The fire tornado, or pyrotornado, is a rare meteorological phenomenon that occurs when intense combustion combines with specific atmospheric conditions. Though often conflated with smaller, common fire whirls, a true fire tornado is a powerful and destructive vortex of fire, ash, and smoke. Understanding these spinning columns is important as large-scale wildfires become more frequent across the globe.
What Exactly Is a Fire Tornado?
A fire tornado is a rotating column of air, often visible due to smoke and flame, that forms over an intense fire. Scientists distinguish between a common fire whirl and the much rarer, more powerful fire tornado. A fire whirl is generally a small, short-lived vortex, typically measuring only 10 to 160 feet in diameter, driven primarily by surface-level heat.
A fire tornado, by contrast, operates on a massive scale, often dominating the entire fire environment. These large vortices can reach heights of over 17,000 feet and diameters exceeding 1,000 feet, comparable to a conventional tornado. Rotational wind speeds can be destructive, sometimes surpassing 143 miles per hour, qualifying them as an EF-3 on the Enhanced Fujita scale. The formation of a true fire tornado is often associated with a pyrocumulonimbus cloud, a giant, smoke-filled cloud that behaves like a thunderstorm.
The Mechanics of Fire Whirl Formation
The physics behind these rotating fire columns requires three specific ingredients: intense heat, atmospheric instability, and a source of rotation. Intense heat from a large, concentrated fire creates a powerful, buoyant updraft as the air above the fire becomes superheated and rapidly rises. This upward movement is the first step in forming a vortex, pulling in cooler air toward the fire’s center.
The atmosphere must already contain ambient vorticity, which is a pre-existing horizontal or vertical spin in the wind layers. This rotation can be introduced by wind shear, which is a difference in wind speed or direction over a short distance. As the rising column of hot air draws the surrounding air inward, it concentrates this pre-existing spin.
This process is governed by the conservation of angular momentum, similar to how an ice skater pulls their arms in to spin faster. As the large column of rotating air is stretched upward by the intense thermal updraft, its diameter shrinks, causing the rotational speed to drastically increase. This accelerated rotation forms the tight, low-pressure core of the fire whirl, creating a self-feeding cycle that can rapidly intensify into a devastating fire tornado.
Documented Instances and Recent Events
Historically, fire tornadoes have been documented in catastrophic events, such as the firestorms following the 1923 Great Kanto Earthquake in Japan. Recent, scientifically confirmed events have changed how meteorologists view fire behavior. A widely studied example is the fire tornado that formed during the 2018 Carr Fire in California, which was officially rated as an EF-3 tornado due to its wind speeds and damage footprint.
The most recent confirmed, large-scale fire tornado event occurred during the Deer Creek Fire in Utah. On July 12, 2025, this wildfire spawned a strong, nearly stationary fire tornado that the National Weather Service confirmed as an EF-2. This event generated winds strong enough to cause structural damage.
Another significant event occurred in 2020 during the Loyalton Fire on the California-Nevada border, where the National Weather Service issued its first “fire tornado warning.” The fire generated three fire tornadoes, two of which were rated EF-1. While smaller fire whirls are documented regularly during wildfire seasons, the 2025 Deer Creek Fire event serves as the latest confirmed instance of a true, tornadic-scale fire tornado, highlighting the continued threat of these rare phenomena.