Today’s Image of the Day from NASA Earth Observatory features the Wapiti Fire in central Idaho, which was ignited by lightning on July 24, 2024. 

More than a month later, the fire continues to devastate areas across the Boise, Sawtooth, and Salmon-Challis National Forests. 

Explosive fire activity

In its first month, the Wapiti Fire burned about 9,000 acres. It has now grown twelve times larger, burning more than 108,000 acres.

“Fire activity ramped up in late August, expanding its footprint to over 100,000 acres (400 square kilometers) by early September. The Wapiti fire, as well as the Middle Fork Complex fires burning nearby, have spurred evacuation orders and highway and public lands closures,” noted NASA.

By September 3rd, the Wapiti Fire was 2% contained, with firefighting efforts heavily focused on protecting nearby structures and communities, particularly around Stanley and Lowman.

Unpredictable behavior of the Wapiti Fire 

The fire’s behavior has been unpredictable, intensifying during periods of unstable weather, especially when thunderstorms with strong winds have passed through. This has made containment difficult and forced the evacuation of multiple areas, including the communities along Idaho Highway 21. 

Efforts to manage the fire include using air tankers to drop fire retardant and creating containment lines to prevent further spread. However, the fire continues to threaten homes and critical infrastructure, with many structures already lost. 

Local authorities have emphasized the importance of residents being prepared for evacuation, advising them to gather essential documents and possessions in advance.

The fire has led to the closure of vast sections of national forest land, with restrictions expected to remain in place until at least the end of the year, depending on the fire’s progression.

Intensity of the Wapiti Fire 

According to media reports, the intensity of the Wapiti Fire can be largely attributed to certain types of vegetation in the area that rapidly fuel fire. The main fuel in this case is timber in forests that already have “60-80% tree mortality from insects and disease,” 

To make matters worse, the Wapiti Fire is burning in areas that are difficult to reach. The fire is located in steep and rugged terrain within the Boise National Forest that is challenging for firefighting crews to access. The difficult terrain and limited access routes have greatly complicated firefighting efforts.

Lightning-caused wildfires 

Lightning is often responsible for igniting large, destructive fires, particularly in remote and forested areas. These wildfires occur when a lightning strike, typically from dry thunderstorms, ignites dry vegetation like grass, leaves, or trees. 

Contributing factors

The intensity and frequency of these wildfires are influenced by several factors, including the amount of available dry fuel, the local climate, and the specific characteristics of the lightning strike itself, such as its intensity and duration.

Western United States 

In some regions, like the western United States, lightning is responsible for the majority of wildfires, especially during the summer months when thunderstorms are more common. These fires can spread rapidly, driven by winds and the availability of dry fuel, making them difficult to control. 

Lightning-caused wildfires can also lead to the formation of large fire complexes, where multiple fires merge into one, further complicating firefighting efforts.

Ecological role

Interestingly, while lightning-caused wildfires can be destructive, they also play a crucial role in certain ecosystems. These fires can help to clear out dead vegetation, promote new growth, and maintain the health of fire-adapted ecosystems. 

The future of fire weather

The future of fire weather is deeply concerning, as climate change is expected to significantly worsen the conditions that lead to wildfires. 

The climate paradox

As global temperatures rise, the atmosphere will hold more moisture, but paradoxically, many regions will experience more intense and prolonged droughts. This will dry out vegetation, turning forests and grasslands into tinderboxes ready to ignite. 

Additionally, higher temperatures will increase the likelihood of extreme heat waves, which can further desiccate landscapes and create the perfect conditions for fires to spread rapidly and uncontrollably.

Changing precipitation patterns 

Another factor influencing fire weather is changing precipitation patterns. While some areas might experience more rain, others will become drier, with rain increasingly falling in intense, short bursts rather than steady, prolonged periods. This leads to rapid runoff, reducing soil moisture and leaving the ground dry and more susceptible to fire. 

Wind events 

The intensity and frequency of wind events, driven by shifting atmospheric patterns, are also expected to increase, which can fan the flames of wildfires, causing them to spread more quickly and making them harder to control.

Extended fire seasons

In the future, fire seasons will likely become longer, and fires will grow in both size and intensity. Regions that have historically been less prone to wildfires may begin to see more frequent fire events as their climates change. 

The combination of these factors will make managing wildfires more challenging, putting greater pressure on firefighting resources and leading to increased risks to human life, property, and ecosystems.

The future of fire weather is a harsh reminder of the broader impacts of climate change, and the urgent need to adapt to our new reality.

The Wapiti Fire image was captured on August 31, 2024 by the OLI (Operational Land Imager) on Landsat 8.

Image Credit: NASA Earth Observatory 

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–