The National Weather Service issued a rare fire tornado – or “firenado” – warning for the Loyalton Fire, which was burning near the California border outside Reno on Saturday, August 15.
The National Weather Service in Reno tweeted that “extreme fire behavior” would continue into Saturday evening with new fire tornadoes possible.
The NWS had earlier issued a tornado warning for the Loyalton Fire area, adding that so-called “firenadoes” were an “extreme weather phenomenon that can occur with rotating fire columns.”
By 5pm, the fire was estimated to have grown to 20,000 acres and was only 5 percent contained. Evacuation orders had been issued for several surrounding areas. In this video, the fire can be seen burning towards the Interstate-395 highway.
Firenados form because of conditions on the ground. Hot, dry air rises rapidly and forms a column. That column of air begins to swirl. As it gains speed, it picks up flaming embers and debris.
A fire whirl, also commonly known as a fire devil, is a whirlwind induced by a fire and often composed of flame or ash. These start with a whirl of wind, often made visible by smoke, and may occur when intense rising heat and turbulent wind conditions combine to form whirling eddies of air.