Skip to main content

PMS 425

4. Building a Mental Model of the Weather Forecast

A mental model is your representation of the world around you and a mental model of a weather forecast is your perception of how the weather will play out over time. A mental model will help you visualize the upcoming shift and will ensure that you have the best understanding of how the weather will evolve through the operational period.

Building a mental model takes several steps:

  1. You must first fully understand the current forecast.
    1. Ensure you have the correct forecast for your area and operational period by reading the header information.
    2. Look for any headlines such as Advisories, Watches, or Warnings. If a headline is in the forecast, make a note of when it is valid for and what type(s) of hazards are expected.
    3. Read the discussion. The discussion should give you an idea of the larger scale weather pattern and how the forecast variables will evolve through the day. Focus will be given to any significant weather that is expected to impact safety or operations.
    4. Read through the Mandatory Elements. Compare with the discussion to see how the forecast elements may evolve with time through the operational period. Focus on frontal passages, wind shifts, and/or thunderstorm timing, if applicable.
    5. Read through the Optional Elements. These will help you understand information about stability, smoke impacts, and favored spotting direction. Also read the extended forecast to better understand the potential for high-impact weather in the coming days.
    6. Briefly discuss the forecast with your fellow firefighters. Ask yourself and others if the forecast makes sense and if you do not understand any portion of it, be sure to contact the meteorologist.
  2. Look at the current weather observations. If you are on an assignment, take observations first thing in the morning. If you are on station, either go outside, and take observations, or look online at nearby weather stations as shown in Figure 1. This is important because the current weather is the starting point, and the forecast is the pathway for the weather through the shift. If the morning temperature is 70 °F and the forecast calls for a high temperature of 95 °F, you know that you will see an increase in temperature through the day. Ask yourself several questions:
    1. How will the temperature increase from now until then?
    2. Is there an inversion that may break suddenly and increase the temperature? If so, what time will it break?
    3. Is there a cold front moving through that may create a situation where the high temperature is reached early in the day?

​These questions can likely be answered by reading the forecast discussion and examining other elements within the forecast.

Fire Weather Observations table from mesowest.

Figure 1: Fire weather observations from Mesowest.

  1. If you are assigned to an incident or are heading to an emerging incident, your mental model needs to include knowledge of the terrain you are working in. Examine a topographic map (Figure 2) of the fire area and look at where the fire is relative to terrain features. This will help you better understand how the wind will flow through the terrain, how the different aspects will warm/cool with a changing sun angle, and how any local winds might affect your area.

Division personnel examining a topographic map in the back of a truck tailgate.

Figure 2: Division personnel examining a topographic map on the Carpenter Road Fire.

  1. Verify your mental model. As the day progresses, continue to either take weather observations or look at the data from nearby weather stations, like shown in Figure 3. Once again, ask yourself several questions:
    1. Is the temperature and relative humidity following the common diurnal pattern? If not, what might be causing the change?
    2. Is the wind speed and direction similar to the forecast? Is topography playing a large role in altering the speed and direction from what the forecast says?
    3. Is there cloud cover? How is it evolving? Are there thunderstorms forming? If so, can you contact dispatch or the meteorologist to find out where they are at and where they are going? Ask about the potential for gusty outflow winds.
    4. Is the forecast generally on track? If you notice that the weather is differing markedly from the forecast, you may need to contact the meteorologist and ask for an update and/or discuss your concerns.
A permanent RAWS outside.

Figure 3: A permanent RAWS.

Building a complete mental weather model is essential and going through these steps will help you better understand and follow the weather conditions as you complete your shift. Remember Standard Firefighting Order #1: Keep informed on fire weather conditions and forecasts.

The fire environment is constantly changing. Building a mental weather model and then verifying that model will help you to understand what is causing the transitions you may be observing in the fire on the ground. Recognize that the two other components of the fire environment—fuels and topography—will also play a role in the behavior of the fire. Watch for times when each of the elements of the fire behavior may align as these conditions represent the most critical times for large fire growth. Fire is dynamic, but by being a student of fire, you can better anticipate and react to the consequential changes fire behavior.

Last Modified / Reviewed:

NWCG Latest Announcements

NWCG Committees Observe Suicide Prevention Awareness Week: September 7-13, 2025

Date: Sep 5, 2025
Questions? Please contact:
Mental Health Subcommittee

The NWCG Mental Health Subcommittee (MHSC) and Risk Management Committee (RMC) recognize the unique challenges and demands faced by the wildland fire community. The MHSC and RMC know that we are all stronger together and believe in fostering a culture of support, understanding, and resilience.

Suicide Prevention Awareness encourages us to actively connect with and support each other. For more information that could make a difference for yourself or someone else please review the materials and resources provided for the 2025 Suicide Prevention Awareness Week.

References:

2025 Suicide Prevention Awareness Week Materials and Resources

NEW! Incident Performance and Training Modernization Story Map Now Available

Date: Aug 26, 2025
Questions? Please contact:
National Wildfire Coordinating Group

NWCG is excited to announce the launch of the Incident Performance and Training Modernization (IPTM) Story Map, a new interactive resource that showcases how NWCG is transforming wildland fire training and qualifications through a performance-based system.

Since its launch in 2023, IPTM has made major strides in updating how we manage incident positions:

  • 36 incident positions now have new Incident Position Standards and Next Generation Position Task Books available for field use
  • 6 more incident positions are nearing completion
  • 111 total incident positions are being analyzed through the IPTM initiative

The Story Map guides you through the IPTM process, highlights key accomplishments, and outlines what’s ahead. Whether you are a trainer or a trainee, this tool offers valuable insight into the modernization effort shaping the future of wildland fire training and qualifications.

This effort would not be possible without the contributions of NWCG staff, NWCG committees, and hundreds of subject matter experts across the wildland fire community.

References:

IPTM Story Map

Incident Performance and Training Modernization Webpage

NEW! S-290, Intermediate Wildland Fire Behavior (Blended) Available Now

Date: Aug 15, 2025
Questions? Please contact:
Fire Behavior Subcommittee

NWCG is excited to announce that the S-290, Intermediate Wildland Fire Behavior (Blended) training is now available on the Wildland Fire Learning Portal. S-290 (Blended) training combines online training and instructor-led training components that support individuals working towards any Single Resource Boss or Fire Effects Monitor incident qualifications.

This second course in the series collectively serves to develop fire behavior prediction knowledge and skills, and provides more detailed information on fuels, weather, and topography that affect wildland fire behavior for safety purposes.

Students are required to finish the prerequisite S-190, Introduction to Wildland Fire Behavior, before enrolling in S-290, Intermediate Wildland Fire Behavior (Blended).

References:

S-290, Intermediate Wildland Fire Behavior (Blended)

S-190, Introduction to Wildland Fire Behavior

Wildland Fire Learning Portal

NEW! S-271, Helicopter Crewmember (Blended) Now Available

Date: Aug 14, 2025
Questions? Please contact:
Interagency Helicopter Operations Subcommittee

The S-271, Helicopter Crewmember (Blended) is now available. Developed through the Incident Performance and Training Modernization (IPTM) effort, this training supports individuals working towards Helicopter Crewmember (HECM) incident qualifications. 

S-271, Helicopter Crewmember (Blended) training combines online training and instructor-led training components. This course is designed to provide students with the knowledge and skills necessary to perform the duties of the HECM position, as described in the NWCG Incident Position Standards for Helicopter Crewmember, PMS 350-22.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

References:

S-271, Helicopter Crewmember (Blended)

NWCG Helicopter Crewmember (HECM) Position Page

Wildland Fire Learning Portal