The Times Australia
The Times World News

.

Wildfire burn scars can intensify and even trigger thunderstorms, leading to catastrophic flooding – here's how

  • Written by William R. Cotton, Professor Emeritus of Meteorology, Colorado State University

Wildfires burn millions of acres of land every year, leaving changed landscapes that are prone to flooding. Less well known is that these already vulnerable regions can also intensify and in some cases initiate thunderstorms.

Wildfire burn scars are often left with little vegetation and with a darker soil surface that tends to repel[1] rather than absorb water. These changes in vegetation and soil properties leave the land more susceptible to flooding and erosion[2], so less rainfall is necessary to produce a devastating flood and debris flow[3] than in an undisturbed environment.

Burn scars can also initiate or invigorate thunderstorms, raising the risk both of flooding and of lightning that could spark more fires in surrounding areas, as my research with fellow atmospheric scientist Elizabeth Page[4] has shown.

Factors contributing to thunderstorms

Three things contribute to the potential for burn scars to fuel thunderstorms: lack of vegetation, reduced soil moisture and lower surface albedo – essentially how well it reflects sunlight. When burned soil is darker, it absorbs more energy from the sun.

These factors contribute to higher surface temperatures over the burn scar area relative to unburned areas nearby. The temperature difference can drive air currents, causing convection – the motion of warmer air rising and cooler air sinking. When that rising warm air draws in more humid air[5] from surrounding areas, it can produce cumulonimbus clouds and even thunderstorms[6] that can trigger rain and flooding.

Fire officials explain how burned land becomes more flood prone.

In an analysis of a flash flood[7] that occurred on burn scars in Australia in 2003, scientists found that the soil’s moisture was low and its albedo in the burn area had fallen from 0.2 to 0.08. To put that into perspective[8], charcoal has an albedo of about 0.04 and fresh snow is nearly the maximum of 1. When the scientists simulated those changes in a computer model, they found that if the land hadn’t been burned, just over a tenth of an inch of rain would have fallen. Instead, those changes led to 1.25 inches and severe flooding.

Studies have found that the intensity of this effect of burn scars on storm potential decreases over time, but the risk remains until the vegetation regrows.

Wildfire burn scars can intensify and even trigger thunderstorms, leading to catastrophic flooding – here's how Burn scars from California wine country’s 2019 Kincade Fire are still evident in 2021. Jane Tyska/Digital First Media/East Bay Times via Getty Images[9]

Riding the thermals

When I used to pilot sailplanes, also known as gliders, I often rode the thermals – upward currents of warm air – in the Santa Catalina Mountains near Tucson and in Colorado’s Front Range. The best locations for catching thermals were on the south and southwest slopes of rugged terrain, where the thermals became chutes of rapidly rising air.

A wildfire in one of these locations would burn more intensely because of the swift air currents, leaving a dark, water-repelling surface[10] with little vegetation behind. With moisture from the Southwest Monsoon[11] that arrives in the region in late summer, these thermal chutes, intensified by burn scars, are prime locations for initiating or intensifying storm-producing cumulonimbus clouds and flooding.

In these arid regions, plant recovery may take three to five years or more, particularly in locations where intense fires burned on south- and west-facing slopes where sunlight is more intense. Many of the record-breaking 2020 wildfires in Colorado and Arizona occurred in mountainous terrain where flash flooding on burn scars has been deadly in the past. These areas will continue to be of particular concern over the next few years.

Wildfire burn scars can intensify and even trigger thunderstorms, leading to catastrophic flooding – here's how Flooding and mud from heavy rain on a burn scar damaged homes in Manitou Springs, Colorado, in 2013. The region was hit with flooding again in 2021. Kathryn Scott Osler/The Denver Post via Getty Images[12]

The effects can linger

How long burn scars will continue to fuel storms depends on how arid the region is and how quickly vegetation recovers.

Forecasters, emergency responders and people living in and near wildfire burn scars need to be aware that these areas are at risk both for potential major flooding and debris flows[13], and for invigorated storms with a potential for heavy precipitation.

[Get our best science, health and technology stories. Sign up for The Conversation’s science newsletter[14].]

Read more https://theconversation.com/wildfire-burn-scars-can-intensify-and-even-trigger-thunderstorms-leading-to-catastrophic-flooding-heres-how-163164

Times Magazine

Headless CMS in Digital Twins and 3D Product Experiences

Image by freepik As the metaverse becomes more advanced and accessible, it's clear that multiple sectors will use digital twins and 3D product experiences to visualize, connect, and streamline efforts better. A digital twin is a virtual replica of ...

The Decline of Hyper-Casual: How Mid-Core Mobile Games Took Over in 2025

In recent years, the mobile gaming landscape has undergone a significant transformation, with mid-core mobile games emerging as the dominant force in app stores by 2025. This shift is underpinned by changing user habits and evolving monetization tr...

Understanding ITIL 4 and PRINCE2 Project Management Synergy

Key Highlights ITIL 4 focuses on IT service management, emphasising continual improvement and value creation through modern digital transformation approaches. PRINCE2 project management supports systematic planning and execution of projects wit...

What AI Adoption Means for the Future of Workplace Risk Management

Image by freepik As industrial operations become more complex and fast-paced, the risks faced by workers and employers alike continue to grow. Traditional safety models—reliant on manual oversight, reactive investigations, and standardised checklist...

From Beach Bops to Alpine Anthems: Your Sonos Survival Guide for a Long Weekend Escape

Alright, fellow adventurers and relaxation enthusiasts! So, you've packed your bags, charged your devices, and mentally prepared for that glorious King's Birthday long weekend. But hold on, are you really ready? Because a true long weekend warrior kn...

Effective Commercial Pest Control Solutions for a Safer Workplace

Keeping a workplace clean, safe, and free from pests is essential for maintaining productivity, protecting employee health, and upholding a company's reputation. Pests pose health risks, can cause structural damage, and can lead to serious legal an...

The Times Features

The Role of Your GP in Creating a Chronic Disease Management Plan That Works

Living with a long-term condition, whether that is diabetes, asthma, arthritis or heart disease, means making hundreds of small decisions every day. You plan your diet against m...

Troubleshooting Flickering Lights: A Comprehensive Guide for Homeowners

Image by rawpixel.com on Freepik Effectively addressing flickering lights in your home is more than just a matter of convenience; it's a pivotal aspect of both home safety and en...

My shins hurt after running. Could it be shin splints?

If you’ve started running for the first time, started again after a break, or your workout is more intense, you might have felt it. A dull, nagging ache down your shins after...

Metal Roof Replacement Cost Per Square Metre in 2025: A Comprehensive Guide for Australian Homeowners

In recent years, the trend of installing metal roofs has surged across Australia. With their reputation for being both robust and visually appealing, it's easy to understand thei...

Why You’re Always Adjusting Your Bra — and What to Do Instead

Image by freepik It starts with a gentle tug, then a subtle shift, and before you know it, you're adjusting your bra again — in the middle of work, at dinner, even on the couch. I...

How to Tell If Your Eyes Are Working Harder Than They Should Be

Image by freepik Most of us take our vision for granted—until it starts to let us down. Whether it's squinting at your phone, rubbing your eyes at the end of the day, or feeling ...