources. This publication provides context and interpretation guidelines for fire managers and fireline personnel to make improved decisions with safety in mind.

There are links to online resources throughout this publication. Visit these resources, as additional information and graphics are often provided. The most frequently linked resource is the Agriculture Handbook 360: Fire Weather… A Guide for Application of Meteorological Information to Forest Fire Control Operations, PMS 425-1. Refer back to it as you learn more about fire weather forecasts.

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NWCG Latest Announcements

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

NEW! NWCG Standard Operating Procedures, PMS 900

Date:  July 9, 2026
Questions? 
Please contact: NWCG Staff

NWCG is excited to announce the publication of the NWCG Standard Operating Procedures, PMS 900.

The new publication establishes general, consistent, and uniform standards for conducting business with the National Wildfire Coordinating Group.

References:

NWCG Standard Operating Procedures, PMS 900

Quarter Four Materials for the 2025-2026 Wildland Fire Leadership Campaign Now Available

Date:  July 8, 2026
Questions? 
Please contact: Leadership Development Subcommittee

NWCG is excited to announce that Fourth Quarter materials for the 2025/2026 Wildland Fire Leadership Campaign are now available. This annual initiative offers all students of leadership and wildland fire management an opportunity to engage with essential leadership skills and knowledge needed to lead effectively in dynamic environments.

Quarter Four materials focus on Leadership Level 4: Leader of Leaders (Provide Direction). Leadership Level 4 is where you are setting the conditions for others to do things well, even when you are not present. This quarter focuses on equipping experienced leaders with skills to provide direction, build trust across teams, and foster strong decision making. 

References:

2025/2026 NWCG Leadership Campaign - Leadership Levels

Wildland Fire Leadership Development Program

Leadership Development Subcommittee