As wind-driven wildfires spread across Los Angeles in January 2025, fire-spotting technology and computer models aided firefighters in understanding the rapidly changing environment.
Although technology has evolved over time, some techniques remain very similar to those used more than a century ago.
I have spent several decades researching combustion, including wildfire behavior and the technology used to track fires and predict where they might spread. Here’s a quick overview of the key technologies used today.
Spotting fires faster
First, the fire needs to be discovered.
Wildfires are frequently reported by people who see smoke. That has not changed, but other ways to detect fires have evolved.
In the early twentieth century, the newly established United States Forest Service constructed fire lookout towers across the country. The towers were topped by cabins with windows on all four walls, which served as living quarters for fire lookouts.
The system was inspired by the Great Fire of 1910, which destroyed 3 million acres in Washington, Idaho, and Montana, killing 87 people.
Before satellites, fire crews searched for smoke from fire towers throughout the national forests. K.D. Swan, United States Forest Service
Today, cameras monitor many high-risk areas. California has over 1,100 cameras watching for smoke. Artificial intelligence systems continuously analyze images to provide data to firefighters, allowing them to respond quickly. AI is a technique for training a computer program to recognize repetitive patterns, such as smoke plumes in the event of a fire.
NOAA satellites combined with AI data analysis produce alerts over a larger area. They can detect heat signatures, map fire perimeters and burned areas, and monitor smoke and pollutants to determine air quality and health risks.
Forecasting fire behavior
Once a fire is discovered, one of the first tasks for firefighting teams is to predict how the fire will behave so that their limited firefighting resources can be deployed most effectively.
Fire managers have seen a lot of fires and understand the risks their communities face. Today, computer simulations combine data about the terrain, burning materials, and weather to predict how a fire will spread.
Fuel models
Fuel models are based on the ecosystem involved, with fire history and laboratory testing. Chaparral, a shrubland with dense, rocky soil and highly flammable plants in a Mediterranean climate, accounts for a significant portion of wildland fuel in Southern California. Chaparral is one of the fastest-burning fuels, and fires can spread quickly in this terrain.
Human-made structures are a little more complicated. The materials used to build a house, such as wood siding, and the environment surrounding it, such as its proximity to trees or wooden fences, all influence how likely and how quickly it burns.
Terrain is also important because it influences local winds and fire spreads faster uphill than downhill. Terrain data is widely available thanks to satellite imagery and can be easily integrated into computer codes.
Weather also influences fire behavior. Fires require oxygen to burn, and the windier the weather, the more oxygen available to the fire. High winds can also cause embers from burning vegetation to be blown up to 5 miles away, resulting in spot fires that spread quickly.
Today, large computer simulations can predict the weather. Global models cover the entire Earth, while local models cover smaller areas with higher resolution and more detail.
Both provide real-time weather data for use in fire behavior simulations.
Modeling how flames spread
Flame-spread models can then predict the movement of a fire.
Scientists develop these models by studying previous fires and conducting laboratory experiments, which are then combined with mathematical models that incorporate fire physics. These simulations, which use local terrain, fuel, and real-time weather data, can help fire managers predict how a fire will behave.
Examples of how computer modeling can predict fire spread. American Physical Society.
Advanced modeling can take into account fuel details like ground-level plant growth and tree canopies, including the amount of cover, tree height, and tree density. These models can predict when a fire will reach the tree canopy and how this will impact the fire’s spread.
Forecasting helps, but wind can change fast
All of these tools are available to firefighters through computer applications and can assist fire crews as they respond to wildfires.
However, wind can quickly change speed or direction, and new fires can start in unexpected places, so fire managers must be prepared for a wide range of outcomes, not just the ones they see on their computer screens.
Finally, during a fire, firefighting strategy is based on human judgment, informed by experience, science, and technology.
